# First IC engine design and build



## retailer (May 7, 2019)

Late last year as my Quorn T&C grinder was nearing completion I was planning on starting an O gauge live steam loco  but I came across the Demon V8 build log by Steve Huck I must say it impressed me and and I decided then to put off the loco project and swap it for a running V8 - as I had a few months to go on the Quorn I decided to have a go at my own design. 
Not having any experience with model engine design there is always a chance that the design will be difficult to build or even worse may not be a good runner. In that event I would simply purchase a set of Little Demon plans, by all accounts Steve had done a great job of the plans and build details, the design is proven with quite a few examples built and running and being a forum member he is always ready to help out with advice. 

The Quorn is now finished to the point where it is use able and my plans have reached the point where I could start actual machining. Bore and stroke is .625" - if this sounds like the PeeWee V4and the Steve Huck V8 that is because I copied these sizes from those two engines, mainly because I know rings can be made that size, I have not made rings before and being my first IC engine there is a lot of info in the forum posts on ring making to help me - the rest of the engine is my own design.

I started with the block, a square extrusion about 6inches long, final length will be a bit over 5.25 inches, extrusions may look square but are not good enough to use with out being squared up.

For this I used the lathe checking each time that the newly machined surface was parallel to the lathe bed, once squared up I mounted the block onto a steel back plate that was drilled to be bolted to my rotary table. The idea is that once the block is setup parallel to the mill table I can machine each surface by indexing the rotary table.

Before I set it up in the rotary table I spotted the holes for the crank and cam as I will probably machine away the face I am using as my datum point. Once bolted to the rotary table I set it square and parallel to the mill table with the rotary set on 0 deg. an angle plate clamped to the extrusion was needed to steady it as I could see it wobbling around once I started boring the holes for the cylinder liners. I don't have any sort of CNC setup but I do have the luxury of a DRO on my mill which does take some of the pain out of it.


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## stevehuckss396 (May 7, 2019)

I'm in!  Lets do this! and yes we will be here if there is any questions.


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## retailer (May 9, 2019)

Thanks for the encouragement it is much appreciated. I've made a bit more progress and will get a post up shortly.


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## retailer (May 11, 2019)

I have progressed a bit further with my engine build, all of the bores for the liners have been drilled bored and countersunk, I plan to have liners a push fit and seal off the water jacket with O rings.
I only have a set of expanding bore gauges for internal measurements and I find they can be a bit hit and miss - in the lathe is usually ok as I can move the saddle back out of the way and get the gauge nice and square, in the mill though the boring tool was partially in the way making in a bit harder to get the gauge square, I ended up turning up a go gauge - making small adjustments to the boring tool until my gauge was a nice push fit.

The cylinder head bolt holes were drilled and tapped metric 3x0.5 and then the cutouts for the push rods were machined - all operations for each cylinder bank were completed before I rotated the block to do the other bank. While drilling the head bolt holes on the left bank I noticed that the holes looked to be displaced towards the front and on checking the front face of the block against my DRO I found it was set at .02" rather than 0" this threw out of the head bolt holes on the left side by .02", not a disaster as it is not a huge amount and I can compensate when I drill the head bolt holes but it is  still not great . Theoretically once I shut down for the day as long as I don't move the mill table the settings should be the same next time it is turned on so that sort of thing should not happen, I'll be checking and resetting the x/y zero points each time I start up the mill from now on.

I always thought that machining cast iron was messy but I'm starting to think AL is worse, a lot of the swarfe is thin flakes and when it is brushed away it ends up all over anything that's close by. At the end of the day the piece of AL was starting to look a bit like an engine block


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## retailer (May 15, 2019)

Bores, tappet holes and valley cut out all finished the block was rotated 180 deg to cut out the crank web clearances, I did make a couple errors though - the final dimensions were not affected but it looks sloppy and is sloppy, not happy about it. While it won't be seen once the sump is on but I'll still know it's there. The final operation while it is on the rotary table will be to drill the sump bolt holes and also the main bearing cap bolt holes.


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## retailer (May 21, 2019)

Family stuff has kept me busy but I have managed to machine and fit the main bearing caps (with temporary screws), I just need to figure out how to bore the cam tunnel and probably more importantly the main bearings, one of the mains will also double as the crank thrust bearing. None of the small boring bars I have will reach to the back of the block so I may experiment and see if I can bore the front and rear holes for the ball races turn up a pair of brass bushes and then use these as supports for a line boring bar to do the 3 central mains or perhaps I'm over thinking it and a plain simple long boring bar will do the job.


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## retailer (May 22, 2019)

I decided to mount the block in the mill and bore the rear main first, turn the block over and bore the front main and then turn up two brass bushes for the front and rear mains and use these as guides for a "line boring" set up to do the three middle main bearings - if I could pull it off then all of the mains should be in perfect alignment.  

I  started out on the rear main first drilling a 0.25" hole, then gradually opening it up to 0.5" with end mills and then continue to the target size with a boring head - my target id size was .708" (18mm) and as I progressed I could see the main bearing cap getting thinner and thinner in the area next to the screw head cut out, by the time I reached an id of .630" (16mm) and realised that if I continued through to my target dimension of .708" the main bearing cap would not have much meat left on it at all, I went back to my cad drawing and found that the thickness would only be .058" or less than 1.5mm - this may or may not be sufficient thickness - but as it doesn't look right  and not wanting  to risk bearing failure after the engine is running I decided that I would rather make up new front and rear main bearing caps and complete the front and rear main boring with the caps 'in situ'. Adding thickness just means the screw cutouts will not go down so deep. Bit of a nuisance as need the mill to make the bearing caps.


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## minh-thanh (May 22, 2019)

Hi  retailer !
Do you use water radiators?
If so, can you tell how you sealed it above and below the cylinder?
Thanks !


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## retailer (May 23, 2019)

With regard to the water cooling I plan to have 2 O rings one near the top and one near the bottom, I hope I can work out a way to return the coolant back through the heads and to the top of a radiator.

With the block remounted in the mill and my new main bearing cap in place I started to bore it to size and saw that the boring I had done the day before appeared to be the incorrect distance from the cam tunnel, I took some quick measurements as best I could and sure enough it seemed to be out of place - must have made an error when I zeroed in my two datum faces so I zeroed in my two datum faces again and repositioned the block over the boring head with the same result. I decided that the hole I had bored yesterday was out of place  around .02" and would continue on - it seemed good fortune was smiling on me as if I had completed the job the day before it would have resulted either in a slightly misplaced crankshaft or even worse the front and rear bearing would not line up.

Got the rear main bored and fitted one of the bearings - perfect fit.


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## minh-thanh (May 25, 2019)

"With regard to the water cooling I plan to have 2 O rings one near the top and one near the bottom, I hope I can work out a way to return the coolant back through the heads and to the top of a radiator."

Thanks retailer !


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## retailer (May 25, 2019)

The front and rear main bearings holes were bored but not without some drama - to position the holes the left and right cylinder bank were set to be in the X and Y planes  - the top of each bank was then used as the zero datum point, moving the mill table 1.847" in both the X and Y plane had the boring head positioned over the main bearings. I did the rear main first and then flipped the block over to do the front main and  proceeded to move the mill table from the zero point a distance of 1.874"  in  both the X and Y directions I finished boring the hole with the main bearing cap in place and congratulated myself for getting the hole the right size - the bearing was a tight push fit in the hole but - on removing the bearing cap I found that the bearing cap would not fit over the bearing - how could that be I had only a minute before pushed the bearing into the finished hole - then it dawned me the hole was not on the centre line of the main bearing cap and block I checked the DRO and saw that I had 1.874" on both the X and Y readouts I silently berated myself over this stupid error. I slunk back inside to check my cad drawings to see if there was a reasonable fix. I was in luck I had bored the hole away from the block not towards it, I just needed to make another main bearing cap and rebore the hole the same diameter but in the correct position, it was done with out drama.

 I found the end of a broken end mill and silver soldered it into a short length of 0.5" rod  to make a long reach end mill with this I was able to bore out the next two main bearings down, I flipped the block over again and bored out the last remaining main bearing, they are all very very close to final size and once I turn up a test rod and bronze bushes tomorrow I'll be able to see if they are all in alignment, if they are I'll leave them and alter the main bearing bushes to suit if not then I'll need to rig up a line boring tool to bring them into line.


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## retailer (May 26, 2019)

Sadly the main bearings did not all align - out by around .003" - .004" not much but still too much, so I had to get to work and make a line boring setup, a bush at each end and a sliding boring bar that carries an adjustable cutter, the boring bar passes right through both front and rear bushes.

The cutter is held with a grub screw in the end and a small diam rod that passes through the boring bar to clamp the cutter. The cutter is a piece of 0.125" diam HSS,  being that small it took some patience to grind something close to the correct clearance angles on the cutting edge, I eventually gave up with the bench grinder and dremel and put my new T&C grinder to use, while I didn't bother to get precise angles and only eyeballed them the setup allowed me to hold the small cutter at a constant angle.

Once assembled in the block and mounted in the mill I nudged the cutter up a few thou at a time until all traces of the old bored hole had gone I then gave it a few more thou just to be sure, the size of hole for the main bearing bushes went up from .503" to .513" - once done I turned up another bush at .513" and was able to slide it along the test bar with no binding, so should be all good to get on with the crank.


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## minh-thanh (May 26, 2019)

retailer !!
The way and the tool  that I need for my project 
Thank you very much !!


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## retailer (Jun 2, 2019)

To prepare for boring out the cam tunnel I drilled 1/4" from both ends, as I expected the holes did not quite meet in the middle, looking through from one end to the other I can see it is not much as  1/4" rod will pass right through  if the holes do not quite meet in the middle it really doesn't matter as long as the cam will pass through. I will however try to get the cam tunnel true by finishing off the hole with and end mill from one end to the other before I finish off the bearing recesses at each end with a boring bar. I made up a long end mill using the end of another broken end mill silver soldering it into a length of 12mm bar and reground the dull cutting edges on my T&C grinder, hopefully it will run true and nor wander it only has to clean out out around .03" of diameter.

While I was making up the  long end mill I came to the conclusion that I may not have left enough room at the rear of the cam tunnel for the bevel gears that drive the distributor. Checking my CAD drawing I found I had less than 0.45" - could I get bevel gears that small ? I decided to cut my own, I haven't cut gears before but thought it can't be that hard so I ordered a set 0.4mod cutters, I believe this translates to around 64DP.

While waiting for the  cutters to arrive I poured over Mr. Law's book on gear cutting, it didn't seem to make much sense at first but I eventually realised that I needed to work from the small end of the bevel gear back towards the large end. I found a web site by a company called KHK that has an online spur gear designer and played around with a few sizes until I came up with one that looked like it would fit using the spur gear info as a starting point -I came up with 16 teeth 0.28" at the small end and 0.41" at the large end.  After 6 initial failures I eventually had success, the failures were due to my incorrect calculations on the amount to roll the gear back, with a 32 hole index plate on a 72:1 rotary table I calculated a roll back of 5.625deg which is correct, 5 deg is one turn I got that right but came unstuck with the 0.625deg, I assumed it was 0.625 of 32 so I rolled the gear back 1 turn plus another 20 holes which turned out to be an extra 3 deg rather than the required 0.625deg. 

I now have the bevel gears for the distributor drive I doubt they are perfect due to my method of calculating the size of the blank, but they do look ok under a magnifying glass and mesh together nicely I set them up to mesh and can't feel any binding and there seems to be minimal backlash, spinning them over with a cordless drill did not show up any problems. The pic shows them next to a 3mm screw.


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## retailer (Jun 15, 2019)

I've been getting to work on the crankshaft and working through how it will be machined - it seems that the crank appears to be one of the most difficult things to do. I started with a 1inch diam length of some sort of carbon steel or possibly tool steel which came from gumtree, the seller thinks it is 4140 or similar, we cut off a small piece and heated to bright red and quenched in water and it did come up hard, a file just slide over the surface. The bar looks like hot rolled MS but has a green stripe painted along it's length so I doubt it is just plain hot rolled MS,  it machines nicely with an acceptable finish.

I went back to my cad drawing and dimensioned a few drawings to give me distances from my datum point to the main bearings and big end journals. One end was centre drilled to mark the axis of the main bearings and the other end was also drilled for main bearing axis and also the big end journals, in the lathe the main web diam was roughed out slightly over size and front main bearing machined to give me a datum point, once setup in the rotary table I worked from my drawing and roughed out slightly oversize the centre 3 main bearing, and then the bigends indexing it with the rotary table. I was able to get the main bearings round but still left them slightly oversize and will do the last of the machining in the lathe. The big end journals were left square, it took a while as I kept the depth of cut small .015" near the rotary table and at the other end only  about .005" to achieve a full depth of .630". I used a freshly sharpened 3/16" and new 5/16 end mill.

I finished and had a look and at first I didn't see it then it dawned on me I had screwed it up, in case you can't see it the 2nd and 3rd big end journals should be diametrically opposed, chalk it up to experience - I'd like to think I won't make that mistake again, I'd like to lay the blame on something that distracted me but I know it was just my inattention to what I was doing. On the plus side I won't have to wait to start again as I purchased a 1 meter length of bar, it's a shame to waste the material, perhaps it will make a good paper weight.


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## stevehuckss396 (Jun 15, 2019)

I agree with you. The crankshaft can be one of the more difficult things to make. Once you get past that, it's all down hill.


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## bluejets (Jun 15, 2019)

If the material is 4140 then it will not require any heat treatment.
A plus as it would more than likely bend the crap out of it.

A real shame about the boo-boo. 
I once made an error making a multi cylinder cam. 
Had the engine rotation one way, cam the other. 
Easy to make the mistake BUT in any future machining operations I always scan for any possible error areas and make LARGE  notes on the drawings.

Hope you wedge those cut-out areas when you move to machine adjacent journals.
Could end up with a multiple stroke engine if you don't.


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## retailer (Jun 16, 2019)

Even though the general concensus seems to be that the crankshaft is the hardest part to make it is the distributor that has me most concerned, I feel the crankshaft is quite do-able as long as it is taken slow and steady and without my stupid lapse in concentration it may have been done by now.

I'm still not sure how to tackle the distributor cap - I don't have any form of CNC, but I think it can be done in the mill with the use of the rotary table, it will require multiple setups - one for each diameter so there would be 10 separate setups and if I radius the lugs on the side that are used to hold it down to the distributor body that will be an extra 2.

I've considered making a full distributorless ignition setup using coil paks and an Ardunio or Picaxe type chip and for me it would certainly be easier - but it just would not look right so I'll give the distributor my best shot.


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## bluejets (Jun 16, 2019)

retailer said:


> I don't have any form of CNC



Many of us don't but we make do and usually do ok.

If you think a distributor is an unreachable goal, take a look at this engine.
ALL from solid.


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## Cogsy (Jun 17, 2019)

Here's a few pics of a cap that I roughed out without any sort of plan using a rotary table and a quick home-made lug rounding tool. It turned out ok (although the plastic I used wasn't the best for machinability). It wasn't a difficult job and I'm sure I could have done much better if I'd spent a bit more time (soon I have to re-visit this one so I'll see how it goes).


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## retailer (Jun 17, 2019)

bluejets - I've seen that model online somewhere but can't recall where, I do recall though thinking that it is a superb model of a blower Bently, the model is up there with the best of the best.


Thanks Cogsy that little cutter is quite ingenious and looks to be very similar to an annular cutter or rota broach, I hadn't thought of that. Looks like my failed crankshaft can be put to good use by making a similar cutter out of it when the time comes.


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## stevehuckss396 (Jun 17, 2019)

If the cap is the big hang up Roy sholl from s/s used to sell caps all the way up to 9 cylinders. Can see if he has one then make a distributor to fit.


Cncengines.com


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## bluejets (Jun 17, 2019)

In the past, I have basically gone for a radius contact/pickup arrangement with a clear lid with the centre ht input for simplicity.

Plan to make up the next one for the V8 using glass epoxy and plug and mold. 
Have noted in the past that epoxy tends to be rather heat sensitive so perhaps polyester resin instead.

My mate George is building a very similar design but with a twin overhead cam arrangement.
Plan there is for dual dizzy. 
Will post eventual outcome. Busy rebuilding the crank grinder feed arrangement.


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## retailer (Jun 17, 2019)

bluejets: I have seen those distributors with the radial leads, and they may be easier to make I'll have to see when I get to that point.

stevehuckss396: Thanks for the info on the availability of distributor caps I'll keep it in mind if I fail to make something that is decent and workable - I think it will be a while before I get to that stage, soon I'll need to temporarily put the V8 project aside for a few months, I promised my son I'd make him a Fender Deluxe reverb copy, I wound the transformers late last year and he keeps asking if I've made any progress.


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## retailer (Jun 21, 2019)

My next attempt at a crank went a bit better, roughed it out again in the mill this time with the big end journals in the correct place. I recall seeing a youtube machining tutorial video where a small model engine crank is machined by using an offset hole in a soft collet, I though it looked like a good idea but finding a large enough collet was a problem, I then thought that maybe I could simulate a collet and came up with a crank machining jig that provided support for the crank while allowing all of the machining to be done right up next to the chuck - ideally a square section of MS would have been easy to use but as I couldn't source a suitable 4" length of  2"squ  so I machined a couple of flats on a 2.150" diam chunk  of 1020, the flats make it easier to be gripped off centre in a 4 jaw chuck. Two holes were drilled and tapped 1/4x20  for grub screws to hold the crank in the jig.

The jig was set up in the mill with one of the flats parallel to the Y axis two marks were centre drilled at one end - one on centre and the other in the Y direction a distance half of the crank stroke (.312") off centre. In the 4 jaw a shoulder was machined once the centre mark was clocked with a dial gauge - this centre mark would eventually be machined away so the shoulder would then serve the same purpose ie:- reference surface to recentre the jig. The jig was then re-centred this time on the .312" offset and a hole bored through from front to back, the hole must be sized such that the crank fits though with a firm push, the jig is now ready to use. The jig is set up in the 4 jaw using the turned shoulder as a centre reference and the crank is pushed in with the first big end journal just poking out and rotated so the centre mark in the end of the crank for that journal runs true and the grub screws tightened, this can be checked with a bar that has a 60deg taper at one end and a centre in the other, I call it a wobble bar but it probably has an official name, once it is right this puts the bigend journal on the centre line of the lathe and it can now be machined, the unsupported end has no stress put on it but it wouldn't hurt to use a live centre to steady it. The bigend journals can all be done the same way one at a time, with the machining being done up next to the chuck the tendency for the crank to flex would be minimised.

Once the bigends are done the jig can be recentred this time using the internal bored hole as a reference and the main bearings can be machined in a similar way, although I may do the last few thou of the mains between centres I'll see how it pans out.

How well does it work and is it easier than other methods? this I don't know as I haven't machined a crank of any sort before and I have only just set it up ready for the first journal to be done, I may find it is a waste of time - my main concern is keeping things square and parallel, and possibly the two grub screws may not hold the crank enough to withstand an interrupted cut - while the jig uses a close bored hole it is not really a collet and so does not have the same precision.


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## retailer (Jun 23, 2019)

The first big end journal finally finished to size - I found the setup not as easy as I thought. I  imagined that I would be able to insert the crank into the offset bored hole, rotate the crank and use a wobble bar to locate the bigend journal on the centre line of the lathe but it proved to be very touchy - just nudging the crank a round a degree or two was just about impossible, it would overshoot one way and then the other, I did eventually get it to within 1.5 thou (about .04mm) but this was probably more blind luck than skill. I had to resort to adjusting the 4 jaw chuck to bring it on to the lathe centre line and the end result was better than 1 thou or about 1.5 divisions of my .01mm dial gauge.

I read gbritnell's post on another forum about making a crank and duplicated his idea for a lathe tool, I ground mine though from a 1/2" square HSS blank, roughing it out with a side grinder and finishing it off in the T&C grinder to give it side rake and front to back relief, the end of the tool is notched and while I'm not 100% sure of the function of the notch but I included it - I'm guessing it is to reduce the contact area between the tool tip and work to possibly help with chatter. It was slow going low speed small cuts, I did get an occasional hint of chatter and curiously it was at the end of the crank pin journal that is closest to the chuck I would have thought  the setup would be more likely to chatter further away from the chuck. Haven't had much shed time these last days so only the one journal finished so far.


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## retailer (Jun 24, 2019)

I found some time to make a bit more progress with the crank today, the big end journals are around a thou or so oversize so I should be able to polish out the majority of the machining marks same goes for the mains, I did find though that in roughing out the crank on the mill I went a bit deep on one of the big end journals and was unable to cleanup it up fully, if you look closely at the last pic it can be seen as a small flat spot, I don't think it will affect the way the crank works and given the amount of time that hasgone into the crank so far I don't think it is bad enough to scrap the crank.

I swapped out the plier tightened brass threaded rod that I used to secure the crank in my jig for proper grub screws, they hold the crank tighter which eliminated the occasional chatter I was experiencing, the brass threaded rod stuck out a long way and I was always mindful of it and making accidental contact in which case my fingers would have come off second best.

Once all of the big end journals were completed I centred the bored hole in the 4 jaw and worked on the mains bringing them to size plus 5 or 6 thou, (about .15mm) so I could finish off the mains between centres. Once between centres I experienced a fair amount of chatter when I tried to finish them off to size, probably should have put in something to support the crank across the big end journals, but it was getting late and a bit cold in the shed so it was slow and steady with very small cuts, I think I have the worst of it done, I still need to bring the ends to size for the ball races, this will be between centres so I'll have to rig up some support across the big end journals as there is more than just a few thou to remove.


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## minh-thanh (Jun 24, 2019)

Thank you for sharing !


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## bigearl91 (Jun 24, 2019)

retailer said:


> I found some time to make a bit more progress with the crank today, the big end...



Lots of patience, good job. Thanks for sharing.

Earl


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## Luiz Fernando Pinto (Jun 25, 2019)

good job


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## deeferdog (Jun 25, 2019)

Love your patience retailer, something I sadly lack. Would it be a rude question to ask which country you are located? I understand if you don't want to answer this. Cheers, Peter


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## retailer (Jun 26, 2019)

I'm in Oz - Adelaide SA to be specific - yes patience is needed, the small stuff is certainly a different ball game.


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## retailer (Jun 27, 2019)

I made up some expanding spacers to fit in the big end journal space and taking very small cuts turned the mains to final size, next were the front and rear mains turned down for the 8x16x4 ball races, it all looked quite good. I mounted the crank in the block and it spun over quite nicely, however I noticed what looked like run out on the 3 internal mains, must be an optical illusion I thought, they were turned between centres and I did check them with a DTI, they had no run out. Just to be sure while the crank was mounted in the block I placed a DTI over each main and checked it - almost 3 thou run out ! checking with my calipers two of the 3 mains were tapered by around 2thou I was stumped. No option but to put it back in between centres and rectify the run out and taper, this time I double checked  - no run out and no taper.
Once again back into the block and again I'm sure I can see run out in the mains when the crank is spun over, I check with a DTI and yes there it is, the run out varies from from 2-3thou on each of the 3 mains, the front and rear are fine, time to go inside, have a coffee and give it some thought. I come to the conclusion that in applying some pressure/preload on the crank from the running centre the crank is flexing - perhaps only a thou or so and once machined and the preload is removed it flexes back and we have run out, to check on this I remount the crank and with a DTI on one of the mains I gradually put some preload on the crank, sure enough I get a reading of 2 - 3thou, this is with the adjustable spacers in place, not sure what to do I decided to put minimal preload on the crank so I can cleanup the mains and eliminate the run out, while I did have a hint of chatter before which was most evident if I let the cutting tool rest in the one place, with less preload the chatter was constant and unacceptable making it impossible to get a good finish, I increase the preload bit by bit until I find a satisfactory setting where I can machine out the chatter marks.

Job done I once again set it in the block and you guessed it there is run out but only around 1.5thou, I was hoping to get it less than 1/2 thou so there would be no tight spots, then I thought that 1.5 thou is not that much and to get it to 1/2 thou I only need to remove 1 thou from 1 side so with a felt tip marker I marked the high side and with the crank mounted in the vice used some 600 emery on the high side gradually working around with less pressure, bit by bit I managed to get it down to around 1/2 thou, I know it's probably not perfectly round anymore but it is round to within 1/2thou. I do the same to the other 2 mains, the good thing is I have all of them with in the spec I wanted but the bad thing is they are now under size which can be compensated for when I make the three split bearings but worse they are all a different size now which means I'll have to number them. I know my method is not exactly precision machining, maybe if I had used a different material rather than an unknown I may not have had these issues.


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## propclock (Jun 28, 2019)

Absolutely gorgeous.


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## deeferdog (Jun 28, 2019)

I've had issues with single throw crankshafts! I think your work is excellent and the results prove that. Thank you for posting all this, I'm pretty sure most will agree with me that reading about other members travails helps us through our own, particularly with crankshafts. Cheers, Peter


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## retailer (Jul 8, 2019)

Managed some more time on the V8 - cut a couple of pieces of brass from a odd shaped lump and machined up 2, 8mm x 16mm rectangles that were soft soldered together make up one piece with a 16mm x 16mm square cross section. A centre pop mark was put in the middlle of one end right on the join line and the centre pop mark centred in the 4 jaw chuck. It was then a simple turning job to make each of the 3 split bearings, a few seconds with a small blow torch was enough to separate the bearing halves.
I'm not sure what is done in the model making world to locate bearings of this type or even if they have them at all but I recall seeing locating pegs on the bearings of my small window VW beetle when I pulled the engine out to fix a dropped valve, so I decided use pegs to locate the main bearings - the centre bearing is also the thrust bearing, with no clutch assembly it is doubt full if it is needed at all.


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## bluejets (Jul 8, 2019)

retailer said:


> Managed some more time on the V8 - cut a couple of pieces of brass from a odd shaped lump and machined up 2, 8mm x 16mm rectangles that were soft soldered together make up one piece with a 16mm x 16mm square cross section. A centre pop mark was put in the middlle of one end right on the join line and the centre pop mark centred in the 4 jaw chuck. It was then a simple turning job to make each of the 3 split bearings, a few seconds with a small blow torch was enough to separate the bearing halves.
> I'm not sure what is done in the model making world to locate bearings of this type or even if they have them at all but I recall seeing locating pegs on the bearings of my small window VW beetle when I pulled the engine out to fix a dropped valve, so I decided use pegs to locate the main bearings - the centre bearing is also the thrust bearing, with no clutch assembly it is doubt full if it is needed at all.



Brass or bronze...??? Brass will be too soft for bearing material.


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## retailer (Jul 8, 2019)

Brass or bronze that's a good question, I'm not sure and I don't know how to tell them apart, my bearings were cut from a failed attempt to make twin cylinder steam tractor. The engine has ball races at both outer ends so even if the material is brass I don't think that there will be a huge amount of wear  for the amount of run time the engine will get, once I get past the initial excitement and all of my mates have seen it, it will probably just sit in one of our bookcase cabinets as a display piece  sadly we don't have model engineering shows where people can exhibit and run their creations in my area.


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## bluejets (Jul 9, 2019)

retailer said:


> Brass or bronze that's a good question, I'm not sure and I don't know how to tell them apart, my bearings were cut from a failed attempt to make twin cylinder steam tractor. The engine has ball races at both outer ends so even if the material is brass I don't think that there will be a huge amount of wear  for the amount of run time the engine will get, once I get past the initial excitement and all of my mates have seen it, it will probably just sit in one of our bookcase cabinets as a display piece  sadly we don't have model engineering shows where people can exhibit and run their creations in my area.



Looks very much like brass to me.
Brass is shiny yellow whereas most bronze is more orangy colour, the exception being copper bronze which is very difficult to machine and very rarely, if ever, used in modelling.
One can usually get 1/2" bar of standard bearing bronze from just about any bearing shop, not too bad for cost either.
Might be worth a try for you just to see and learn something new. Works for me.

Shame it will just sit on a shelf. 
My engines all have work to do in one form or another.

Even the old Atkinson sits on a bench at the entrance to my workshop as an interest factor when people come to browse.
Reconnect a battery and a quick flip gets it up and running , always with a favourable response.
There is nothing like an engine that fires up first flick.


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## retailer (Jul 10, 2019)

Having more experience than me you are probably right in that it is brass. I had that material already and the only bronze I have is some cast bar that once machined will be under 0.5",  to make some split bushes with 0.512" OD I would need the next size up from 0.5" - I'll probably leave the brass for now as they are already made, I plan to strip the the engine down after the first few runs to see how things are wearing maybe by then my father in law will agree to part with the only bit of his old boat he has left a 1" diam x 40" long bronze propeller shaft.

Yes it is a shame for working models to spend a good part of their life as display pieces, the only other model engine I have made is a Jenny Wren style mini steam engine I gave it to my adult son as a Xmas present and although it has been almost 2 yrs he has not as yet steamed it even though I packaged it up in a presentation box along with mini oil can and syringe to fill the boiler with, he says he does not want to muck up the polished appearance.


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## bluejets (Jul 10, 2019)

retailer said:


> he says he does not want to muck up the polished appearance.


Hehehe....good one.

Made patterns for my V8 some 3 years ago. Mate going back to the UK for holidays and expect I'll be generating some castings in his workshop's sandbox section some time soon after his return.


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