45 Degree V8

[dvbydt]

Thanks for that V/Line reference, it was very interesting. You have some real chunky locomotives in Aus. Those turbocharged, uniflow two stroke diesel are huge!

So, I may have to paint my little engine green (Google image) :-

http://www.google.co.uk/url?sa=i&source=images&cd=&ved=0CAUQjBw&url=http%3A%2F%2Fwww.johnsern.com%2Fmateriell%2Fdi3%2Foversikt%2F567.jpg&ei=l-wFVcKtOderaavrgtAE&psig=AFQjCNE-Mgv0Ye-DvTGMMhPV8jU4FG_i9A&ust=1426538008057220


Ian

[Hagar]

Congratulations !
Beautifull engine you made here. And the 45° angle idea seems to be a very good one.

On the first post, you told you tried Chuck Fellows's spring pushed ball system but it didn't work.
Did you understand the reason why ?

As i began my own air engine using the same system, i'm worried...

[dvbydt]

Hagar,

Chuck Fellows always gets them to run.   I may have bent the rules too far ( spring tension, ball size and port diameter) to succeed. As Douglas Adams said in the "Hitchhiker's guide to the Galaxy" Don't Panic! All models usually need a bit of tweaking to get them to run how you want. You have designed and made a very competent, interesting engine - perseverance wins eventually.

To answer your question on oiling, you can fit a small airline lubricator or just squirt some light oil into the intake occasionally.

Ian

[Hagar]

Thank you for your answer.

Mine is close to first start.

Your engine is very pleasant to my eyes.
If you do other video or pictures of it, i'd be glad to see them to steal your best ideas.

[Roger B]

It's not stealing your best ideas, it's called research 

[cfellows]

Congratulations !
Beautifull engine you made here. And the 45° angle idea seems to be a very good one.

On the first post, you told you tried Chuck Fellows's spring pushed ball system but it didn't work.
Did you understand the reason why ?

As i began my own air engine using the same system, i'm worried...

There are a couple of things that help get the engine to run.  First, the ball valve must be a really loose fit, .010" is not unreasonable.  Second, the spring should be pretty weak and just long enough to hold the ball closed, no longer.  My springs are usually made of .009" wire.  These parameters will allow the engine to idle pretty slowly and run moderately fast.  For higher speed, the spring needs to be a little stronger, but not too much.

Chuck

[dvbydt]

Hagar,

We all bring something to the party on this forum and imitation is supposed to be the most sincere form of flattery. You even get THE man giving you guidance on your valve setup!

Ian

[Hagar]

I must say i'm proud.
And lucky since it started.

Setup is as chuck said. Springs come from eight "Pilot super grip" pens i bought to pick them up.

[dvbydt]

Hagar, very pleased you got yours to run - looks good! What are you going to try next?

Well, centre main has been added, the air in and the exhaust systems tidied up. The chain drive has been replaced by a small toothed belt.
(The NSU drive system worked but because the torque for the cam was high, it was too small to take the loads. If I build a bigger engine, I might try it again.)
It runs at about 1,100 rpm from 100 down to 20 psi but because of the free vented exhaust system, it consumes more air than I had hoped. I will work on a revised system.

Ian

[dvbydt]

This engine is now finished

The exhaust system has been revised so as not to use so much compressed air and it will now run from 120 to 1600 r.p.m. It much prefers high pressure with flow restriction for slow speed. With luck I should be able to get videos done over the weekend. Eight pulses per rev makes it very smooth running and it doesn't
move over the table whilst running!

Ian

[dvbydt]

Finally managed to upload two videos onto Youtube. Here are the locations :-

<a href="https://www.youtube.com/watch?v=8ysh0kwC6mw" target="_blank">http://www.youtube.com/watch?v=8ysh0kwC6mw</a>

<a href="https://www.youtube.com/watch?v=yXgaZM_b9iE" target="_blank">http://www.youtube.com/watch?v=yXgaZM_b9iE</a>

The view of the camshaft is a slow motion video showing the inlet and exhaust PEEK followers.

Only final fine tuning of the camshaft timing to do then I can call it FINISHED!

Ian

[vascon2196]

Great job!!!

[Roger B]

That's a nice runner   

[dvbydt]

Just in case I gave the impression that all my designs work first time - here are some of the camshaft failures

And the teaser for the crankshaft of the single cylinder engine I promised to detail. (Just to show I am working on it)

Thanks to all who showed an interest.

Ian