# Starting a new engine



## Bogstandard (Nov 5, 2007)

When I saw the vid of Chucks pseudo hit 'n miss I was mesmerised by it and played it over and over again, and when Chuck gave a very good explanation of the poppet valve system I then decided that I must make one. I am not going into the full build, but just like the mine engine, snippets in time during the build.
When I start an engine I always make sure, if possible, to have the major bits to hand so that I know I won't be held up during the build, a sure fire way of a project finding its way under the bench.
Here is a pic of the basic materials for this project. I have a confession to make, I have already started on it. I had a lump of old rusty steel bar and before going any further I needed to know if it would be any good for the cylinder. It didn't turn out too bad, by the time I had got rid of all the holes and cross drillings in it, there was enough left to make a cylinder for an engine of 1" bore x 2" stroke. A real silk purse out of a pigs ear.







So the other bits are a plasma cutout aluminium 1/2" thick disc that should make the base, uprights and con rod.
Some gears that by machining and ganging will give me a 6 cycle engine.
The top end of a sash weight which will give me the piston, the loop from the top won't be thrown away, there is still a bit of cast in that just begging to be made into something.
A bit of SS rod out of an old printer, and some flanged bearings that I use for everything because I have so many I will be making engines for years to come.
The last bit nearly made me cry when I got it out of my stash, a lump of bar end brass to make a couple of flywheels. I don't know why it upset me because I got a load of it from the scrapyard, but it is just the thought of using it. I just might find a bit of replacement steel so I won't have to use it.
Now lets see if we can make an engine from junk, plus a little bit.

John


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## Bogstandard (Nov 7, 2007)

Right, here we go about how I go about making a new engine.
I always start with what I call a 'fag packet' sketch (in American that would translate into an empty cigarette packet being opened up and drawing on the plain paper interior), but in this case I have used a piece of paper. The drawings contain a basic prelim view of the engine with quick notes on it showing features that will be required to make the engine. Usually no dimensions are shown as this is a suck it and see (or winging it) build. So here is my sketch, not pretty to look at but it shows what I want.






This is as far as I have got at the moment, the cylinder is basically made, the piston is finished. When the piston is put into the cylinder with a bit of oil spread around, it takes nearly 30 secs for it to drop to the bottom, so I have a good enough seal to carry on to the next stage.






By the way, if this engine works as well as I hope, I will build another but using materials for running on air only, and no races.
It should make an ideal beginners project. (Shred please take note)

John


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## Bogstandard (Nov 9, 2007)

Now I am starting to design and make things, but still winging it.
Marv would say, 'all this could be drawn up and everything calculated to get the angles correct, and made from those drawings'. I don't work like that, it is too slow for me and also geometry isn't my forte.
So here is where I am up to.






I want to fit roller bearings into the big and little ends, so a machined one piece crank can't be used, so I have gone for a built up one, with one of the crankpin ends left floating to allow disassembly for bearing fitting, I might put a bolt thru it or just leave it floating, it depends how the flywheel standards turn out, and if they are rigid enough to allow for a floating pin or not. That is a go back to it job as the engine progresses.
To give you some sort of scale on this engine, the conrod is about 4.5" long by 3/4" high by 1/2" thick, so this is no small engine. As you can see it has been roughed out on the bandsaw and is now ready for machining, all on the miller, no lathework on this rod at all.
The holes are in fact finished to size for fitting bearings, but treated in different ways. I always like a bit of force fit for my bearings when going into ali, so the large hole was just brought up to 1/2mm undersize then the 13mm drill was very quickly wacked thru the hole in one hit, to leave behind a very rough surface. This gives me the interference fit I am after.
The smaller 10mm hole was finished in a different way, the hole again was brought to 1/2mm undersize but then a 10mm hand reamer was fed in from either side until it only just protruded from the opposite side. This gives a slight taper going into the centre of the hole, because unlike machine reamers, hand reamers have a tapered lead in and I use that to my advantage. The further the bearing is pushed into the hole, the tighter it gets, and I am using two bearings, one inserted from each side.
Nice tight fits all round.

John


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## cfellows (Nov 9, 2007)

The valve I used in the video, although functionally the same, is physically different.  Hopefully you can see in the pictures below how this other, inline arrangement works.  The view is from the top.  The first picture is with the poppet valve closed, so the air is free to pass from the cylinder to the exhaust.  The second picture is with the Poppet Valve Open, which pushes the small blue piston valve down, closing off the exhaust port, and exposing the inlet port to the cylinder. 

Although this valve arrangement is more elegant, it's much harder to keep air from leaking around piston valve when "firing".  So, you tend to get a lot more air noise and the engine consumes more air when running.






Chuck


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## Bogstandard (Nov 9, 2007)

Chuck,
Many thanks for making the effort to explain it to me. It is a more compact unit.
I will be going with your original solution to the inlet and exhaust system, mainly because it will allow me to have a remote poppet valve, as shown in my rough sketch and allow me hopefully to have a scale looking speed control, I suppose that I will have to have a slightly different timing on the cam to allow for the connection pipe from the remote poppet to the engine.
What do you think of the bore/stroke ratio that I am planning, 1" bore, 2" stroke. My reasoning for this is to give a slower running engine, and is the same ratio as I use for my live steam engines.
Can you give me any pointers towards spring pressure on the sliding piston, it would save me a lot of time in experimentation if you could.
As I have said before, your engine totally fascinated me. 
If this one is a success I am hoping to scale it down and make it a little easier to make, then present it as a build package on this site to give the beginners a chance of making a copy of your great little engine.
Again many thanks for your input.

John


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## cfellows (Nov 9, 2007)

A 1" bore x 1.5" stroke would be more in line with the ratios I typically use for a slow running engine, but a 2" stroke should work fine too, if you don't mind the amount of air it will use to run it.  The engine in the video has a 7/8" bore and probably about a 1.25" stroke.

Spring pressure on the sliding piston is pretty light, something with a wire size like a retractable ballpoint pen spring.   The sliding piston fit should be a loose enough fit that the spring can return it to the home position once the poppet valve closes.  I'd use a 1/4" or maybe even 5/16" diameter port for the sliding piston valve.

By the way, there are two more engine videos on my website now that use this same poppet valve arrangement.  The 2 cylinder horizontal engine is a "4 stroke" version, and the 1 cylinder vertical is a "2 stroke" version.

Chuck


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## Bogstandard (Nov 9, 2007)

Chuck,
You've done it again and saved me hours of development time with that spring and piston info.
I think you must make engines the same as I do, make and modify as you go along. You end up with some very interesting engines doing it that way. And of course you will understand more than most how much a little bit of info like you have given me shortens the development time, plus less bits to remake over and over again trying to find the right solution.
I looked at your other engines, absolutely wonderful, and unique. I just hope mine runs as well as yours do.

Many thanks

John


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## cfellows (Nov 9, 2007)

Bogstandard said:
			
		

> I looked at your other engines, absolutely wonderful, and unique. I just hope mine runs as well as yours do.



Thanks, John.  Luckily, these engines are pretty easy to get running.  Most of the twiddling is to get the right exhaust note with the least amount of air.

You have a couple of interesting feature on your drawing.  For example, putting the poppet valve back by the crankshaft is something I hadn't thought of.  Also, the "carburetor" speed control is a cool idea.

I generally put the poppet valve in the head, but that just because I'm trying to simulate the layout of a gasoline engine as close as possible.  Can't imagine why your arrangement wouldn't work just as well.

You can also vary the speed of the engine with an inline pressure regulator.  It gives a little bit different running characteristics and the exhaust note is a little softer.

The nice thing about this type of valving is that it works about the same on virtually all engine designs - singles, twins, inlines, v-engines, radials, etc.  The other nice thing is that it only requires one cam lobe and push rod.

On a future model, I want to use an impact valve motion instead of the standard cam configuration.  The new model will use a spring loaded push rod that will be pulled back by a spiral shaped cam.  When the push rod is pulled fully back, the cam will release the push rod and spring pressure will "fire" the push rod into the valve stem, like an airgun.  This will open the intake valve much more quickly, but then also will shut much more quickly.  I'm hoping this action will more closely simulate the combustion of fuel in the cylinder by using a lower volume of air at a much higher pressure.

Chuck


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## Bogstandard (Nov 10, 2007)

Chuck,
The reason for the remote poppet valve is that if a beginner was building the engine it would give him a chance to move it around to get it to fit as he might not be able to use the same gearset as I will be using. It won't be to 'scale', but it would solve the problem.
With reference to getting the engine sounding 'right'. I too like to have the exhaust note correct if possible.
This is a little idea that I came up with a couple of weeks ago and it does work well, plus it is very easy to experiment with to get the right sort of sound.
http://freeforums4u.com/viewtopic.php?t=536&mforum=homemodelengine

Used it to good effect on my mine engine

[ame]http://www.youtube.com/watch?v=76FAAv-PB78[/ame]

It just might work on yours, and it only takes a few seconds to try out.

John


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## Bogstandard (Nov 10, 2007)

Got a little bit more done today.
So here are a couple of pics which also demonstrate a couple of tips.






This first one shows one of my tips that I used on the pipe flanges, but for a different use this time. To set up for machining a taper on the conrod.
All I did was mark up the conrod with the taper I want, and by swapping and changing different sized rods or drills in the two holes I got the line parallel with the top of the vice jaws. Used in conjunction with a back stop, once one side was machined it was just flipped over, pushed up to the backstop and tapped down onto the jaw tops and the second side was machined. Perfect symmetry on the conrod.






Here is the finished rod after a couple of hours work.
But it is the flywheel blanks in the background that are the source of the second build tip. You will notice on each of them at the centre is a small machined boss, sitting on top of the main central boss, it is only 10 thou thick but is a major contributor to less friction in these engines we build.
If the flywheel, or in fact any rotating part is against a ball race or a plain face, this boss ensures that the friction is reduced by only having a small surface area in contact. Also if used against a ball race it makes sure that only the centre part of the ball race is being turned.

You will notice that there is an item missing, the crankshaft. That has been consigned to the recycle bin. The reason being is that I am taking Chucks advice and going for a shorter stroke, 1.5" instead of 2". It will only take an hour to make a new one.
But it does go to show that asking the right questions and taking advice when it is given makes building these engines a lot easier.
By using the info Chuck has given me has most probably shortened the build by about a week.

John


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## deere_x475guy (Nov 10, 2007)

Bogstandard, great looking engine there.  I really admire you guys that can take what you have and design, build a working engine.  Heck like I said I still don't have on that runs yet.  I did get a good ways on the cam for the Edwards Radial 5 and will post pics of that in another thread.  Keep the pics coming...))


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## cfellows (Nov 10, 2007)

John, I love that connecting rod.  You really do very nice work.  Can't wait to see more...

Chuck


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## rake60 (Nov 10, 2007)

That connecting rod looks very authentic.
It looks like a highly polished cast rod.
Amazing work!

Rick


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## Bogstandard (Nov 11, 2007)

Thanks for the good comments lads.
There is a reason for doing this profiling to a con rod. If you just had flat sides, in ali it is in fact a fairly weak component. By adding a curved profile to it the rod will in fact be a fair amount stronger. It is a clear case that goes against logical thinking, removing metal to make the item stronger.
There were no special jigs or angle pieces used in its making, just a couple of rods as shown in the first pic for doing the side angles, a 1/4" roundover bit, a 1/4" bullnose bit and a standard endmill. The main bits to making something like this are, the backstop, and machining the component in the correct sequence so that you can still hold it safely to carry out the next sequence.
Eventually, when I get some free time, I will do a little series on how easy these things are to make without any special jigging.
By the way Rick, if you give it a good dose of course grit blasting and painted afterwards, it would look just like a real casting.

John


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## Bogstandard (Nov 11, 2007)

I would just like to add something because of a thing that Bob said.



> I really admire you guys that can take what you have and design, build a working engine



MOST engines consist of a cylinder, piston, rod and crank.
The only major difference between any of them is how the power is got to the top of the piston, everything else is just basically the same.
So there are no mystical spells or alchemy to building an engine, just a few basic rules.
Once you can get these under your belt, plus a bit of machining experience to make the basic parts it is well within reach of everyone.

I would prefer rather than somebody praising me for doing something, to ask how it was done. That way you could learn how to do it as well.
Something like 'Hey John, nice conrod, can you tell me how you put the tapered profile in the side'.

John


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## gilessim (Nov 11, 2007)

I was just looking at this post and wondering exactly how you did that gouged out bit on the sides John, it doesn't look like you just tilted it in the milling vice with a ball end cutter ,or did you?


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## Bogstandard (Nov 11, 2007)

Giles,
That is basically the process but you need the fixed stop as a reference. Basically you start off with a slight uplift on the end you want to go deeper and wider. Lift the cutter slightly and look to see if it is anywhere near to the same taper as the outside faces, if not, just raise the end a bit more, I do it with a small wedge, bring your cutter down again into the narrow end until it just touches and take another cut. Repeat this until you have a tapered slot that matches with the outside edges. All I do then is just mark my little wedge, flip the job over, put the wedge into the mark and do your cuts to get down to depth. It really only takes minutes and gives a very good rendition of casting. 

Hal, 
Maybe I should have worded it slightly differently.
Your final sentence says it all.

John


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## Bogstandard (Nov 12, 2007)

Cookin' with gas now.
Managed to get a pair of flywheels to the roughed out stage, just need a bit of file work to blend everything together, then a quickie polish and they will be finished, but that bit comes later, get it running first then bling it up. Why waste time on something if it won't run.
The first one took over 3 hours, but once I had got all the co-ordinates the second took less than half that.






This is a shot of the new 3/4" throw crank, it looks a bit out of wack because the top right hole is free, this will allow it to be used with ball races, the rods on the sides will be trimmed to fit once the upright plates are made.






Now the basic parts for the engine are made, so it is just a matter of getting them into the correct positions to each other, plus it must also look right. So tomorrow it will be a bit of ali platework.






This is what I was on about a few posts back. Once you have the basic engine configuration, then make it into whatever you want.
Just imagine it as either a horizontal or vertical, steam or gas engine. This basic design could be used for any of those. It is just a matter of putting the right bits on.
The difficult bits now start, because I have never made a poppet valve system so I am working in the dark, thank goodness for Chucks info.


John


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## 1Kenny (Nov 12, 2007)

So thats how you put the relief in the rod. My simple mind couldn't figure it out. :? 

Kenny


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## Bogstandard (Nov 12, 2007)

Kenny,
I think I have said this before. Machining isn't at all difficult, it is just a matter of thinking how to do it.
Now you have read the post, and everyone else who has read it as well will have no problems making these tapered recesses. By the way it doesn't work with a normal cutter (unless you do a more complicated setup), or if your depth goes deeper than half the cutter width at the wide end. If that happens, you need to go to the next size up ball end mill.
I tend to shy away from complicated machining methods and usually just stick with a few special shaped cutters to get to where I want. In fact the flywheels were made with a 3mm and a 1/4" slot drills on the RT and on the lathe just my profile tool and a special tool that I ground up specifically to make the recesses in the flywheel.  I have many hundreds of tool bits that I have tried over the years, but I still come back to a basic few. So you most probably don't need a lot of the 'special' cutters that are available, just go back to basics and use the basic ones to their full potential.

Easy way out John.


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## cfellows (Nov 12, 2007)

John,

Do you just leave the one side on the crankweb free?  Do you use a pin or setscrew to secure it?

If you have any other questions, don't hesitate to ask.  Can't think of anything else you should know about the poppet valve.

Chuck


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## Bogstandard (Nov 12, 2007)

Chuck,
To see if the crank needs to be pinned for that one free hole, you need to have the side support plates and bearings in position. I use a lot of ball races and so after fitting two races each side of the crank I don't envisage it to flex, but if it is going thru one bearing or plain bushes I would definitely drill and tap thru the crankweb to hold everything rigid, but still be able to be dismantled to replace the ballrace if necessary.
Basically it is exactly the same as the setup on your engine, but putting a takeoff drive to the other flywheel from the crankpin sticking out from the side of the big end bearings.
What this method does is allow you to have a raced or plain bearing big end without having all the hassle of making split bearings.

'Clear as mud' he replies.

John


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## Bogstandard (Nov 18, 2007)

Not much to show for a couple of days work, but I have managed to get the basic platework made and the engine bits bolted to it.
It turns over nice and easily, so I don't envisage any problems getting it to turn over with air input.







This platework is not finished yet. What took the time was matching the fluting on the straight sides of the baseplate using the miller, to the fluting that was put on the curved ends on the lathe. 
Just a bit of holographic engine turning on the top of the baseplate plus some profiling to the uprights should see them finished.
So that is the basic engine completed, now to get onto the bits that will make it come to life.
This is where the thinking bit comes in, and the data supplied by Chuck.

John


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## cfellows (Nov 20, 2007)

John,

How did you fasten the cylinder to the pedestal and base, long screws from the bottom?

Chuck


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## Bogstandard (Nov 20, 2007)

Chuck,
Single recessed screw in the column into the meaty part of the cylinder, then two short screws from underneath to hold it to the baseplate. Doing it that way when lining everything up the cylinder and columns are one unit, and only the short screws are used to align everything.

John


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## Bogstandard (Nov 20, 2007)

I was hoping to have this engine finished to a running stage this week, but my body has said otherwise, I can hardly walk to the workshop never mind use the machinery. So this has been put on hold for a bit.
What I am going to try and do is sort out a few easy hints and tips while I'm chairbound, just to keep me active.

John


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## Bogstandard (Nov 22, 2007)

Right, slightly mobile again, and managed to get a few hours in today.
Over the years I have amassed large quantities of allsorts, including gears, never throw them away, have you seen the price for them nowadays.
Anyway, back onto the subject in question. I am going to try to get this engine to 'fire' every fourth full stroke, and if I am very lucky and careful with my timing, and by using a remote poppet valve that hopefully will give a slight delay before the air hits the cylinder, it just might run in reverse as well.

So here is the first pic.






The same thing as the hunks of junk on the left, with a couple of other bits of metal were turned into the gear setup on the right for my 4 to 1 gearbox. You will notice on one a bit sticking up. Instead of making a proper cam, in this situation I only need a striker to give a little nudge, so a bit of silver steel soldered in will do the job.






This is how my gearbox assembles. There are no holdown nuts, just pins stuck into the ali backplate, with spacers underneath the gears to put them at the correct height to each other. The gears are prevented from falling off their spindle by the flange on the little input gear and there will be a striker plate over the bottom gear.
No fancy footwork on this gearbox, just put the first little gear on, push the second one up to it with the spacer underneath, and using a transfer punch, dot thru for the pin location, then the same for the bottom gear. Ended up with a free running gearbox with negligible backlash.

A little bit of progress at last.

John


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## cfellows (Nov 23, 2007)

Lookin' good, John.  Have you decided where you are going to put the valve assembly?

Chuck


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## Bogstandard (Nov 24, 2007)

Hi Chuck,

I want to make the engine look 'busy' so I am going for a more complicated setup than is really necessary. The striker plate assembly is going to be mounted on the square face to the left of the cam gear.
To make it totally simple I could have used a very small pneumatic microswitch operated directly from the cam pin instead of a striker mechanism and poppet valve.


John


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## wareagle (Nov 24, 2007)

Bog, I have been watching this build and am very intrigued with the timing mechanism and valving.  I am eagerly awaiting seeing the final product!

I also like the shape of the base and the way you have mounted the cylinder.  It isn't anything complicated, but it is different from the usual square base that is typically used.  Very nice!

Thanks for taking the time to share your ideas and progress.  Your works are an inspiration!


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## Bogstandard (Nov 24, 2007)

Wareagle,
I try to do nothing that the average engine builder can't do with the equipment they already have.
Maybe where I am different is that I will sit in my workshop for hours just doing nothing other than looking for easy ways to produce something that looks different, and planning a procedure for making it, then just noting it down on a scrap of paper.
The base was made like this - cut a disc, using friction turning and cutting from the chuck side (to hide the centre drilling under the plate). Just using a profile tool and a standard turning tool. Then wacking off (with bandsaw)the two sides after previously marking the plate to width from a centre line. 
Then into the miller to clean up the edges. Then mounting the plate horizontally and using a round nose cutter, mill out to match the curved groove from turning, and then with a standard end mill match up the square cuts. Simple but effective, BUT if done in the wrong sequence could be rather difficult. Only four basic cutting tools used.
Why make life difficult when there is usually an easier way.

John


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## wareagle (Nov 24, 2007)

Bog, I am with you on the "keep it simple" concept.  This is where "vision" pays off!  You have it, and it inspires me (and a lot of the others) in the things I (we) do!

Thanks for sharing!


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## Bogstandard (Nov 25, 2007)

What a crappy day today.
Thought I would start on the poppet valve, so opened up the shop and saw the engine sitting there with the extra bits of the crankshaft sticking out of the sides. Will trim them to length, thinks I, disassembled the engine, stuck one bit in the chuck to part it off and 'bang'. I had forgotten about the crankweb and it hit my toolpost, effectively turning the crankshaft into a banana, but not tasting as nice. Spent today making another straight banana and a vid.
So here goes. Sorry about the quality of the vid.

[ame]http://uk.youtube.com/watch?v=mMWYomG6UG8[/ame]


John


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## cfellows (Nov 25, 2007)

That's going to be a great running (and great looking) engine.  Can't wait to see it finished!

Chuck


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## Bogstandard (Nov 26, 2007)

Finally got around to the bit that this engine is all about. It brought back memories of my foray into ic engines, the valve for it was just like the ones I used to make.
Here is a pic of the bits that go into a poppet valve, nothing special at all. Just a bit of carefull drilling and using a good quality 90 deg countersink bit to make the valve seating face in the block. The pic behind is my rough working sketch to make the drillings and as you can notice the block isn't machined all over, just enough to hold it in the correct position in the miller, why waste energy. Also notice that I have blued the block and rough marked what parts of the block I want to machine away to make it lighter and better looking. The outside machining is all done by eye.






About an hour later, the block has been tidied up and profiled. Just the end cap to make, two mounting holes to drill and a bit facing off the bottom to get it to the right height to the centre line of the cam follower.






I hope that this post and the previous one about the cam and gear setup has gone a long way to explaining how the air is fed to the top of the cylinder.

Once I have the cylinder head done (next job), I can lash up the air delivery to see if I need to make any changes before proceeding any further.

John


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## rake60 (Nov 26, 2007)

John I have several sketches of engine idea laying around in the piles
of papers in my shop.

I've never once tried to turn any of those sketches into an engine.
Watching yours come together is giving me the idea that I should at least
give it shot...

Very interesting thread!
I'm always looking forward to the next progress post.

Rick


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## Bogstandard (Nov 26, 2007)

Rick,
It isn't rocket science. If I can do it, I am sure you can.
You have the basic understanding of engines, just take it from there.
This one is only coming about because of that one I saw of Chucks.
Mine will operate in exactly the same sort of way, just a few things in different positions. So basically I have stolen his design, and modified it to suit my way of making things. I am even using his method of making a poppet valve, if I was going to design my own I would most probably used a striker pin lifting a ball bearing off its seat, but why not use a proven design.
Just start with cylinder, piston, rod and crank and go from there.
If it doesn't quite work as expected you can always recycle it.

John


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## Bogstandard (Nov 30, 2007)

I moved this across from the old site so that there was a bit of continuity to the post.

After beating my head against a wall, I actually cured a problem I thought wasn't there. Not having any specific dimensions to work to I just made the head with its sliding piston to what I thought it should be. But the engine wasn't as free as it was before I put the head on. To cut a long story short, I was preventing the cylinder from breathing correctly to atmosphere on the unpowered strokes by having the holes too small, 4mm diameter. I opened it up to 5mm and put a secondary exhaust port in and this is what I got. 

[ame]http://www.youtube.com/watch?v=30tFCnAuBnc[/ame] 

Grinning John


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## tattoomike68 (Nov 30, 2007)

I will update the how to post a video thread.

we have a youtube button in the post window now.
	

	
	
		
		

		
		
	


	





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[youtube=425,350]30tFCnAuBnc[/youtube]
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[youtube=425,350]30tFCnAuBnc[/youtube]


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## Bogstandard (Nov 30, 2007)

Great Mike,
Starting to make myself at home, just need to get the bed in.
Are there any limitations on pic size and quantity, just in case I have to resize before posting. I have been setting my pics to 8" by 6", don't understand them pixelly doodahs yet, will that still be ok.

John


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## tattoomike68 (Nov 30, 2007)

Bogstandard  said:
			
		

> Great Mike,
> Starting to make myself at home, just need to get the bed in.
> Are there any limitations on pic size and quantity, just in case I have to resize before posting. I have been setting my pics to 8" by 6", don't understand them pixelly doodahs yet, will that still be ok.
> 
> John



The pictures should *auto resize * to an 800 x 800 max. I dont thing you should have any problems at all about size. we can adjust that max size in the admin CP

I try to make my images 640 x 480 pixels, thats a standard web page size.


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## Bogstandard (Dec 2, 2007)

When I got this engine running and took a vid of it, then said that I was going to run it every second stroke rather than every fourth, something that Rick said (and now lost in the transfer over to the new site) stuck in the back of my mind, and that was how I should leave it as is.
So, thinking cap on, meddling fingers to work and have come up with a possible solution.
If I could change the gears over in a couple of minutes and do a quick retime on the little crankshaft gear, it should be possible with a little bit of remachining to existing bits to get it to run on 4th, 2nd and every stroke.
So I have made a set of very accurately machined gears where all the cam pin holes are on the same PCD.
So here is where I am up to.


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## Bogstandard (Dec 6, 2007)

Oh! No, not another pic of an unfinished engine.






But this does prove that sometimes I do a bit of work in the shop, rather than annoying everyone by moderating posts.
As you can see, I have silver soldered the hardened pins into the gears that I made, the 'nose' on the cam follower will get a bit of case hardening just to stop it wearing away.
The way it works is as shown on this vid.

Oh! No, not another vid of an unfinished engine

[youtube=425,350]EFfm9L90Tyw[/youtube]

For those who can't see the vid, here is the link.
[ame]http://www.youtube.com/watch?v=EFfm9L90Tyw[/ame]

This engine is now going to be sent away to the Bling Fairies and hopefully will be back in time for Christmas.

John


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## JohnS (Dec 6, 2007)

Hello John

I want one !

JohnS


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## Bogstandard (Dec 6, 2007)

John,
Hopefully when this one is finished, I will be making a basic version and written up like my little book, so you just might get one after all, but you will have to make it yourself.

John


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## cfellows (Dec 7, 2007)

The engine looks great, John. I love the modular approach where bits can be changed to alter the number of strokes, etc. It should be great for beginners, as well, since it let's them built it one section at a time. With the valve, head, and cams all separate from each other, it keeps things a lot simpler. Also gives it a more sophisticated look, in my opinion. 

I think you've come up with a revolutionary approach to engine building. You can change the cam arrangement, or the valve type, or the head without affecting the rest of the engine.

Chuck


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## Bogstandard (Dec 7, 2007)

Glad you like it Chuck.
As you can see I have tried to keep it simple, but get a fairly complicated engine.
Looking at it now, without bling, another one could be done in about 14 days, taking it easy.

John


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## Powder keg (Dec 7, 2007)

You could add a second valve on the other side and make it double acting? Nice engine. How is the throttle response?

Wes


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## Bogstandard (Dec 7, 2007)

Wouldn't be able to make it double acting because of the piston/conrod/crank layout.
The throttle response is very good on the 2 and 4 pin cams, but not as good on the single, but hopefully that will all be sorted when the bling fairies are done playing with it.

John


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