# Marks Holt 75



## dnalot (Oct 20, 2019)

Time to start a new project. This build will be of a Holt 75 engine built to the plans offered by George Britnel. Thanks George, nicely done. No instructions provided, just the drawings so its going to be a great strategy game. I expect we will be seeing others building this engine to George's plans.

I like to start with the hardest part whenever I can because if its beyond my ability there is no point in going on. So for this build its the 4 journal crankshaft. I have turned a couple of single journal crankshafts and a two journal 90 degrees off crankshaft. So I am starting with some confidence but nevertheless will wait and see if I am successful before posting.

I do not plan to do a step by step log on every part, but the Crankshaft deserves a little more than a “here it is” treatment. Such a pity that the part will be hidden from view when the model is completed.

The crank is being cut from a 12” length of 1144 stressprof steel. I would have preferred a piece of rectangular material but was only able to locate that material locally in round stock. The first step was to turn the ends and the center bearing.

Cutting speed was 70 RPM and a feed of of 20 turns per inch for roughing and 114 turns per inch for the final cut. Cutting depth of .020” I stopped .0004 short of the .5” diameter needed then used cloth sandpaper to the final diameter. The first end was turned between centers. The second end I inserted the part into a collet chuck to keep from marring the surface of the completed end.


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## dnalot (Oct 20, 2019)

It cost me a days work taking the material down to thickness. A rectangular piece of steel would have been so much nicer. My little mill was able to take a .010” cut with a .5” HSS bit just fine.

Additional cuts on the mill were made along the way at each journal to remove excess material before returning to the lathe.


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## dnalot (Oct 20, 2019)

The blocks that provide multiple centers were notched to transfer the torque load to the web so as not to put any strain on the end of the crank shaft. Working from the center towards the chuck kept any strain on the delicate areas to a minimum.


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## dnalot (Oct 20, 2019)

Before using the parting tool method below I tried using a narrow deep HSS cutter. I ground it several different ways but could never get it to cut without chattering and it tended to wiggle back and forth.

I cut the center journal first and then worked my way towards the chuck I used a cutoff tool with a carbide insert. Plunge cutting about .050” deep per pass. After the cut was about a third of the way to my target I would stop and then take a HSS tool bit to dress down the side of the cheeks. At 2 thirds of the way I dressed the cheeks again. From there I used the parting tool again plunge cutting to within .005” of the target dimension then started very light cuts panning the tool back and forth until reaching the target dimension. The parting tool left a very nice surface only requiring a little sanding with a cloth backed 320 grit paper. I will smooth the journals a bit more when I fit the bearings to them. A final dressing of the cheeks and off to the next journal.


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## dnalot (Oct 20, 2019)

Is it perfect? When does that ever happen? I was able to turn the journals to the correct diameter without any problems but the cheeks varied a bit in thickness at first until I worked out what tools worked best. Is it straight? You tell me, when supported at the bearing point at each end the run-out at the center bearing is .0012”. So the center bearing is .0006” out of place. And the run-out at the ends where the flywheels will be mounted is .0017” at one end and .0018 at the other.

So here it is, I'm happy with it so the build is on. But winter is nearly here and I live nestled in the mountains between Mt Rainier and Mt Saint Helens. I need to spend some time splitting firewood, servicing the generators and putting the heater wires on the roofs to keep the snow load from becoming to great. After that I will start the crankcase parts.


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## sition (Oct 20, 2019)

Nice!!


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## gbritnell (Oct 21, 2019)

Excellent job! The tolerances you hit are just fine. Given about .0015 clearance for oil it should spin over nicely in the bearings.
gbritnell


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## Sparticusrye (Oct 21, 2019)

Very Nice work, an excellent start.  I'll be watching as you progress.

I just finished a Poppin vacuum engine on Friday and the little crankshaft was difficult and it only has one journal.  I bent it on the first try and ended up making a built up crank.


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## retailer (Oct 21, 2019)

Congrats on getting the crank finished with such a small amount of run out - those that have built running engines say it is all downhill from here


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## dnalot (Oct 22, 2019)

Thanks for the comments guys. I will be back at it soon and will make more posts as the crankcase progresses. 

Mark T


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## CFLBob (Oct 22, 2019)

Looks really good Mark!  

I'm commenting here more for me than to say anything important.  The idea is that the HMEM will send me an email when you get back to it and update, so I can keep up with your progress.  I bought George's plans for the Holt, but I've told myself to finish my first IC engine, a Webster, before I move on to a four cylinder.  

Bob


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## dnalot (Nov 4, 2019)

Crankcase halves



For cutting the crankcase I will be using the manual CnC method “crank and crank and crank” I bought a 24” length of aluminum 6061 2.5” by 3.5”. I will be able to cut all the aluminum parts with this and a little chunk of material to spare.

I started by facing one surface on both the crankcase and the pan and then fixing them together with two sided tape.

From there I surfaced all the other sides making a block with parallel sides and squared ends.

The next step was to drill and tap for the screws that hold the two case halves together. As you can see I started roughing out the outside shape for the pan.


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## dnalot (Nov 4, 2019)

With fingers crossed I clamped the block on the mill and set about drilling for the crank bearing and the camshaft. Its over 6 “ to the far end so I had to flip the material over and repeat the above steps. The holes were then reamed to size from one end only. Surprisingly everything lined up and a test shaft that has a close slip fit passed trough and could be turned with little force. I then cut the pockets for the crankshaft end bearing holders.

The drawings showed the end bearing holders with some added detail. I elected making the part in two pieces to simplify and to make it easier to get a nice machined finish.


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## dnalot (Nov 4, 2019)

The bearing holders are reamed to to a close slip fit for now so I can use my test shaft to hold the mounts to the block accurately for drilling and taping.

I have been sweating getting the block to this stage. Getting the shafts trough straight and true was one of my biggest worries for this build. I have a long way to go but I think its all down hill from here.










Now I'm off to start hollowing out the block, shaping the exterior, drilling and taping holes and such. I will post updates as I go.


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## gbritnell (Nov 5, 2019)

I'm following along. Great work so far! Should you have any questions please don't hesitate to ask.
gbritnell


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## dnalot (Nov 5, 2019)

gbritnell said:


> I'm following along. Great work so far! Should you have any questions please don't hesitate to ask.
> gbritnell



Hi George, just a heads up. Your drawings are missing a gear.I figured it out to be a 1" gear with a press fit.


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## gbritnell (Nov 5, 2019)

I will check it out this evening and get back to you.
gbritnell


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## gbritnell (Nov 5, 2019)

Hi dnalot,
I checked the drawings. Crankshaft drawing shows 32 DP 1.00 gear. Camshaft shows 32 DP 2.00 gear. Gear box drawing shows 32 DP 1.00 gear which goes on gear shaft (with hub) and 32 DP 1.00 gear (no hub) which goes on distributor shaft and a 32 DP .50 gear. Those are all the gears that are needed. 
gbritnell


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## dnalot (Nov 6, 2019)

My bad George, My tired old eyes missed the note about the gear. I should get thicker glasses. 

Mark


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## gbritnell (Nov 6, 2019)

Not a problem. Anytime someone finds an error or omission I appreciate the feedback.
gbritnell


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## dnalot (Nov 16, 2019)

My next step is to hollow out the upper half of the crank case. This required three stages, first the center area that is flat, followed by the two angled sides. I plunge cut for the rough out. Its a lot of material for a small mill so it took some time. Next I made the cutouts for the center bearings, cut the slots for the bearings splash oilers and bored the holes for the cylinders and push-rods.


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## dnalot (Nov 16, 2019)

The center bearing blocks are of bearing bronze. Nasty stuff to work with. To lay out where to bore the hole I used a dial indicator and the mills DRO to figure out the vertical measurement. For the lateral measurement I measured from the jaws of the squishing device. (or I could have said I measured from the jaws of my vice but you guys have beat me up for that before) I then used a pointed center to locate my layout for the hole. I screwed up my vertical calculations and my holes ended up .005” to low. I keep an assortment of beer and pop cans for times like this. So from a pop can I cut some .0055 shims to but under the bottom bearing block.


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## dnalot (Nov 16, 2019)

Before drilling the hole for the shaft through the bearing block I drilled the holes for mounting the block to the case. And I made some very close fit dowels to hold the halves together while I bored the big hole for the shaft and cut the blocks to their correct width. The main end bearing holders were fitted with pressed in bronze bushings that fit the test shaft snugly. Using the test shaft the center bearings were located and drilled and taped for mounting shoulder screws.


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## dnalot (Nov 16, 2019)

The bushings and bearing blocks were fit snug to the test shaft and now need to be reamed up to the correct size for the crankshaft. To do this I made an adapter to fit over the shank of the ream. This I hoped would keep the ream in line. I reamed one outside center bearing block and the main end bearing then flipped the setup around and reamed the other end. After that I reamed the center bearing block using one of the already reamed blocks as a guide and continued through to the far end. And then with crossed fingers I assembled the bearings with the shaft in place. With fingers It turned a bit stiff with a slight bump. A little oil helped with the stiffness but the bump remained. So I put some lapping compound on the bearing surfaces and turned the crank at slow speed with a drill motor for about five minuets. After cleaning up the shaft and bearings I reassembled and the shaft turned smoothly without the bump. Run out at the end of the longest shaft end was .0032” so the end of the shaft is about .0016 out of place.










Next up, hollowing out the lower case. I need to be away for a few days but will get started when I return. 

Mark T


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## kuhncw (Nov 16, 2019)

Very nice work, Mark.

Chuck


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## stevehuckss396 (Nov 17, 2019)

Just went back ans started from the beginning. I will be following this one for sure. Thanks for sharing.


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## dnalot (Nov 29, 2019)

Time to hollow out the lower crankcase and shape the outside of both crankcase halves. So this part of the project isn't difficult to do, its just very time consuming. There were a lot of setups so plenty of room to make a mistake. I got lucky and everything went smoothly.

The drawings show some curved areas on the inside of the lower crankcase half. I opted to just do some faceted cuts to safe time. The difference is very slight.


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## dnalot (Nov 29, 2019)

Shaping the outside of the case halves does require some curved surfaces. I like to redraft all of the parts so I can take measurements from points I can reference. Using my drawing of the case I made a cutting chart for the rough out and finish cuts. The first rough out was with a 1/2” flat cutter followed by a .313 ball nose cutter. The finish cut was done with a .187 ball nose cutter.


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## dnalot (Nov 29, 2019)

This part has given me CNC envy. I have a CNC router that I built back in 1999. I occasionally do small aluminum parts on it but the 30,000 RPM spindle is way to fast. I would like to build a CNC mill but I'm to old now to justify the expense.

So there it is, just need to spend a day sanding the curved areas smooth and the case halves will be done. Now I really don't mind sanding because while beer and machining don't mix, beer and sanding do. I used a 1 inch pad sander with 100 grit paper to take the rough areas down. It actually went quickly. I followed with a .5 inch pad sander to get into the corners and some paper glued to a Popsicle stick to get into the tightest areas.


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## dnalot (Nov 29, 2019)

And then to give the parts a cast look I sandblasted with fine sand. The final step was to anodize the part to give the surface a tough shell. The parts were then sealed with hot penetrating oil. 

Final photo of all the parts made so far assembled.

At this point I have options as to what I do next. I'm thinking the gear case(s) make the most sense, followed by the gears and cam shaft.


Mark T


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## gbritnell (Nov 30, 2019)

Wow! Outstanding job on the crankcase. The anodizing looks great.
gbritnell


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## michelko (Nov 30, 2019)

Realy cool. I also purchased Georges nice  plans and i will follow your progress . I am working on a metric conversion and drawing the whole engine with Inventor.
After that i will start with my build.

Regards Michael


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## johnmcc69 (Nov 30, 2019)

The crankcase turned out beautiful! Great finish.
 I'm looking forward to more.

 John


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## Jeffrey Lehn (Nov 30, 2019)

Outstanding !


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## dnalot (Dec 1, 2019)

Thanks for taking the time to comment guys. Besides my UPS driver your about my only contact with the outside world. 

Mark


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## MrMetric (Dec 3, 2019)

I really like the way you made a faux casting (my term) look on this.  It looks great!

Can you give some specifics on the hot penetrating oil comment? Was this a bath or just rubbed in? I'm assuming a bath given the 'hot' comment, and if so, how long and what temperature?  Thanks.


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## dnalot (Dec 3, 2019)

Normally after anodizing aluminum you immerse the part in a sealing solution for about 15 minuets in a water soluble sealer at about 200 degrees. I just substituted penetrating oil for the sealer. It stinks and smokes a lot so I do it outside. It gives a darker final finish. 

Mark


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## dnalot (Dec 12, 2019)

This post is about the large gear case and the details I omitted from the main bearing holders earlier.

The only photo I have of the parts for the main bearing holders is this one where I am using my lathe as a shaper to rough out the half round feature. I had used the mill to shape the block and remove most of the material for the half round areas. When completed the parts were glued to the bearing holders with locktite.


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## dnalot (Dec 12, 2019)

To start the body of the gear box I used the lathe to machine detail to the back of the box. I then turned the material over in the lathe to face the other side and bring it down to the proper thickness. After taking the first cut I measured the thickness and found it varied. So change of plans, will cut to thickness on the mill. The sun went down and came up again the next morning. And I forgot about taking the part down to thickness.


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## dnalot (Dec 12, 2019)

The next step required a turntable. A little back story here and then I will circle back. My table is a 6” model I bought from Grizzly. It looks like a Vertex but has no name on it. On another thread “Rotary table problems” a member “petertha” provided links to two videos showing how to improve the Vertex table. My table would wander off center. Turned out the table was a very sloppy fit to the bearing in the base. I am fixing that with a bushing. The bigger problem was the backlash. Almost a full degree. Well the video showed how to adjust this. There is a setscrew that acts like a stop on an eccentric that engages the worm gear. Well my table has such a hole but there was no setscrew and the hole didn't go through the casting and was not threaded. Turns out there is a broken off tip of a drill bit in the hole. Scratching my head about that. Guess Vertex didn't want that table but Grizzly was OK with it.

So I have a crappy table and that makes the gear box a little harder to make. With so much backlash I opted to shape the outside of the box and its lid by plunge cutting. To mount the part to the table I attached a piece of marine plywood to the table and faced it with the mill. I then cut a pocket in the center of the table to the size of the boss on the backside of the gearbox. And I made two adapters for centering the part for cutting the end pockets for the smaller gears. It was while I was drilling and taping the holes for the lid to the gear box that I remembered I had not cut the part down to thickness.


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## dnalot (Dec 12, 2019)

The plunge cutting left a rough surface but a few hours with a Dremel fitted with a pad sander and some fine files had it ready for buffing.

Every thing assembled well and aligns with the camshaft. So I'm thinking legs next as I repair my turntable. Lot of the upcoming parts will need a turntable.

Thanks for watching, Mark T


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## Cogsy (Dec 12, 2019)

Wow - nice work on the gearbox. It looks CNC'd!


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## michelko (Dec 13, 2019)

Very cool stuff can´t wait to start my build.
Keep on posting 

Michael


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## gbritnell (Dec 13, 2019)

Beautiful!


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## vandal968 (Dec 13, 2019)

Where can information be found about these Holt plans?  Google comes up with nothing, searching this site shows some builds to no info on cost or how to purchase them.


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## michelko (Dec 13, 2019)

vandal968 said:


> Where can information be found about these Holt plans?  Google comes up with nothing, searching this site shows some builds to no info on cost or how to purchase them.


Hi,
You should contact gbritnell he made the nice imperial plans to build the engine from scratch without castings. At the moment i am converting this into metric with inventor. Sometimes there will be a set of metric plans.
Michael


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## Brian Rupnow (Dec 13, 2019)

Amazing work. The finished engine will be beautiful.---Brian


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## bobden72 (Dec 13, 2019)

So tell me when you cut the outside of the gear box you said you just plunged cut, are you just using the outline you have drawn on it as your guide.  If so I am very impressed as I have a similar job to tackle and was wondering how to approach it.


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## dnalot (Dec 13, 2019)

bobden72 said:


> So tell me when you cut the outside of the gear box you said you just plunged cut, are you just using the outline you have drawn on it as your guide. If so I am very impressed as I have a similar job to tackle and was wondering how to approach it.



Yes but I used the turntable to rotate the part for most of the cuts. Around the screw holes I just eyeballed it.  I kept the zero point on the z axis just below the surface so I could see where exactly the cutter was. The cuts were very light so I used the drill feed for lowering and raising the spendel.  I'm not very good at explaining things, I hope this helps.

And thanks for the comments guys. 

Mark T


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## kvom (Dec 14, 2019)

Pretty amazing work with just an iffy rotab.  Made me tired imagining it.


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## Rickus (Dec 14, 2019)

Just want to verify this.  You aren't using CNC in the machining, strictly manual turning and milling right?  I have the Smithy Granite 1040 my wife got for me last month ( big upgrade from the 18 year old HF 9x20 and HF mini mill ) and really want to make engines come 2020.  Not wanting to go CNC and prefer doing everything manually for more pride in my projects.


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## dnalot (Dec 14, 2019)

Rickus said:


> Just want to verify this. You aren't using CNC in the machining, strictly manual turning and milling right? I have the Smithy Granite 1040 my wife got for me last month ( big upgrade from the 18 year old HF 9x20 and HF mini mill ) and really want to make engines come 2020. Not wanting to go CNC and prefer doing everything manually for more pride in my projects.



That's correct, no CNC, just a lot of manual work. It actually went fairly fast.

Mark T


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## Rickus (Dec 14, 2019)

Outstanding!  Now that I am wrapping up my big projects, ie: finished my ultralight airplane, and about to finish home conversion of our motorcycles to trikes, I will slow down and begin following your example in earnest.  Just can't find manual machining much any longer now that CNC has come down in price and people prefer that.  Have you other projects I/we can look at?


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## bobden72 (Dec 14, 2019)

Thanks for your reply Mark and yes understand completely, how long approximately to carve it out.  I will give it a go on my new project.


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## dnalot (Dec 14, 2019)

Rickus said:


> Outstanding! Now that I am wrapping up my big projects, ie: finished my ultralight airplane, and about to finish home conversion of our motorcycles to trikes, I will slow down and begin following your example in earnest. Just can't find manual machining much any longer now that CNC has come down in price and people prefer that. Have you other projects I/we can look at?



Yes, see this link https://www.homemodelenginemachinist.com/threads/gatling-gun.31594/  and go to post 6

Mark T


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## dnalot (Dec 14, 2019)

bobden72 said:


> Thanks for your reply Mark and yes understand completely, how long approximately to carve it out. I will give it a go on my new project.



It took about 7 hours start to finish to make the gear box. About 2 hours of that was sanding and filing. Before I started I probably spent 20 hours thinking about how to go about it. Slow witted but nimble fingers.

Mark T


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## dnalot (Dec 16, 2019)

This is a minor update. Legs. Small parts but a big deal. The engine can now sit on its own legs and is stable to work on. The plans called for the feet to point outward from the block. I opted to face them inward so that I can use their mounting bolts to mount a box for the ignition system on one side and a name card on the other. I also picked up some lose ends like cutting the groves for the crankshaft o-rings and drilled and taped the hole for the pan's drain plug.

The black chunk of metal the engine is sitting on is a slab of cast iron for making the two flywheels and the cylinder heads.

Will be starting the small gearbox soon.




Mark T


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## Rickus (Dec 16, 2019)

Since you are using "O" rings, could you educate me on determining the groove size to fit them or "O" ring size to fit grooves?


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## dnalot (Dec 16, 2019)

Rickus said:


> Since you are using "O" rings, could you educate me on determining the groove size to fit them or "O" ring size to fit grooves?



There is probably a scientific way, but I just use the chart on this page http://www.row-inc.com/sizes.html

Mark T


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## Rickus (Dec 16, 2019)

Never thought to look for a chart!  Thanks.


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## dnalot (Dec 31, 2019)

Sorry guys but this is my last post for the year.

Took the time to fix my rotary table. Almost no backlash, what a difference that makes. The small gearbox is mostly just a repeat of the big one. Also made the five bearings for the camshaft and three bearings for the small gear box. And a roughed out blank for the camshaft. The photo of the camshaft shows it being marked for the layout. for cutting I kept most of the shaft in the  collet to start with and would work near the chuck. As I completed a section I would expose anther inch or so until all the detail was cut. 

Time to make some gears now. It has been a while sense I cut any gears. This time I have the hardware to make it easier. I have an indexer with a stepper motor and a controller.

See https://www.homemodelenginemachinis...y-table-for-dummies.26744/page-18#post-331050

I made my setup near the beginning of this thread. You can see my setup at post 53. I have used it a lot and it works very well. Well except for gears that is. The limiting factor is that the number of teeth must divide into 360 with no more than 2 decimal places. If there are more than two there will be an error that will accumulate. I needed a 32 tooth gear and that was no problem the indexer worked great. But I Also needed a 64 tooth gear. 360 divided by 64 gives you 5.625 degrees per tooth. The indexer would round that to 5.63, and that will leave you with a very skinny 64th tooth. To get around this I first made 32 cuts. next I would setup for 64 cuts but only made one cut before resetting for 32 cuts. That gives a serviceable gear with every other tooth being a little fat and the others a bit skinny.

Everything fit together nicely and turns smoothly.

Mark T


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## dnalot (Dec 31, 2019)

See you next year

Mark T


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## dnalot (Dec 31, 2019)




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## dnalot (Jan 8, 2020)

Another part completed. This time its the camshaft. The Adrino controlled indexer made quick work of cutting the cam lobes. To form the apex of the lobes I made a custom cutter. Filing and polishing took about as much time as the machining.

Next I think will be the cylinders. The plan calls for aluminum jackets but I plan on using steel to allow for some fabrication of the part.

Mark T


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## michelko (Jan 9, 2020)

Hi, very nice work.
Waht material did you use? I think the cams and the followers will be unhardened?

Regards Michael


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## dnalot (Jan 9, 2020)

michelko said:


> Waht material did you use? I think the cams and the followers will be unhardened?



The plan called for the cam to be W-1 drill rod, not hardened. And the followers W-1 drill rod hardened.

Mark T


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## kuhncw (Jan 9, 2020)

Mark, 

Thanks for a very well written and illustrated build thread.  

Very nice work.

Regards,

Chuck


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## Robert Ritchie (Jan 9, 2020)

dnalot said:


> Another part completed. This time its the camshaft. The Adrino controlled indexer made quick work of cutting the cam lobes. To form the apex of the lobes I made a custom cutter. Filing and polishing took about as much time as the machining.
> 
> Next I think will be the cylinders. The plan calls for aluminum jackets but I plan on using steel to allow for some fabrication of the part.
> 
> ...


Fantastic nice work enjoyed your detailed descriptions, keep up the fine work


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## dnalot (Jan 10, 2020)

Thanks for the comments, much appreciated. 

Mark T


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## gbritnell (Jan 10, 2020)

Hi Mark,
The cam looks great. I have always made my cams and lifters as you said, drill rod cam (unhardened) and drill rod lifters (hardened and polished) and have never had any problems. You said that you were going to make your cylinder jackets from steel for some fabrication. If you could explain?
gbritnell


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## dnalot (Jan 10, 2020)

gbritnell said:


> You said that you were going to make your cylinder jackets from steel for some fabrication. If you could explain?



Hi George

It looks to me that using steel would allow me to silver solder the square flange to the jacket and soft solder the ports for the cooling water. It just seems like an easier way to do it. And I want to get away from the aluminum look. I like a variety of color and texture in my models. Using D.O.M. steel leaves very little machining of the barrel. And the steel will look nice with a "Plum Brown gun finish" don't you think. 

Mark T


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## gbritnell (Jan 10, 2020)

I do agree it will give it more of an authentic look. Th original castings were iron with iron sleeves. Bluing or anodizing would really set them off.
gbritnell


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## G54AUST (Jan 10, 2020)

G'day Mark   (et al).

I too have purchased Georges' brilliant drawing with a view to constructing this engine and shall be watching this thread with keen interest.

I too have purchased "Hollow Bar" to make the cylinder jackets.   Plan is to rough turn the OD and pilot bore the jackets,  silver solder the square base and the water in/out ports,  stress relieve and finish turn the ID and ends.   Liners to be made out of grade 3D cast iron.   All sealed with O rings.   Unfortunately,  blueing or black oxiding won't cover the silver solder so shall coat with epoxy paint.

Am currently redrawing this engine in metric but shall be constructing it 25 % larger.   All dimensions multiplied by 31.75 (25.4 by 1.25) to get to 125%.   ie.  bore is 1" by 31.75 = 31.75 bore;   rounded up to 32.   32 by 40 shall give me approx. 128cc capacity.    Oversized water pump and water pipes for additional cooling.   Radiator,  probably a computer radiator with brass outer cover.

Manual CNC here as well.   Gathering info and bits & pieces for CNC retrofit on my Mill.   HM52/G0757.

Enjoying your "MO".   _ (Modus Operandi)_


Kind Regards,

Trevor,
Melbourne, AU.


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## Lukas Pils (Jan 11, 2020)

Hi 

@ Trevor just a quick tip regarding imperial to metric conversions. If you multiply by 32 you get a slightly larger part but all dimensions have max. one decimal place ==> makes the drawing and machining easier. 

Kind regards,
Lukas


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## dnalot (Jan 11, 2020)

G54AUST, looking forward to following your build. If your gathering materials you must be about to get started.

Mark T


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## G54AUST (Jan 11, 2020)

G'day Guys.

@ Lukas Pils.     Fully understand what you mean Lukas,  and I do tend to round off as much as possible.   Mainly for stock sizing etc.   Having said that,   I am constantly working in plus/minus dimensions anyway.

@ dnalot.   Mark,   I'm rapidly approaching retirement so I'm amassing projects to keep the dark grey matter churning.   My Wednesday TTR job _(transition to retirement)_ is maintaining three steam locos on a private 7 1/4" gauge railway close to home.   I intend to use the Holt 75 _(plus 25%)_ in another project there.

You stated that this wasn't going to be a "step by step" build,  but members following this thread may just be hanging on to every post you make.   Many lurkers will be watching with keen interest but won't chime in.   Please keep up you detailed posts …..


Kind Regards,

Trevor,
Melbourne,  AU


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## mirek111 (Jan 11, 2020)

Very nice and demanding work.


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## dnalot (Jan 18, 2020)

So here are the cylinder jackets made from steel. I started with cutting the flanges as a group. And then cut the barrels from D.O.M. Steel. Very little material had to be removed so they were quickly turned to size. Now some steel cuts very nice, this steel is not one of those. Never found a way to cut it with a smooth surface so I had to sand it.


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## dnalot (Jan 18, 2020)

I cut a slight shoulder in the skirt to hold the flange in the correct place for soldering. I cut the shoulder to fit the flange snugly to prevent distortion from the heat and then filed a bit of a taper to to it to allow the solder to wick in. And to prevent the solder form getting on the wrong surfaces I used some wite out.


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## dnalot (Jan 18, 2020)

Using a Lazy Susan I rotated the part to heat it evenly. I love to silver solder. It is easy once you get the hang of it. Everyone knows you need to have clean surfaces, but most people forget to clean the oxide off the solder with some steel wool. Makes a big difference in getting it to start to flow. And most people use way to much flux.


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## dnalot (Jan 18, 2020)

After cooling the part was returned to the lathe to face off the flange. And then I sanded the surfaces clean.


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## dnalot (Jan 18, 2020)

Next step was to cut the pockets for the cooling water ports.


----------



## dnalot (Jan 18, 2020)

I then cut the blanks for the flanges as a group on the lathe. Next I cut the flanges to shape on the indexer.


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## dnalot (Jan 18, 2020)

And then the flanges were sanded smooth and parted off one by one. The small fanged ports were soldered to the jacket with solder paste. Wite Out was used again to control the solder.


----------



## dnalot (Jan 18, 2020)

After soldering, the flanges were drilled through the jacket wall and the holes for mounting hardware were drilled and taped. And then the flanges were faced. The final step was cleaning the parts and treating with a gun browning solution. Now that gives the jackets a nice sweaty look. I plan to age all the cast iron and brass parts on this model.










I think they look nice, but we all have different tastes. So now its time to cut some cylinder liners from cast iron. Thanks for watching 

Mark T


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## michelko (Jan 18, 2020)

Awesome . Keep on Posting. 
Someday i will Start my own build. 

Michael


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## CFLBob (Jan 19, 2020)

Agreed - awesome work.


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## dnalot (Jan 20, 2020)

Hi

Thanks for the comments guys. 

Mark


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## gmac (Jan 20, 2020)

Hi Mark;
Following along with the build and learning! Great work. What browning solution did you use ? How was it to work with? I like the look.
cheers Garry


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## dnalot (Jan 20, 2020)

gmac said:


> What browning solution did you use ? How was it to work with? I like the look.



I used Birchwood Casey Plum Brown barrel finish. This is not the easiest to use. It is a hot browning solution. The part temp should be around 275 degrees and very very clean. It usually takes several applications to get the darkness you want. My jackets were sandblasted, polished metal will brown more evenly. And submerging the part in the solution is best but is rarely practical. I applied the solution with a cotton swab that I held with chop sticks to avoid burning my fingers. Keep applying the solution until the part has cooled.  After browning let the part sit overnight before washing the solution off with hot soapy water and then burnish with a soft cloth. Then rub on some light oil mixed with a little lanolin. 

Mark T


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## gmac (Jan 22, 2020)

Thanks Mark! I know of that product but have no experience with it. You don't see it on the shelves in this neck of the woods so I never went any farther with it. Time to look harder!
Thanks again
Garry


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## Robert Ritchie (Jan 23, 2020)

dnalot said:


> After soldering, the flanges were drilled through the jacket wall and the holes for mounting hardware were drilled and taped. And then the flanges were faced. The final step was cleaning the parts and treating with a gun browning solution. Now that gives the jackets a nice sweaty look. I plan to age all the cast iron and brass parts on this model.
> 
> 
> View attachment 113447
> ...


Fantastic Work


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## Robert Ritchie (Jan 23, 2020)

I just viewed your post pictures, great work, enjoy following your projects.


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## FKreider (Jan 25, 2020)

Outstanding work!


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## dnalot (Jan 27, 2020)

The cylinder sleeves are made of cast iron. I started with a piece 1.25” by 12” and using my lathe I removed more that 95 percent of the material to find my sleeves. With a 1 inch bore and .063” wall the sleeves are fragile. The plan called for a press fit into the cylinder jacket but I chose to make them a slip fit and glued the sleeves to the jacket with loctite 680.


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## dnalot (Jan 27, 2020)

I cut the OD on the lathe and drilled out the center to ¾ of an inch before parting off. The parts were then held in a collet chuck for cutting the bore to size. I used a tool with a bit of radius, at my slowest feed rate to cut the bore. The tooling marks are not deep but it will take some work to smooth the bore.


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## dnalot (Jan 27, 2020)

For the next steps I turned down a mandrel to a close slip fit for the cylinder assembly. Using the mandrel I cut a chamfer at the bottom end to ease installing the piston with rings. And then I reversed the part and faced the assembly.


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## dnalot (Jan 27, 2020)

To drill and tap for the head bolts I mounted the cylinders to the top half of the block to make it easy to mount on the mill. From there I gave the bores a preliminary honing with a ball type hone to take the sharp edge off the top of the cylinder and to smooth the chamfer at the bottom. I still need to hone the cylinders with a precision finish cylinder hone but I need new stones for my tool and I'm waiting for them to arrive.


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## Robert Ritchie (Jan 27, 2020)

Enjoy viewing your build, very nice work.  Detailed description was great, thank you for your post I enjoyed viewing your fine workmanship.


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## dnalot (Feb 8, 2020)

On to the heads. I used the lathe to remove as much material as possible. Next I drilled the holes for the head bolts and roughed out the shape. The plans have the head bolts crowding the edge of the head. That bothered me so I am making the heads a tad bit larger.


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## dnalot (Feb 8, 2020)

Next I mounted the heads to the rotary table and cut the outer surfaces to size. I then mounted the heads to the cylinders and faced all the heads as a group to insure the manifolds will have a flat surface to mount up to. And then back to the rotary table to cut the details on the top surface.


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## dnalot (Feb 8, 2020)

After shaping the parts I drilled and tapped for the spark plugs and drilled the holes for the valves. And then some sanding and filing to remove any tool marks before sandblasting the parts prior to darkening the cast iron with a gun blue solution.













I would like to take a moment and thank all that have been following the build. And a special thanks to those that have left a comment. 

Mark T


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## gbritnell (Feb 9, 2020)

Hi Mark,
Did you have any particular trouble getting the ports to line up with the valve pockets? It's a tight fit between the head bolts. I adjusted the dimensions as much as possible to provide room and not break into the head bolt holes. 
gbritnell


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## dnalot (Feb 9, 2020)

Hi

No George, I had no problems there but it was a tight squeeze made a bit tighter by me. I drilled the holes slightly larger to make it easier to install the heads over studs.  So far your drawings have been spot on, very well done.

Mark T


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## Oldiron (Feb 9, 2020)

Did you use a bluing solution on the heads or the same browning solution as on the cylinders? It's hard to tell if there's a contrast in the last picture. Bob


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## dnalot (Feb 9, 2020)

Oldiron said:


> Did you use a bluing solution on the heads or the same browning solution as on the cylinders? It's hard to tell if there's a contrast in the last picture



I used a cold bluing solution Bob. It gives steel a blue color but on cast iron it is more black with a tinge of brown. I will be using it on the push-rods when the time comes. 

Mark


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## dnalot (Feb 9, 2020)

Oldiron said:


> Did you use a bluing solution on the heads or the same browning solution as on the cylinders? It's hard to tell if there's a contrast in the last picture



Here is a photo that shows the contrast a bit better. The parts are rather dusty as machining cast iron is dirty and the dust sticks to everything.


----------



## johnmcc69 (Feb 10, 2020)

I really like that finish, it gives it that old, weathered, patina.

 Real nice work all around Mark!

 John


----------



## Robert Ritchie (Feb 10, 2020)

Nice work, enjoying your posts , keep on building!


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## dnalot (Feb 25, 2020)

Time to make some valves. Now there's more than one way to skin a cat, this is how I do it.


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## dnalot (Feb 25, 2020)

I have made my valves with drill rod stems and stainless heads. The stems are cut to length and one end is tapered to allow the silver solder some room to wick in. The heads are roughed out with the fillet detail cut but not the valve face. And then using a fixture to hold the parts square and aligned to the stem the two parts are silver soldered together and allowed to cool in the fixture. From there they go to the lathe to be faced and to have the valve face cut to 45 degrees. Now the hard part, drilling a .030” hole through the .094” stem for the keeper pin. To make it easy to get the hole perfectly centered I made a simple jig. It was hard drilling and I went through 3 bits drilling through the 8 tool steel stems. 250 RPM worked best.


----------



## dnalot (Feb 25, 2020)

The valve guides were simple parts turned on the lathe. They were a light press fit but I used a little loctite to ensure there were no leaks.

The seats were cut with a 90 degree end mill. To find the center of the hole I used a precision point and moved the mill's table around until I could see the point was touching the hole on all sides. And then the end mill was used to cut the seat.

I used four grades of lapping compound from 320 grit to 600 grit. And for rotating the valve during the lapping I used a Pin-vice. As a final steep the valves were pressure tested in a fixture.


----------



## dnalot (Feb 25, 2020)

Now back to the cat. That's Andy, my feral shop cat after rooting out a Weasel. They are his favorite game because they fight back. Yes he bites and he will kick the **** out of your dog. A total bastard of a cat with catatude. But we are pals and I love him. Nothing wrong with his eye, just catching the light wrong.


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## Robert Ritchie (Feb 26, 2020)

Been waiting for your new post on valves and ect., well worth the wait very detailed post keep up the fantastic work!


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## dnalot (Mar 6, 2020)

The Con Rods are made from Bearing Bronze. The first step was facing the ends of the rod and cap before threading for the end cap screws. Once the end cap was screwed in place I cut the stock material down to the proper dimensions. And the the holes were drilled and reamed. Next using a fixture I cut the side profiles. From there I used my turntable to face the rod down to thickness. And then using my fixture again I cut the smaller details. After that a bit of filing and sanding before sandblasting the parts. The rods fit a bit snug on the crankshaft and will require a bit of lapping with a fine compound.










































So up until now I have been using a .7 to .9 Mbps web connection. Fiber optic cable finally reached my cabin and I now have a 80 Mbps connection. WOW, now I can upload my posts in a single go.

Mark T


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## kuhncw (Mar 6, 2020)

Nice work,Mark.

Chuck


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## bobden72 (Mar 7, 2020)

Very nice


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## Robert Ritchie (Mar 10, 2020)

Your engine is  coming together nicely, I enjoy viewing your post, great detail on post.


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## dnalot (Mar 21, 2020)

This post will cover piston rings. My past experience with making rings ended with marginal at best rings. This time I am using the “Trimble Method” and had much better results. I need 12 rings so I made 20 expecting some to be better than others. In the end I had 8 perfect rings and 6 more that required some finessing to make usable. The rest are just (s)crap.

The ring blanks were cut from fine grained cast iron. Once made the rings were honed on both sides to the desired thickness. To snap the opening in the rings I used a sharp chisel mounted in my mills chuck. That worked very well and the breaks were clean and straight.

From there the rings were mounted in the fixture and the face of the rings were covered with several wraps of paper. The fixture was then placed in a crucible with a bit of scrap pipe around it. To help keep air away from the surface of the rings I packed the fixture with a very fine “olivine sand” leaving just the top of the fixture exposed for taking temperature readings while heating in the furnace.

I used my propane foundry furnace to heat the fixture slowly to 1150 degrees and then held that temp for an hour. And then I turned off the furnace, covered the opening in the top with a fire brick and let it sit till it cooled (16 hours)

When I took the fixture out of the sand there was a powdery dust covering the face of the rings (from the paper). That dusted of easily leaving rings with a little soot but no real scale. The rings were stuck together and I needed to use a razor blade to separate them.

After cleaning the soot from the rings I filed the ends to set the gap and then tested each one in a cylinder to see if I could see light between the cylinder wall and the ring. I ended up with two extra rings.

So the next step is to make the pistons and after that I will be assembling everything I have made so far.

Mark T


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## awake (Mar 21, 2020)

Very nicely described and illustrated - thanks!


----------



## Robert Ritchie (Mar 21, 2020)

Now that was cool, nice work , I'm awaiting your next detailed post very interesting.


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## cooksservices (Mar 22, 2020)

This is a very nice thread, very informative thank you for sharing. I will definitely be using some of your techniques.


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## John Antliff (Mar 22, 2020)

Can I ask that you describe the breaking with more detail e.g. how was the ring presented to the sharp edge of the chisel?


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## dnalot (Mar 22, 2020)

John Antliff said:


> Can I ask that you describe the breaking with more detail e.g. how was the ring presented to the sharp edge of the chisel?



In the photo showing the rings after snapping you see the rings sitting on the top of the vice's jaws. The chisel is mounted in the chuck used for drilling. To snap the ring I placed the ring over the dimple you see under the chisel and then using the quill feeding handle I brought the chisel down on the ring with light pressure until it snapped. The dimple is optional, the ring will snap without it but will take a little more pressure.

Mark


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## John Antliff (Mar 22, 2020)

Thanks Mark, I wondered if you held the ring in the vice and brought the chisel down onto it which would seem to me risky.  The dimple would localise the stress and be a much more safe way of doing it.


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## kvom (Mar 23, 2020)

I assume you used a ball endmill for the rounding on the  big end of the rods.


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## gbritnell (Mar 23, 2020)

Hi Mark,
That is the same process that I have been using for years to make piston rings. I have tried other but always go back to the Trimble method. Great documentation!
gbritnell


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## dnalot (Mar 23, 2020)

kvom said:


> I assume you used a ball endmill for the rounding on the big end of the rods



Yes, I used a ball end-mill on the big end. 

Mark


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## dnalot (Mar 23, 2020)

Thanks for the comments, and the likes. 

Mark T


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## dnalot (Mar 28, 2020)

Some simple parts here but very necessary. The pistons are made off aluminum and were turned as a group. After turning they were drilled for the small end of the connecting rod and a small flat was cut where the hole went through the piston.

After parting off the pistons were faced top and bottom. From there they went to the mill to be hollowed out.

The wrist pins are made from drill rod. I used a brass rivet to provide a soft end to the pins.

And then one by one I assembled the con rods with pistons attached to the crankshaft (No rings) and installed the cylinder. And then the crankshaft was rotated to check for binding and clearance. All was good.

At this point I will go back and give each part of the engine a final fitting and detail before assembling the parts with gaskets and sealants. This needs to be done before I can make and fit the rocker arms and push rods.

Mark T


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## kuhncw (Mar 28, 2020)

I've never thought of making pistons that way.  Interesting. 

Great build thread.

Regards, 
Chuck


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## awake (Mar 28, 2020)

Nicely done! I like the ganged approach.

What are you using to hold the rivets in the wrist pin?


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## dnalot (Mar 29, 2020)

awake said:


> What are you using to hold the rivets in the wrist pin?


 680 locktite


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## kuhncw (Mar 29, 2020)

Mark,  I noticed how you are using the flats on the pinbore sides of the piston, along with matching pieces of metal to align the piston for milling the undercrown.  I'll try to remember that trick. Thanks.

Chuck


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## Robert Ritchie (Apr 5, 2020)

dnalot said:


> Some simple parts here but very necessary. The pistons are made off aluminum and were turned as a group. After turning they were drilled for the small end of the connecting rod and a small flat was cut where the hole went through the piston.
> 
> After parting off the pistons were faced top and bottom. From there they went to the mill to be hollowed out.
> 
> ...


Excellent work Dnalot,  great detailed posting, can't wait to see her run!


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## SPOTTER (Apr 6, 2020)

Great job, I ask you, why do you have to do the piston rings heat treatment?
thanks


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## dnalot (Apr 7, 2020)

The rings are machined to match the size of the cylinders bore. They are then split and expanded over a mandrel. The heat treatment causes the ring to take a set at the expanded shape. Once done the rings will be larger than the bore and will be springy. When installed in the bore the rings will press against the sides of the cylinder's walls making a seal. 

Mark T


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## dnalot (Apr 7, 2020)

Time to assemble what we have made, starting with the camshaft. The three center bearings are slit type with a bit of copper wire holding the halves in place. Once in position a screw locks the bearings in place. The end bearings are a very light press fit and are tapped in place with a soft face mallet.

Before installing the crankshaft in the case the rods were lapped with a 400 grit compound until the rods turned smoothly on the crankshaft.

Now the risky step, installing the rings to the pistons. I stretched the bottom most ring over the well oiled piston from the bottom. I then used a cylinder to push the ring up the piston to the bottom ring groove. The top two rings were then stretched over the piston from the top one at a time. Happy to report no rings were damaged.

The pistons were then mounted to the rods. And then the pistons were installed into the cylinders. I had chamferd the bottom of the cylinder's skirt and the rings were easily compressed allowing the pistons to slide into the well oiled cylinders.

And then one by one the cylinder with piston and rod were assembled to the crankcase. And then one by one the heads were installed. I used a “Portrait Cutter” to make the gaskets. If your not using one of these your really missing out.

The joining of the case halves and installation of the crankshaft end bearings completed the main assembly. To seal the case halves I use “Honda bond 4”.  Honda uses it to seal close fitting parts on their outboard motors. Brush it on as thin as you can, it is a latex like material when cured. As long as you burp any air out of the tube after use it will last a very long time.

I then installed the gear boxes and made a skid out of some Hickory wood. The wood was finished with a “wipe-on Polly”

Everything went together nicely and after giving the crank a spin with a drill motor I have compression on all cylinders. Number 3 cylinder may be a bit lower than the rest but not by much. I will need to wait until the valves are moving to give a proper compression check. 

I live in Washington State, one of the first places in the US to see the Corona bug flare up. We have been in lock-down for over a month now. So my next step on this project depends on what materials I have on hand. I would like to do the rockers and push rods next but may need to move on and do the flywheels.

Thank you all for watching. 

Mark T


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## kuhncw (Apr 7, 2020)

Excellent work, Mark!

I really enjoy your thread.

Regards, 
Chuck


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## johnmcc69 (Apr 7, 2020)

Wow! That looks GREAT!

 John


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## Sloboat (Apr 7, 2020)

Mark, your thread and postings, as well as your project are beautiful.... very nice.... I thought I would just post a photo I took this last Fall.  Your model makes this old hulk look sooooo pathetic... sitting out for at least 40 years.


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## dnalot (Apr 8, 2020)

Sloboat said:


> I thought I would just post a photo I took this last Fall. Your model makes this old hulk look sooooo pathetic... sitting out for at least 40 years.



Pathetic it may be but I think its beautiful.


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## awake (Apr 8, 2020)

Magnificent! Can't wait to hear it run!


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## Robert Ritchie (Apr 8, 2020)

Wow, nice job,  enjoyed reading your descriptions of the tasks you have done on the Holt 75.  Can't wait to see her purr, keep up the fantastic work!


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## peter2uat (Apr 9, 2020)

now I know where the Minions come from


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## dnalot (Apr 9, 2020)

peter2uat said:


> now I know where the Minions come from



I had to Google Minions. Now I get it.


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## kuhncw (Apr 12, 2020)

Mark, would you please tell us a little about the portrait cutter you use to cut gaskets.

Thanks.

Chuck


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## dnalot (Apr 12, 2020)

kuhncw said:


> Mark, would you please tell us a little about the portrait cutter you use to cut gaskets.



Here is a link for the cutter on Amazon. https://www.amazon.com/Silhouette-America-Portrait-2/dp/B009GZUPFA/ref=sr_1_1?crid=BFNKV1GT22Y7&dchild=1&keywords=portrait+cutting+machine&qid=1586745838&sprefix=portrait+cu,aps,236&sr=8-1

It does an incredible job cutting gaskets, patterns or decals. Even tiny holes come out perfect.

To avoid using their drafting tool I use my drafting program and draw my gaskets and then draw a box around them. Save the file.  I then load the portrait program and import the saved file to the Portrait library, and then load that file. The scale will be wrong. To correct that select everything including the box and then use the tool for scaling. Then adjust the size to match that of the box you originally drew. Its very easy to get the precise size you want.

For paper stock I usually use the "card stock" setting

Mark


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## cooksservices (Apr 13, 2020)

It looks like we are both progressing at a similar rate with our engines but the quality of work you are producing is something I aspire to! Thank you for sharing. 
I am very interested in the process you use for making gaskets, I have a silhouette cameo. I think this also can be used to cut card and other craft type materials. What thickness is your gasket material and is it actual gasket making material or something else that you have found suitable? 
Thanks, Sam.


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## dnalot (Apr 13, 2020)

cooksservices said:


> I am very interested in the process you use for making gaskets, I have a silhouette cameo. I think this also can be used to cut card and other craft type materials. What thickness is your gasket material and is it actual gasket making material or something else that you have found suitable?



I have used a variety of paper gasket material. Most often I use a paper of .015" thickness but have cut heavier material.

Mark T


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## kuhncw (Apr 13, 2020)

Mark,  thanks for the detail on your portrait cutter and materials.

Chuck


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## Rustkolector (Apr 13, 2020)

Mark,
Do you think your gasket cutter would work with .015" Teflon gasket material?
Jeff


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## dnalot (Apr 13, 2020)

Rustkolector said:


> Do you think your gasket cutter would work with .015" Teflon gasket material



I don't know if it would stick to the cutting mat. I don't have any Teflon to try. I think the blade would cut the material just fine if it could be made to stick to the mat. 

How do they get Teflon to stick to the pan?

Mark T


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## dnalot (Apr 20, 2020)

OK time for rockers, Rock on.

I didn't have any material for making the rockers from one piece,  so I fabricated them. The body or web is brass and the cone and hinge point were made from Bronze. These parts were then silver brazed together. To align the parts during the soldering I cut a notch in the cone and turned the hinge with a grove in the center. The end of the rocker that contacts the valve stem was fitted with a bit of drill rod soldered in place with Stay-Brite silver solder (low Temp) and then filed to shape. Once made the rockers were dipped in a solution to give them an aged look. The bit of steel caused some interesting colors to form on the parts. I liked the look so I left them that way.

Mark T


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## dnalot (Apr 20, 2020)

The push-rods and lifters were made from material I thought was tool steel.  When tempered they were only marginally hardened. So I case hardened the ends of the rods and the entire lifter. After that a file would only skip across the surface. After that the parts were polished and then I put a Gun-blue  finish on the rods. The hardened ends of the rods would not take the blue. Again I liked the look so I left the rods as they were. After assembly I rotated the cam and everything worked and turned smoothly. At this point I have set the rocker's gap at .005”. Does anyone have any recommendations for the proper gap?

Mark T


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## awake (Apr 20, 2020)

Beautiful work!


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## Robert Ritchie (Apr 23, 2020)

I enjoyed your new posts, your work is fantastic, very detailed workmanship.   Will be awaiting next post!


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## johnmcc69 (Apr 23, 2020)

Natural color/finish of materials is fine, but I really like the treatment you've given these parts. I think it looks fantastic!
 Keep up the great work, really looking forward to seeing it run.
-curious how well the finish will hold out...it might get better...

 John


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## CFLBob (Apr 23, 2020)

+1 to johnmcc69 - the colors and look of the engine's finish is fantastic.  I'm watching every update.


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## dnalot (Apr 24, 2020)

Thanks for the comments and "likes" guys. It motivates me to work harder. And a shout-out to Mr George Britnell for his excellent set of drawings. 

Mark T


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## G54AUST (Apr 25, 2020)

Still loving your work Mark.   Keep going strong Mate.   So glad you have covered the build in such detail.

(Would be interesting to see how many "views" this build has clocked up.   Angie,  does the forum have a counter ???)

And yes,  you are correct,  in ref to Georges drawings.   An absolute pleasure to peruse.



Kind Regards,

Trevor,
Melbourne,  AU.


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## dnalot (Apr 25, 2020)

G54AUST said:


> (Would be interesting to see how many "views" this build has clocked up. Angie, does the forum have a counter ???



Yes there is a counter, 18000 + views for this build. If you look at the "A work in progress" page you will see the count on the right of the listed threads. Some may have noticed I have slowed down. I tore a ligament in my right thumb about 6 weeks ago and have been working one handed since. Unfortunately my left hand is not very talented and is all thumbs.  

Mark T


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## awake (Apr 26, 2020)

Ouch! I hope your thumb is recovering!


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## cooksservices (Apr 26, 2020)

Incredible attention to detail, the finish on your parts looks amazing. This has definitely given me a standard to aim for.  Thank you for sharing!


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## dnalot (Apr 28, 2020)

I present here something perhaps a little unexpected. On the old “Cole casting kit” the crankcase side covers had the Holt name in the casting. A nice touch but the font was wrong. On the scratch built engines I have seen photos of, the name was eliminated. I have made my covers with the “Holt” name on them in a font that is much closer to realistic. On some old photos all 4 covers had the name cast in, on others only one cover per side had the name.

All made of aluminum and sandblasted to give a cast look. The letters were cut out on the mill and then epoxied to the cover before sandblasting. After sandblasting the letters were sanded smooth. (Mounted temporarily with cap screw) I hope you like the look.

Mark T


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## dnalot (Apr 28, 2020)

Thanks for your comments guys. And thanks to those just watching 

Mark T


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## gbritnell (Apr 29, 2020)

Great detail touch Mark! At the time I built mine I thought about it but just never did it. When I built the radiator I drew the logo up in CAD and cut it right into the top tang with a .031 end mill. Kind of like manual CNCing.
gbritnell


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## Foketry (Apr 29, 2020)

great and nice job , if you want, I also drew the  logo for  radiator


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## dnalot (Apr 29, 2020)

Thanks George, Foketry for your input. .031 end mill, now that's a small bit. I will be doing something for the radiator but have not looked ahead that far. Next I think will be the flywheels because I have the material on hand. 

Mark T


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## kvom (Apr 29, 2020)

If you're using CNC, why not mill the letters and cover as one piece?  The result looks great regardless of method.  I need a bead blast setup.


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## dnalot (Apr 29, 2020)

kvom said:


> If you're using CNC, why not mill the letters and cover as one piece? The result looks great regardless of method. I need a bead blast setup.



That's my problem, I'm not using a CNC, wish I were. I have a cnc router but the spindle speed is 10,000 to 30,000 RPM. Aluminum melts at that speed and grabs the cutter. And yes you do want a sand blaster, not everything needs to be shinny.


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## CFLBob (Apr 30, 2020)

dnalot said:


> That's my problem, I'm not using a CNC, wish I were.


If I may plant a thought - the project of converting a manual mill to CNC is an interesting project itself.  However, the First Law of just about everything in the universe applies, "there's no such thing as something for nothing."  Jobs like the letters get easier, simple jobs like hogging out the four quadrants of the cover or cutting it to size can end up taking more time.  Some jobs, like carving intricate stuff in metal, are about impossible without CNC.  Those don't show up here because we're a Model Engine Makers' forum, not an everything forum.


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## Robert Ritchie (May 4, 2020)

Once again you amaze me, really enjoy your work!


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## Robert Ritchie (May 5, 2020)

Nice work Dnalot, enjoyed your post


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## dnalot (May 9, 2020)

This time its flywheels, made from cast iron.

Fairly straight forward, turn on the lathe and then move to the mill to cut the spoke detail. I used a four jaw chuck to rough out the wheels. Then they were mounted to a mandrel with a key way. The final cuts were made truing up the wheel and reducing it to its final size and form. On the mill I removed the majority of material using a plunge cut and then ran the bit full depth along the cut line to smooth things up a bit. On the larger wheel I used a radius cutter to soften the edges and add a little detail.

After a little filing the center of the wheels were sandblasted  and the outer rim was sanded smooth.

A little dip in a bucket with Parkerizing solution turned the wheels nice and dark. A little light oil dressing and the wheels are done.


Mark T


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## dnalot (May 9, 2020)

Thanks your your comments. Thinking I will tackle the headers next. 

Mark T


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## johnmcc69 (May 9, 2020)

Wow! That looks GREAT! Fantastic work.

 John


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## Robert Ritchie (May 9, 2020)

Once again you've amazed me with your flywheel work!  Looks so sweet mounted on your motor, full speed ahead nice job.


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## CFLBob (May 9, 2020)

I love the wood screws holding the work onto a table-saving fixture.  I've got to copy that!  

I've been using a 1/2" (thick) aluminum plate and tapping new #10-32 holes to mount things.


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## gbritnell (May 10, 2020)

Very nicely done on the flywheels! Starting to look quite impressive!
gbritnell


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## dnalot (May 20, 2020)

A little update on my progress. Working one handed is slowing me way down. I am wearing a fiberglass splint on my right hand to immobilize my thumb. My fingers work so I can still spin the hand-wheels on my lathe and mill.

I am trying to reproduce the look of the original engines manifolds as best I can. Here I am showing how I am going about the exhaust manifold. The photos show my step by step progress and are pretty much self explanatory, but if you have questions just ask. I'm missing a photo of the two halves being silver soldered together. I cut the outline of one half and kept the other half a rectangle for soldering to maintain rigidity.

Once the intake manifold is completed I will need to make some adjustments to fit them to the engine. And then I plan to sandblast them before nickle plating the parts. I am hoping after some running time the exhaust manifold will get some color from the heat.

Mark T


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## dnalot (May 20, 2020)

On to the intake manifold, thanks for watching. 

Mark T


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## CFLBob (May 20, 2020)

As always, awesome work.  

One question: how do you get from the third to last picture (with the calipers) to the next one: sand blasting?


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## kuhncw (May 20, 2020)

Very well done, Mark.  Thanks for posting th9.

Chuck


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## dnalot (May 20, 2020)

CFLBob said:


> One question: how do you get from the third to last picture (with the calipers) to the next one: sand blasting?



I used a Dremel with a small drum sander and a small pad sander attachment, then sandblasted. It didn't take very long but I was covered in fine brass dust. It is still a bit rough, I plan to detail it a bit better after I get the intake manifold made. 

Mark


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## H Pearce (May 20, 2020)

Very impressive manifold.




dnalot said:


> View attachment 116473
> 
> View attachment 116474
> 
> ...


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## johnmcc69 (May 20, 2020)

Great work Mark!
 What? No casting flash on the parting lines? 

 John


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## Peter Twissell (May 21, 2020)

Nice Job!
Was the milling done by CNC or hand twiddling to follow marked lines?


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## gbritnell (May 21, 2020)

Hi Mark
When I made the drawings I drew the manifolds whereas a somewhat skilled machinist/builder could make them and still have them look acceptable. What you have done is what I would do but a lot of fellows don't have the ability or patience to carve shaped parts (manifolds) from solid. 
I have been asked many times if I ever made drawings for the 302 V-8 engine and my answer was no. Not that I can't make them but to replicate the casting details would take three times as many drawings to show the shapes and how to develop them. 
gbritnell


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## bobden72 (May 21, 2020)

Very good piece of work I love it and the end result is great.  How long did it take ?


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## dnalot (May 21, 2020)

Peter Twissell said:


> Was the milling done by CNC or hand twiddling to follow marked lines?



I twiddled and twiddled and twiddled

Mark T


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## dnalot (May 21, 2020)

bobden72 said:


> Very good piece of work I love it and the end result is great. How long did it take ?



I didn't keep track but probably around 16 hours spreed over many days. My injured hand slowed me down and keeps me from working more than a couple hours a day.

Mark T


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## dnalot (May 21, 2020)

gbritnell said:


> When I made the drawings I drew the manifolds whereas a somewhat skilled machinist/builder could make them and still have them look acceptable



I hear what your saying George. Your model is so nice I just thought it deserved the extra mile. And I wanted to show what can be done even if you don't have a cnc. It really wasn't difficult, just time consuming.  The biggest problem I had was finding the brass stock,  

Mark T


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## awake (May 21, 2020)

Wow! Impressive results, and hard to imagine doing this all by hand - especially singular hand!


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## Robert Ritchie (May 27, 2020)

Dnalot the one hand man, you amazed me again, great work, enjoy your project posts.


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## dnalot (May 31, 2020)

Finally got some time to work in the shop. Spent the weekend making the intake manifold. Basically just a repeat of the process to make the Exhaust manifold. I am waiting for some 3-48 threaded rod for the mounting studs and the chemical dip to darken the brass. I will update this post with a photo of the completed mounted manifolds soon as my materials arrive.

As always thanks to those of you watching this build (25k views) and to those that have left a response.  Nice to know your not playing to an empty house.

Mark T


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## Robert Ritchie (May 31, 2020)

Looking good,  enjoyed your post!


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## minh-thanh (Jun 1, 2020)

dnalot said:


> View attachment 116762
> 
> View attachment 116763
> 
> ...


A great job !


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## gbritnell (Jun 1, 2020)

Outstanding work on the manifolds Mark!


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## awake (Jun 1, 2020)

Indeed, I am impressed by your manifold talents. (Yes, pun intended - of course!)


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## Peter Twissell (Jun 1, 2020)

Seeing your work on those makes me want to make some manifolds, even though I have no reason to.


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## G54AUST (Jun 3, 2020)

G'day Mark,  et al.

     Good to know your back in the shop.   Any big celebrations mid last month ?????

     Noticed in post #155,  you've used shoulder bolts for the rocker pins,  very cluey.

     Attached are some pix of the shoulder bolts I'm using for a steam loco crosshead rebuild.   These are Dia 6 by M5 by 25 long.   I needed fitted bolts so modified some shoulder bolt to suit the need.   Might add some more bling to the heads on your Holt.














     Ironically,  the buff coloured envelope these are sitting on contains the Holt 75 drawings from George.


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## dnalot (Jun 3, 2020)

G54AUST said:


> Attached are some pix of the shoulder bolts I'm using for a steam loco crosshead rebuild. These are Dia 6 by M5 by 25 long. I needed fitted bolts so modified some shoulder bolt to suit the need. Might add some more bling to the heads on your Holt.



Yes, I like that.  And I will be doing as you suggest. I looks like you used a cutter with a slight radius. I will need to order a cutter like that or modify something I have. 



G54AUST said:


> Any big celebrations mid last month ?????




I can't recall anything going on in mid May unless your referring to my turning 70. This is my favorite card, it captures me perfectly.


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## G54AUST (Jun 3, 2020)

G'day Mark.

     Yes.   I used a 6mm carbide cutter with a .5 rad.   (Good eyes Mate)   Clocked up the collet holder on centre,  used the X axis both + & - (climb mill) and rotated the collet holder twice for all six sides.   Head dia is 10mm,  hex is 8mm AF.   X+7 then X-7 on return.   One pass.   Very quick and easy.   Prob 1 minute each.

     Yes.   70th.   Love the card …..


Regards,

Trevor,
Melbourne, AU.


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## Robert Ritchie (Jun 4, 2020)

70 is  a good speed , enjoyed your Birthday card!


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## dnalot (Jun 9, 2020)

With the machine work completed on the manifolds its time to put a finish on them. I started with nickle plating them The sandblasted surface gives a satin look to the plating but it's to bright. To fix that I dipped the manifolds in a gun bluing solution. The exhaust manifold I left in the dip a little longer than the intake, and then heated the manifold with a torch to give it somewhat of used look. 

I have been working on the radiator core. Will post a few photos latter this week. 

Mark T


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## Tim Wescott (Jun 9, 2020)

That is a nice job of aging the metal.


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## Robert Ritchie (Jun 9, 2020)

Looks great, like the finish.


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## dnalot (Jun 11, 2020)

Time to make a radiator. Starting with the tubes for the core. Having waited far too long for the half inch square stock to be shipped and delivered I decided to use hex stock instead. I only had an almost 36” length so I had to make them .2” shorter than the plan calls for. I will make up the difference with the lower tank. To make setting up for the cuts easy I opted for .1” spacing, .045” cut, .065”  thick fin. I drilled the hole through the part after turning the fins. Still needs to be cleaned up but that will have to wait until the tanks are soldered on.

Mark T


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## CFLBob (Jun 11, 2020)

That hex stock makes a surprisingly beautiful radiator!


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## Peter Twissell (Jun 11, 2020)

Very nice. I think the square section version would pale by comparison.


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## rpf (Jun 14, 2020)

That radiator is wonderful with hex!!
How about putting this engine on a lawnmower? I remember a pictures of a lawnmower with an Stuart Turner steam engine on it, the builder said he never had any problem getting the grandchildren to cut the grass for him!
Anyone else remember that? I cannot find anything about it now?


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## Robert Ritchie (Jun 16, 2020)

Fantastic,  great post,  nice job!


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## dnalot (Jun 16, 2020)

I would like to thank those that left comments on my last post. A appreciate it.
Mark T


The radiator tanks are easy to make parts. I made one change in that the radiator vent is drilled into the body of the top tank. The plan called for the vent to be a tube along the top of the tank on one side. I was able to cut the letters using my cnc router. The cutter was only .063 on diameter so the 10,000 rpm spindle was not a problem. After soldering the tanks to the core I checked for leaks and then clamped it up on the mill to square the sides. I had left about .010” of material for that on each side. I like to work with brass but I hate the look of bright brass. A few seconds in a brass aging solution darkens it up. I will probably take a bit of fine steel wool and give it some highlights before I'm done. The last photo make it look like the letters are painted white, they are actually polished brass.

Mark T


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## kuhncw (Jun 16, 2020)

Very well done, Mark.  By the way, I like the finish on your exhaust manifold.  It looks like it's run hundreds of hours under heavy load.

Chuck


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## dnalot (Jun 22, 2020)

The radiator is completed and mounted. I deviated from the plan with the mount and the fan shroud. The plan called for a number of parts made from aluminum. I have a good supply of brass scraps accumulated from years as a boat builder. So I made a simpler mount and shroud from brass soldered together as a single part.

Summer is here so I plan to sit in the sun and sip whiskey while I watch the deer eat my roses. Bound to cut into my shop time some. I think I will be making the water pump and water lines next.

Mark T


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## CFLBob (Jun 22, 2020)

Looking beautiful!  



dnalot said:


> Summer is here so I plan to sit in the sun and sip whiskey while I watch the deer eat my roses. Bound to cut into my shop time some.



I'm in Florida and it's exactly the opposite.  Time to lock myself indoors and spend more time in the shop.  All the critters around here, deer, turkey, hogs, all the fish, whatever, are more active at night.  Winter's our season for getting outdoors.


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## awake (Jun 23, 2020)

Mark, that is a work of art!


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## johnmcc69 (Jun 24, 2020)

Stunning work & part finish! Looks like a freshly serviced engine.

 John


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## Robert Ritchie (Jun 24, 2020)

Looking good,  great post, enjoyed your details, fine job.


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## dnalot (Jul 2, 2020)

While waiting for material for the water pump I have been making the water manifolds. I started by turning the flanges on the lathe. From there I moved them to my cnc router and cut the flanges to shape.  After that I drilled the screw holes in the flanges. And the last step was using the mill to cut the relief for the ferrule.

I used a high temp silver solder paste for mounting the ferrule to the flange. This was my first time using a paste, I think it will be my go-to for small parts from now on. I made a sheet metal shield to protect the engine while I soldered the assembly together. I drilled through the flange assembly into the tube as the last step.

To complete the cooling system I still need to build the water pump. I have bearings, some o-rings for the belt drive and a bit of aluminum on order.

Mark T


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## kuhncw (Jul 2, 2020)

Nice work.  Your soldering heat shield is an interesting idea.

Chuck


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## Robert Ritchie (Jul 2, 2020)

There you go again, hitting the target on the water manifold!  Thanks for the update post, full speed ahead.


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## dnalot (Jul 13, 2020)

The water pump is completed and mounted. I still need to make a water line to connect it to the radiator, and the pulleys that will drive the pump. I will make the pulleys when I make the pulleys for the fan.

Mark T


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## kvom (Jul 14, 2020)

Nice  job on the soldering.


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## Robert Ritchie (Jul 19, 2020)

As always great job!


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## dnalot (Jul 29, 2020)

With this post the cooling system is completed. I deviated from the plan a little in that the fan support legs were meant to be cut from a single piece of material. I didn't have a suitable piece of aluminum that size so I made my legs in two pieces and modified the bearing housing to accommodate that change. I also made the legs a bit heaver because I plan to mount the fuel tank to the fan support structure. The fan pulleys are a bit larger to accommodate the o-rings I had on hand.

For those following along and leaving a comment I thank you.

Next I will be starting the fuel system . Its summer here and I am not spending much time in the shop. The novelty of  nice weather will soon wear off and I will get back to it.

Mark T


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## CFLBob (Jul 29, 2020)

You, sir, are an artist.


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## dnalot (Jul 29, 2020)

CFLBob said:


> You, sir, are an artist.



I think you have me confused with my brother Ben, he is the artist of the family.


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## CFLBob (Jul 29, 2020)

He just works with a different medium and different tools.


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## awake (Jul 29, 2020)

Which one of those three is Ben??


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## Richard Hed (Jul 30, 2020)

dnalot said:


> I think you have me confused with my brother Ben, he is the artist of the family.
> 
> View attachment 118274


OMG, you are from the "Soviet"!  I grew up in Yelm, went to high school at Toutle Lake!  Am now in Moses Lake.

Both you and ur bro are artistes!  Good works.


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## dnalot (Jul 31, 2020)

Richard Hed said:


> OMG, you are from the "Soviet"! I grew up in Yelm, went to high school at Toutle Lake! Am now in Moses Lake



I don't know what you mean by the Soviet. Moses Lake, now that is a bleak place. What are you doing there, watching the 737 Max planes arrive for storage. A few years back I owned a 200 acre wild life preserve in the Moses Coulee. A nice place for rattle snakes to thrive. Every summer I hosted students from a variety of Collages to study snakes, badgers, bats and other critters. Sold the place to the "Nature Preserve", it was a sad day.

Mark T


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## dnalot (Jul 31, 2020)

awake said:


> Which one of those three is Ben??



Well he isn't much like a sea lion or a bear or a native american. He can be a bit of an ass so its probably the wales tail at the bottom. 

Mark T


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## Richard Hed (Jul 31, 2020)

dnalot said:


> I don't know what you mean by the Soviet. Moses Lake, now that is a bleak place. What are you doing there, watching the 737 Max planes arrive for storage. A few years back I owned a 200 acre wild life preserve in the Moses Coulee. A nice place for rattle snakes to thrive. Every summer I hosted students from a variety of Collages to study snakes, badgers, bats and other critters. Sold the place to the "Nature Preserve", it was a sad day.
> 
> Mark T


Washington is so liberal that it must be a soviet.  don't gets me wrong--I too am a liberal but just not one who believes in velvet gloved stalinism.


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## Robert Ritchie (Aug 2, 2020)

Full speed ahead Mark great work!


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## dnalot (Aug 19, 2020)

So here is the carburetor. Made from brass with a .031” dia. Sewing needle. Fussy little thing to make, tiny little drills and close fitting parts. After assembling I attached a fuel line and put the end of it in a cup of water to test it using an air hose to blow air through the venturi. A nice atomized mist of air indicates it is working. Finished the body off with nickle plating on a matte surface.

Next is the fuel tank and the sediment bowl.

Mark T


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## awake (Aug 19, 2020)

Very nice! What plans are you using for this carb?


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## dnalot (Aug 19, 2020)

awake said:


> Very nice! What plans are you using for this carb?



Hi Andy. It was included in the plan set for the Holt 75. The tricky part was  finding a .031" needle. I had to wait for my wife to leave the house so I could search her sewing room. It was kind of exhilarating risking my life like that. 

Mark


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## awake (Aug 19, 2020)

But the danger is not past. One of these days, she's going to be asking what happened to the needle that she KNOWS she had, right there ...


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## kvom (Aug 20, 2020)

Just take a .032" needle and turn it down.


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## Robert Ritchie (Aug 23, 2020)

great job mark!


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## dnalot (Aug 25, 2020)

I soldered the tank ends with silver solder and soft soldered everything else. The sediment bowl was cut from a glass test tube with a diamond wheel lubed with drops of water. After cutting the bowl's edge was smoothed with a diamond sharping stone. Before installing I filled the tank and checked everything for leaks.

Next I will be completing the fuel system with the governor and the linkage.


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## kuhncw (Aug 25, 2020)

dnalot said:


> I soldered the tank ends with silver solder and soft soldered everything else. The sediment bowl was cut from a glass test tube with a diamond wheel lubed with drops of water. After cutting the bowl's edge was smoothed with a diamond sharping stone. Before installing I filled the tank and checked everything for leaks.
> 
> Next I will be completing the fuel system with the governor and the linkage.
> 
> ...


Very nice work.  I really like the detail your sediment bowl adds.

Chuck


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## dnalot (Aug 25, 2020)

kuhncw said:


> I really like the detail your sediment bowl adds.
> 
> Chuck



Its actually   George Britnel's sediment bowl.  It was included in the plan set. Thanks for the comment.

Mark T


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## Tim Wescott (Aug 26, 2020)

I'm making needles for model airplane engines by chucking music wire into an electric drill and grinding in the taper on a bench grinder, followed by a polish on an oil stone.  So far it seems to work.

But I'm using 1/16" wire, not 1/32".  (And yes -- music wire.  Eventually I'll need to get serious and use proper drill rod).


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## dnalot (Aug 26, 2020)

Tim Wescott said:


> I'm making needles for model airplane engines by chucking music wire into an electric drill and grinding in the taper on a bench grinder, followed by a polish on an oil stone.  So far it seems to work.
> 
> But I'm using 1/16" wire, not 1/32".  (And yes -- music wire.  Eventually I'll need to get serious and use proper drill rod).



Look at using drill bits. Good steel and they come in all sizes. The problem i see in music wire is that it generally comes in coils so it isn't straight. 

Mark


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## stevehuckss396 (Aug 27, 2020)

I buy most of my music wire from McMaster Carr.  They have one foot pieces in 100 PC bundles for between 5 and 15 bucks depending on size. Perfectly straight but only 12 inches.


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## ozzie46 (Aug 27, 2020)

You can get 3 ft. straight lengths from places like Tower Hobbies that cater to the RC airplane crowd. I have some that is .024 and .032 and up, can't remember what the smallest size you could get is.

 Ron


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## Tim Wescott (Aug 28, 2020)

ozzie46 said:


> You can get 3 ft. straight lengths from places like Tower Hobbies that cater to the RC airplane crowd. I have some that is .024 and .032 and up, can't remember what the smallest size you could get is.
> 
> Ron



.008.

And I'm a member of that model airplane crowd (RC, CL, and FF).  So when I think "music wire" I think three-foot straight lengths of drawn carbon steel wire that seems to run a hair oversize from its nominal diameter.


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## Robert Ritchie (Sep 2, 2020)

Great progress, nice work Mark!


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## dnalot (Oct 20, 2020)

Hi

Well I had a great summer despite being in lock-down. Got out of the shop and out into the sun for a few weeks.  Its Fall now and its wet out so I got myself back into the shop to work on the Holt project. This update shows the governor and the linkages connecting it to the carburetor.

Next is balancing the flywheels and making a starter clutch.

Mark T


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## kuhncw (Oct 20, 2020)

Very nice work, Mark.  The parts look great.

Chuck


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## Robert Ritchie (Oct 20, 2020)

Looks great Mark, full speed ahead, I'm glad your back enjoying your shop and build!


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## dnalot (Oct 25, 2020)

Hi

First let me thank you guys that left messages or left “likes” on my last post. It is very appreciated.

In the past when I made a starter clutch I used a one way bearing that a rod chucked into a drill motor would turn. The rod was hard to keep square to the bearing and so the bearing would soon fail. This time I am doing things a little different. The result is a starter clutch with a bearing that will stay aligned and not as likely to fail.

The bearing is a press fit into the part with the nut machined on the end. The shaft the bearing rides on has been case hardened.  In the free turning direction the clutch turns butter smooth. In the drive direction the bearing locks up instantly. I think it looks nice.

Now I need to dissemble the engine a little to remove the front flywheel so that I can balance it and the rear flywheel as a unit. Before reassembly I will be timing the crank to the camshaft. And then it will be time to work on the distributor and ignition system.

Mark T


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## Robert Ritchie (Oct 26, 2020)

Nice Job Mark!


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## dnalot (Oct 27, 2020)

Hi, Thanks for following along. The end is near. Still have the ignition system to go and then the inevitable problems encountered when trying to start a new motor.  

No photos this time, you will have to use your imagination.

The flywheels have been balanced. Before putting them back on the engine I made a protractor and set the camshaft timing to the crankshaft. I set cylinder one to start opening the intake valve at 20 Degrees BTDC. I then installed the big flywheel and the starter clutch. And I installed the spark plugs. Using a drill motor I rolled the completed engine over for the first time. Defiantly have compression and it sounds like a motor should. I need to fallback now and do some pickup work like a larger pulley for the water pump, some hardware replacement and some gaskets. And I still need to put water in the radiator and check the system for leaks.

Some time this week I will receive material for the distributor. I purchased an ignition system from Roy Sholl over at the S/S web sight   Roy's CDI Ignition Systems   . He shipped it promptly but was out of stock on the distributor wire with boot so I will be waiting on those. Roy is no longer running his web site as a business, but he is continuing to build some of his systems. He answered my email request for availability and cost the next day. And he shipped a couple of days after I sent an email placing the order. He trusted me to send the check.

Mark T


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## Robert Ritchie (Oct 28, 2020)

At last the final chapter is coming soon, enjoyed your update!


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## Canyonman (Oct 28, 2020)

Love that Sediment Bowl!   Excellent Workmanship!!


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## JaamieG (Nov 4, 2020)

WOW excellent work! Impressive


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## gbritnell (Nov 15, 2020)

Hi Mark,
I'm really anxious to see your engine completed! Your work has been outstanding!  Of the drawing sets I've sold your's will be the first completed that I know of. As I sold the drawings I would get feedback about a missing dimension or feature that needed a little more explanation so the drawings were always in a state of updating. I'm very happy that you had good success using them. I have never had trouble with my one-way bearing setup but I like what you have done with yours. With your permission I could add your design idea to the drawing set.
gbritnell


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## dnalot (Nov 15, 2020)

gbritnell said:


> I have never had trouble with my one-way bearing setup but I like what you have done with yours. With your permission I could add your design idea to the drawing set.



Go for it George. Another small item to fix on your drawings is a set screw for the distributor mount.  While we are on the subject I have a question about the timing disk. The drawing calls out steel as the material. I am wondering if steel being magnetic is not the best choice in breaking the magnets field of flux. I plan to use aluminum.

I am plodding along on the last few parts that need to be made rather slowly. My wife is about to retire and she has me busy re configuring her work (hobby) room. I will be posting again in a week or so showing the the distributor system. After that a little pickup work before I try and start it. This is my second IC engine, my first being the Snow Engine. I never got the Snow to run well so I am being meticulous about getting everything just so on this engine. I would cross my fingers but arthritis makes that impossible. 

Mark T


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## gbritnell (Nov 15, 2020)

Hi Mark,
The disc should be made from steel. Here's why. When I got involved with Hall trigger ignitions the first disc I made was of brass. When I spun the distributor I got no spark. In my mind I thought that with the brass being non magnetic it should work just fine to block the flux from the magnet, it turns out that it was just the opposite, it needed the steel to absorb the magnetism so that when the timing window opened up it would fire the Hall transistor. I don't know the physics behind it I just know it works. Is there a reason why you wouldn't want to make it from steel?


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## dnalot (Nov 15, 2020)

gbritnell said:


> Is there a reason why you wouldn't want to make it from steel?



No, just over thinking the situation. Steel it is then. Is there a reason for the squared holes? would slots work as well? 

Mark


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## Canyonman (Nov 15, 2020)

Dude!!! That's Awesome!!   Ken


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## gbritnell (Nov 16, 2020)

Wow! Lovely job on your engine! I can't wait to hear it running. I like what you did with the manifolds.
Mark,
The idea behind the square timing slot was that it would possibly produce a sharper cut-off to the Hall. It might work just fine with round holes but I have never tried it. I have made 6 distributor type engines and have used the square slots in all of them.
gbritnell


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## ajoeiam (Nov 16, 2020)

JRR said:


> Hi George
> I finished the Holt 75 yesterday.Many thanks for a fine design although I did make a few changes as you will no doubt spot.After I fixed an air leak in the intake manifold it started straight away and ran well , responded well to the governor and had a lovely exaust sound.
> Thanks also to Mark for the one way start mechanism.
> Attached are some photos and I will attempt to do a video of it running soon .John



Very nice!!!!!!!


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## gbritnell (Nov 16, 2020)

Tol JRR, Mark and any others that purchased the drawings for the Holt. I just made a drawing of the rain cap that I have on my exhaust. It adds a little bling when it's running slow. The drawing is attached.
gbritnell


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## Steamchick (Nov 17, 2020)

A real museum showpiece! Excellent! Well done sir.
K2


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## teeleevs (Nov 17, 2020)

Wow a beautiful job, so pleased when it springs to life.


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## dnalot (Nov 17, 2020)

It has been a little over a year sense I started a build log on the Holt 75. I put a lot of effort into this log and I almost made it to the end before my thread was hijacked. Another member posted photos of his completed engine at the eleventh hour, I feel it would now be anti-climatic to post photos of my engine on this thread.  When completed and running I will post photos and a video on a new thread under the “completed projects” category.

Mark T


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## kuhncw (Nov 17, 2020)

Mark,  I really hate to see your completed engine separated from your meticulous build thread.
Can the moderators move the other member's posts and comments to a separate thread?

Chuck


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## gbritnell (Nov 17, 2020)

Hi Mark,
Don't take it personal. I don't think there was any malice in his posting he was just enthusiastic about presenting his work. I understand your feelings after all the work and documentation you have done. I for one can't wait to see it completed and running.
On another note, I replaced the rain cap drawing with another. I missed a dimension so I added it to the new drawing.
gbritnell


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## rpf (Nov 18, 2020)

Please carry on, Mark, it is hugely inspirational! even my 10 year old nephew thinks it is a very cool looking engine and is keeping track!!


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## Robert Ritchie (Nov 20, 2020)

Mark I've enjoyed your build from the start,  I was shocked when I read a post from a fellow project worker on your same project thread.  How does  this forum allow such a low level deed by an individual who new exactly what he was doing.  I'm requesting an response from the leader of this machinist site,  Mark deserves an answer, he has put forth hours of effort towards his engine build only to be out down by by an hijacked thread in which this forum has allowed!


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## Rdean33422 (Nov 20, 2020)

I have stopped posting in my thread as well for the very same reason as Mark did.
There seems to be a lot of that sort of thing going on here.

Ray


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## JRR (Nov 21, 2020)

I am astonished at the response I have had to my Holt 75  post. I didn’t realise I would tread on anyone’s toes.I just built it and posted as I have done before.
John


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## gbritnell (Nov 21, 2020)

Hi John,
Everyone has their own personal feelings about things. I have been on model engineering forums for many years and some posters welcome contributions to their threads while others don't. Mark feels very personal about his thread so to rectify the issue I would just take down your posting and start your own thread. I have been following this thread from the onset and would like to see it continue but also would like to see your"s too. 
This is a great group which very seldom has any issues, that's why I contribute. Let's keep it civil gentlemen. I'm sure the issue can be resolved amicably.
gbritnell


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## kuhncw (Nov 21, 2020)

I agree with George.  This should be easy to resolve.  I enjoy both threads and hope they continue.

Chuck


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## JRR (Nov 21, 2020)

Hello George'
I have no   idea how to take my posting down. As you can see computing is not a natural with me I really did not realise I had intruded on Mark's site. I thought it was  just a general posting. When this is sorted I will begin a new thread.
John


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## JRR (Nov 21, 2020)

Hi Mark
I must apologise for hijacking your thread.As soon as I find out how to remove it I will do so.
Please do not think I did deliberately.Now I know I should have start my own thread.
John


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## teeleevs (Nov 22, 2020)

I have been guilty of Hyjacking a thread, for that I am sorry.  I am unaware of how to start my own thread for my own Twin Opposed half Scale Onan Engine


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## dnalot (Nov 22, 2020)

JRR said:


> I must apologise for hijacking your thread



Accepted. I gave your post a like when you posted your photos, I said my piece and then I moved on. Time now for everyone to do the same. No hard feelings.

Mark T


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## Cogsy (Nov 23, 2020)

I have started a new thread for Johns' Holt and cleaned this one up a bit. Please continue your story Mark - I've been following along and really looking forward to the completion.


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## dnalot (Nov 23, 2020)

With this post my build of the Holt 75 is all but completed. The reason I say “all but” two of the spark plug wire with boot I ordered are on back order. Anyway I have made all of the parts for the distributor from the last page of the drawings by George Brinell.

The mount for the distributor can be rotated to adjust the timing while the engine is running. I rather like that. I am using a CDI ignition system with a hall sensor. The magnet for the hall sensor is located at the bottom of the distributor mount. A steel disk with 4 holes is attached to the shaft that drives the distributor. As the disk turns it exposes the magnet to the hall sensor through the hole in the disk triggering a spark. The base for the distributor cap is screwed onto the distributor base. It will rotate with the base when timing is adjusted. The rotor is secured to the shaft that drives the distributor. After adjusting the hall sensor to fire number one cylinder at 15 degrees BTDC the rotor was positioned on the shaft pointing at the number one cylinders terminal on the distributor cap.

While I wait for the spark plug wire I will probably start building a base for the engine and a box to carry it in. When the the parts arrive it will be time to see if it will start. Then take some pictures and make a video.

Mark T


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## gbritnell (Nov 23, 2020)

Hi Mark,
I'm glad everything is back on track. As usual the parts look great. I didn't get any responses to the rain cap I posted but I'm assuming you saw it. 
gbritnell


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## Richard Hed (Nov 23, 2020)

dnalot said:


> With this post my build of the Holt 75 is all but completed. The reason I say “all but” two of the spark plug wire with boot I ordered are on back order. Anyway I have made all of the parts for the distributor from the last page of the drawings by George Brinell.
> 
> The mount for the distributor can be rotated to adjust the timing while the engine is running. I rather like that. I am using a CDI ignition system with a hall sensor. The magnet for the hall sensor is located at the bottom of the distributor mount. A steel disk with 4 holes is attached to the shaft that drives the distributor. As the disk turns it exposes the magnet to the hall sensor through the hole in the disk triggering a spark. The base for the distributor cap is screwed onto the distributor base. It will rotate with the base when timing is adjusted. The rotor is secured to the shaft that drives the distributor. After adjusting the hall sensor to fire number one cylinder at 15 degrees BTDC the rotor was positioned on the shaft pointing at the number one cylinders terminal on the distributor cap.
> 
> ...


Will you have this running in December?  I might like to see it in person.


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## dnalot (Nov 23, 2020)

gbritnell said:


> I didn't get any responses to the rain cap I posted but I'm assuming you saw it.



I will be adding that before I post my finale photos.

Mark


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## dnalot (Nov 23, 2020)

Richard Hed said:


> Will you have this running in December?



Probably. It's a hobby not a job. That is what I like about retirement, whatever happens is just fine. And you are always welcome Richard, really enjoyed your last visit.


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## Robert Ritchie (Nov 25, 2020)

Nice work Mark,  two spark plug wires and a box to carry left to go!  Been along road to a very very nice piece of work!


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## rsholl (Nov 28, 2020)

Looking good Mark, shoot me an email at [email protected] with your shipping address. I found a pair of boot/wire assemblies to send you.
Roy Sholl


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## dnalot (Nov 28, 2020)

rsholl said:


> Looking good Mark, shoot me an email at [email protected] with your shipping address. I found a pair of boot/wire assemblies to send you.
> Roy Sholl



Thanks Roy. Check your email. 

So while I await the plug wire I will be making the parts for the rain stop for the exhaust manifold. 

This thread has had over 40,000 views, most of them are probably me but it looks like someone is watching. Thanks to everyone watching and a big thankyou to those that left a comment or two. 

Mark T


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## CFLBob (Nov 28, 2020)

We're watching...


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## Ghosty (Nov 28, 2020)

We are to


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## kvom (Nov 29, 2020)

and Big Brother


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## dnalot (Dec 6, 2020)

So where am I at on this project. With the Thanksgiving Holiday behind me I went back to work on the Holt. Still no spark plug wires with Boot so I robed some wire off another engine and using alligator clips to hold on to Plug. Put some fuel in the tank, switched on the power and turned it over. She fired right up and then quit. Did this a number of times with lots of smoke to show for it. And a water leak on a manifold and oil leaking from the front shaft seal. Also had problems keeping the big flywheel tight to the shaft. To fix that I upped the set screw a size and added a second one.  After fixing the water leak I tried to start the engine again with the same result. I rechecked my settings over and over, tried a different CDI system and still no glory. After taking to many days farting around I finally started looking at the hall switch. What I found is it worked at low RPM but not at high RPM. I have an assortment of hall switches of different makers. Some are smaller than others and it was one of those I had used. So I changed out the hall switch with the bigger one and tried again. She fires right up now and runs but the oil leak is making a big mess. I must have forgotten to install the o-ring to leak this much. I ran a tank of fuel through the motor and the smoke has nearly stopped. Compression has tripled so I think the rings have seated well and the valves are doing their job. Before I work on tuning the motor I need to strip the engine down on the front end to address the oil leak.

Mark T


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## kuhncw (Dec 6, 2020)

Congratulations, Mark.  

Chuck


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## teeleevs (Dec 7, 2020)

Yes congratulations are in order


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## gbritnell (Dec 7, 2020)

Hi Mark,
I'm glad to hear that you have it running satisfactorily. My engine doesn't have oil seals as I built it from the original drawings. When I redesigned it I added the O rings because I would get a little weeping from the crankshaft so thought it would be better with a seal. I'm guessing that it's the O ring. Also my engine has a points setup which was more complicated to make so that's why I designed the Hall setup. I use a variety of Hall sensors on my different engines and don't really seem to have issues with any of them.


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## dnalot (Dec 7, 2020)

gbritnell said:


> I'm guessing that it's the O ring.



I have no oil escaping from the rear shaft seal so I probably forgot to install the o-ring in the front. Its not a lot of oil but it runs along the shaft to the front flywheel and gets flung out making a mess of my work bench. I'm on my way out to the shop now to see what I can do about it. I will take some completed photos once its cleaned up and reassembled. And will post a vid when it is tuned up. This has been a great project and I hate seeing it end. 

While I am bringing this build to a close I am making plans to start building "Bernay's steam engine" from the plans provided by "Jorgensen Steam" that I found posted on this forum. Its an unusual design with lots of interesting moving parts. The photo below is from Free CAD Designs, Files & 3D Models | The GrabCAD Community Library . This is a nice sight offering cad drawings and there are other photos of this engine posted. 

Mark T


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## Richard Hed (Dec 8, 2020)

dnalot said:


> I have no oil escaping from the rear shaft seal so I probably forgot to install the o-ring in the front. Its not a lot of oil but it runs along the shaft to the front flywheel and gets flung out making a mess of my work bench. I'm on my way out to the shop now to see what I can do about it. I will take some completed photos once its cleaned up and reassembled. And will post a vid when it is tuned up. This has been a great project and I hate seeing it end.
> 
> While I am bringing this build to a close I am making plans to start building "Bernay's steam engine" from the plans provided by "Jorgensen Steam" that I found posted on this forum. Its an unusual design with lots of interesting moving parts. The photo below is from Free CAD Designs, Files & 3D Models | The GrabCAD Community Library . This is a nice sight offering cad drawings and there are other photos of this engine posted.
> 
> ...


Did you find drawings for the Bernay's steam engine ?


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## dnalot (Dec 8, 2020)

Richard Hed said:


> Did you find drawings for the Bernay's steam engine ?



Yes I did Richard. I sent you a copy awhile back. I will give you a printed copy on your next visit. 

Mark


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## Richard Hed (Dec 8, 2020)

dnalot said:


> Yes I did Richard. I sent you a copy awhile back. I will give you a printed copy on your next visit.
> 
> Mark


Oh, I thot I must have had the dwgs, but my laptop died, now it's going to be trouble getting some of my latest work off it.  I have most of the stuff bakt up on external discs but nots all.  My wife was kind enough to buy a new laptop for me, it's a nice one too with 17" screen and NOT an hp!  That's a plus.


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## dnalot (Dec 8, 2020)

Richard Hed said:


> my laptop died



I don't know why this often works but it has several times for me. Put your laptop in the freezer for a couple of hours. Then try booting. If it works work fast to recover your files.

Mark T


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## Richard Hed (Dec 8, 2020)

dnalot said:


> I don't know why this often works but it has several times for me. Put your laptop in the freezer for a couple of hours. Then try booting. If it works work fast to recover your files.
> 
> Mark T


it's reporting that the fans are not working which is true--they are rattling around.  how did you find out about that?


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## dnalot (Dec 8, 2020)

Richard Hed said:


> it's reporting that the fans are not working which is true--they are rattling around. how did you find out about that?



Computers don't like heat so I tried freezing balky laptops to see if that helped. It often did but just till they got hot again. 

Mark T


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## Robert Ritchie (Dec 8, 2020)

Full speed ahead Mark, next project looks good!


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## Richard Hed (Dec 8, 2020)

dnalot said:


> Computers don't like heat so I tried freezing balky laptops to see if that helped. It often did but just till they got hot again.
> 
> Mark T


that might be possible to get some of my important stuff off before it crashes agai.  On the other hand I can get it lookt at for 50$ and maybr repaired long enough to get the good stuff off.


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## elliot9797 (Dec 9, 2020)

I believe a casting kit for this Bernay’s engine just popped up on eBay.


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## dnalot (Dec 9, 2020)




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## dnalot (Dec 9, 2020)




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## dnalot (Dec 9, 2020)




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## dnalot (Dec 9, 2020)

After I get the Holt tuned up I will post a video

Mark T


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## kuhncw (Dec 9, 2020)

Very well done, Mark.   Thanks for a great thread.

Chuck


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## Robert Ritchie (Dec 9, 2020)

Success looks so perfect,  all of your hard work shows.  Now take a deep breath time to build Bernays Steam Engine!  The photos are great, the detail of the build really looks sharp.  Well time to clean the shop and get ready for your next build!


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## CFLBob (Dec 9, 2020)

Gorgeous work, Mark.  Can't wait to see and hear it running.


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## Rockingdodge (Dec 10, 2020)

Richard Hed said:


> that might be possible to get some of my important stuff off before it crashes agai.  On the other hand I can get it lookt at for 50$ and maybr repaired long enough to get the good stuff off.


Just take the drive out and put it in the spare slot in your new laptop and you'll be able to access all your files.

Roger


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## gbritnell (Dec 10, 2020)

Really outstanding work on your engine Mark. All the different colors really make it stand out. How is the overflow tube plumbed into the radiator?
gbritnell


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## dnalot (Dec 10, 2020)

gbritnell said:


> How is the overflow tube plumbed into the radiator



The top end is epoxy glued into the hole in the radiator tank. Was a tight fit that required a tap with a soft mallet.




gbritnell said:


> All the different colors really make it stand out



Thanks for your comments George. I like to go for "a look" when building a model. I loved your all (well mostly)
aluminum look on the holt you built. And thanks again for the great set of drawings. I see you get up early, you must have a cat. 

Mark


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## Richard Hed (Dec 10, 2020)

Rockingdodge said:


> Just take the drive out and put it in the spare slot in your new laptop and you'll be able to access all your files.
> 
> Roger


I was thimking of doing something like that if necessary but not to open up th e new one, maybe attach a cable.


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## reichpaul630 (Dec 10, 2020)

i found that the condition & cleanliness of a computer fan determines the reliability/lifetime, esp. with laptops.
disassembled and thoroughly cleaned the fan of a flaky HP laptop a year ago (with jeweler tools!). never had another
problem.  ran faster too!

FWIW, the increasing use of "solid state" drives tends to remove a major impediment to reliability.


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## Richard Hed (Dec 10, 2020)

reichpaul630 said:


> i found that the condition & cleanliness of a computer fan determines the reliability/lifetime, esp. with laptops.
> disassembled and thoroughly cleaned the fan of a flaky HP laptop a year ago (with jeweler tools!). never had another
> problem.  ran faster too!
> 
> FWIW, the increasing use of "solid state" drives tends to remove a major impediment to reliability.


The new one is solitd state, only prob is that it is too small of a drive


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## dnalot (Dec 10, 2020)

Proof of life. Still needs to be broken in and I will need a camera man on my next shoot. I love it when the flywheel dosen't wobble.




 

Thanks for watching

Mark T


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## Rockingdodge (Dec 10, 2020)

Richard Hed said:


> I was thimking of doing something like that if necessary but not to open up th e new one, maybe attach a cable.


Won't be a problem opening up the new one, they normally have a small cover similar size to the drive just so that you can add a second drive, doesn't void the warranty.


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## Richard Hed (Dec 10, 2020)

Rockingdodge said:


> Won't be a problem opening up the new one, they normally have a small cover similar size to the drive just so that you can add a second drive, doesn't void the warranty.


Really?!  That's goo news.


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## CFLBob (Dec 10, 2020)

dnalot said:


> Proof of life. Still needs to be broken in and I will need a camera man on my next shoot. I love it when the flywheel dosen't wobble.
> 
> 
> 
> ...




Tells me the video is private and I can't watch.  Am I the only one?


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## dnalot (Dec 10, 2020)

Deleted to prevent confusion


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## Richard Hed (Dec 10, 2020)

dnalot said:


> I can see it but then I posted it to youtube. I clicked on the link in your post and it works as well.
> 
> I went back and checked the box saying it was safe for kids. Does it work now?
> 
> Mark T


doesn't work


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## Ghosty (Dec 10, 2020)

Mark, it still come up as private, when you loaded it up to YouTube it must have been loaded up as private, not public.
Cheers
Andrew


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## dnalot (Dec 10, 2020)

Ghosty said:


> Mark, it still come up as private, when you loaded it up to YouTube it must have been loaded up as private, not public.
> Cheers
> Andrew



I looks like I saved the upload as a draft. Have now published it. Does it now work. Life was once so simple.

Mark T


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## Ghosty (Dec 10, 2020)

Yep, video works, it runs well for a new engine, great work.
Cheers
Andrew


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## johwen (Dec 11, 2020)

Excellent work and something to be proud of Richard. Johwen


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## gbritnell (Dec 11, 2020)

Hi Mark,
My engine has probably at least 100 hours of running time on it. The compression is great. When I got the engine tuned to its best running settings it would puff a little smoke upon acceleration. I tried several different venturi sizes but had the same results. Mine will idle all day long with no smoke but when I rev it up it will puff for a few seconds then clean out. My best guess is that with the updraft style manifold it is puddling gas in the horizontal part of the runner and when revved up it pulls that wet fuel and creates the smoke. While running it uses very little oil so that's all I can figure it is. The engine isn't very sensitive to timing except when running slow. While idling I can retard the timing and it will bring the idle down even further but then it won't rev cleanly. 
Your engine looks and sounds great. Tinker with the timing and carb settings for best results.
gbritnell


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## CFLBob (Dec 11, 2020)

The video works for me now.  Looks great!


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## reichpaul630 (Dec 11, 2020)

truly a work of art.  thanks for posting the vid!

paulr


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## Robert Ritchie (Dec 12, 2020)

All those hours work  really paid off,  your project is very very nice and complete.  I enjoyed listening to to your motor in action.  I cant imagine how you must feel, the skills it took to complete your motor are rare.   I await your next project from start to finish your talent continues. 

                                                            Congradulations!
                                                                   Mark


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## dnalot (Dec 13, 2020)

Thanks for the comments guys. I have been sitting at my desk with my feet up taking it easy before starting another project, whiling away the time playing Kerbal Space. If you aren't a Kerbalnaut your really missing out. I have ordered a chunk of cast iron for the block of the Bernay engine so I am now committed to my next project. 

Happy Holidays 

Mark T


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## Robert Ritchie (Dec 14, 2020)

Beam me up Scotty!  Cant wait tell your next build start!


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## Robert Ritchie (Mar 9, 2021)

Wow, you've been busy, nice work Mark.  Get your chores done and get it done I can't wait to see the finished project!


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## fourstroke (Aug 27, 2022)

dnalot said:


> Hi
> 
> Well I had a great summer despite being in lock-down. Got out of the shop and out into the sun for a few weeks.  Its Fall now and its wet out so I got myself back into the shop to work on the Holt project. This update shows the governor and the linkages connecting it to the carburetor.
> 
> ...


Hi
I've been reading your thread as I'm in the process of building one of these engines
My question is, is there a spring that fits inside the governor housing to work against the  action of the flyballs? 
Thanks 
Dougie


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## kvom (Aug 27, 2022)

Great job.


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## dnalot (Aug 27, 2022)

fourstroke said:


> I've been reading your thread as I'm in the process of building one of these engines
> My question is, is there a spring that fits inside the governor housing to work against the action of the flyballs?


I don't remember there being a spring. I will look when i get home and if there is I will let you know.

Mark T


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## dnalot (Aug 28, 2022)

dnalot said:


> I will look when i get home and if there is I will let you know.


There is no spring.

Mark T


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## fourstroke (Aug 28, 2022)

Thanks for the reply 
Dougie


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## gbritnell (Aug 28, 2022)

There should be a spring inside the governor body (.250 diameter hole) The part with the pivot posts slides in and out of the body. The spring returns the post.
The spring should fit in the .250 bore and be .018-.020 diameter wire. and about .19 long. The tips of the flyball arms (.126 dimension) will need to be adjusted to allow the flyballs to move out freely. 
I'm sorry for the inconvenience. I am changing the drawing and will get it out to you. 
gbritnell


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## fourstroke (Aug 28, 2022)

Thanks George 
I wondered what pushed the balls back
I've got a fair way with the castings I made, would you be interested in some pics
Thanks 
Dougie


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## gbritnell (Aug 28, 2022)

Hi Dougie,
I've sent you an updated drawing. Thanks for bringing it to may attention. Yes I would love to see pictures of the castings.
gbritnell


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## fourstroke (Aug 28, 2022)

Thanks George 
If you can view tiktok, my user name is weedougie1l
I have documented the build from castings to present in video 
I have to confess when I had your drawings printed I had them done on A3 paper, just so I could see them better, but that size is 1.5x A4 which is closer to your original 
Consequently, when I took the sizes from the drawings I was 1.5x too big. I didn't realise my mistake before I had made the crankcase patterns, by then it was too late so I just carried on
If you see my videos, let me know what you think 
Regards 
Dougie


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## reichpaul630 (Aug 28, 2022)

fourstroke said:


> Thanks George
> If you can view tiktok, my user name is weedougie1l
> I have documented the build from castings to present in video
> I have to confess when I had your drawings printed I had them done on A3 paper, just so I could see them better, but that size is 1.5x A4 which is closer to your original
> ...


Just took a look qt your work on Tik Tok. never would have thought to use tik tok that way. quite an impessive collection   -thanks!


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## fourstroke (Aug 28, 2022)

reichpaul630 said:


> Just took a look qt your work on Tik Tok. never would have thought to use tik tok that way. quite an impessive collection   -thanks!


Thanks


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