Author Topic: Compressed Air V8 Engine  (Read 53072 times)

Offline rleete

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Re: Compressed Air V8 Engine
« Reply #150 on: August 25, 2012, 01:07:48 AM »
What kind of oil?

Offline cfellows

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Re: Compressed Air V8 Engine
« Reply #151 on: August 25, 2012, 01:21:54 AM »
What kind of oil?

Up to now I've been using 3-in-1 oil, but I'm going to switch to something a little thicker.

Chuck
So many projects, so little time...

Offline cfellows

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Re: Compressed Air V8 Engine
« Reply #152 on: August 25, 2012, 01:24:55 AM »
Here's another vido.  This one is several videos combined, with a small flywheel, no flywheel, a propeller, and one with the oil pan removed to show the rods and crankshaft.

http://www.youtube.com/watch?v=NSFASUx_NkY&

Notice the sound is amplified by the board it's sitting on.  I'm going to make a sound box to run my engines on.

Chuck
So many projects, so little time...

Offline rleete

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Re: Compressed Air V8 Engine
« Reply #153 on: August 25, 2012, 01:53:50 AM »
Yeah, that board really makes it sound much larger.

I knew it didn't need much of a flywheel to run!

Offline dvbydt

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Re: Compressed Air V8 Engine
« Reply #154 on: August 28, 2012, 10:06:31 AM »
Yes, looks like three mains are be enough for air loads - your video with no sump shows it running on centre main only!
That was a striking difference in sound when you lifted the engine off of the board, more experiments needed?

Ian

Offline KB

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Re: Compressed Air V8 Engine
« Reply #155 on: September 08, 2012, 06:53:41 PM »

Awesome work Chuck! and quick too.

I can't wait to see it all "packaged" up.

Offline cfellows

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Re: Compressed Air V8 Engine
« Reply #156 on: October 17, 2012, 02:37:30 AM »
Thanks, everyone, for all the kind words.  I've came down with a nasty cold after we got back from vacation and haven't been in the shop for two weeks or so.  However, I do have something to share with the group.

John McClelland had generously volunteered to make up some nice drawings for the engine just for the experience.  So, attached is a teaser, a full 3 dimensional drawing in PDF format for you to look at.  John will be providing a complete set of detailed drawings which we'll make available at no cost.

Chuck

PS... Thanks again, John
So many projects, so little time...

Offline Don1966

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Re: Compressed Air V8 Engine
« Reply #157 on: October 17, 2012, 02:49:16 AM »
Oh wow! Chuck you are the greatest, many thanks for the drawing and John too.  :AllHailTheKing: let us know when you get them in the download section. Hope your cold has eased off. Get well soon.

Don

Offline Hagar

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Re: Compressed Air V8 Engine
« Reply #158 on: January 02, 2015, 12:56:07 PM »
Hello.

I know it's been a long time this thread "died", but i discovered it a few time ago.

I've seen both videos and i fell in love with this engine incredible sound. Closer to a actual gas V8 than usual air device songs (pssshhhit  :Lol:). Thanks to spring balled head, it seems. Would it be possible to see pictures of these engine head, please ?
I mean, admission holes and parts hidden in...

I saw scheme on page 4. It's been a great help to understand. But i can't figure how spring can fight pressure when low dead point is reached, since there's atmo pressure behind balls and high pressure on the other side. Even if rotative valve is closed, high pressure remains, i think...

I'm on the verge to start studying my own, i must say. first hand drawings are already layed for a flat pattern and a one-piece connecting rod between two opposite cylinders.
Hope Chuck will allow me to use some of his solutions.

Offline cfellows

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Re: Compressed Air V8 Engine
« Reply #159 on: January 02, 2015, 04:56:57 PM »
Hagar,  I've attached a 3-page drawing which you may have already seen, but explains in some detail how the slave valve works.

I saw scheme on page 4. It's been a great help to understand. But i can't figure how spring can fight pressure when low dead point is reached, since there's atmo pressure behind balls and high pressure on the other side. Even if rotative valve is closed, high pressure remains, i think...

The ball valve is quite a loose fit in the passage, up to .010" clearance.  When the inlet valve closes, the residual high pressure air in the cylinder quickly escapes around the ball valve allowing the spring to push the ball back to the resting position.  This arrangement makes the strength of the spring important to the running speed of the engine.  A weaker spring is used for good low idle but limits the maximum speed.  A stronger spring increases the maximum speed, but also raises the minimum idle speed.  In general, for smaller engines, a spring with a wire size of around .010" - .015" works the best. 

My air valve design is completely open for anyone to use in their own designs although I always appreciate the mention of my name in published work.

Chuck
« Last Edit: January 02, 2015, 06:04:15 PM by cfellows »
So many projects, so little time...

Online sco

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Re: Compressed Air V8 Engine
« Reply #160 on: January 02, 2015, 05:23:05 PM »
That's interesting - wonder if I made my balls a bit too tight a fit in their passages as my engine never ran as well as Chucks.

Simon.
Ars longa, vita brevis.

Offline Hagar

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Re: Compressed Air V8 Engine
« Reply #161 on: January 02, 2015, 09:17:28 PM »
Thank you, Chuck.
Interesting pdf.

Of course, if i lead this project to the end, your name will appear.
Very nice of you to let us use your ideas.