Author Topic: Compressed Air V8 Engine  (Read 54540 times)

Offline cfellows

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Re: Compressed Air V8 Engine
« Reply #60 on: August 03, 2012, 03:59:31 PM »
Very neat, Chuck :)

Is there a reason why you chose bearing balls over say a bearing roller for the valve? (Just thinking a roller  would give a better seal while still being hard and exact diameter)

Thanks, Bill, I used balls because they are generally more available.

Chuck
So many projects, so little time...

Offline cfellows

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Re: Compressed Air V8 Engine
« Reply #61 on: August 06, 2012, 08:15:37 PM »
I finished up the flared tubing connectors this morning. 



The female caps and the male part has an 8-40 thread on the flare end and a 5-40 thread on the smaller end which will screw into the crankcase.  There is a 1/16" center hole drilled all the way through



Both the female and male parts are made from 3/16" brass hex rod.  Chucking this small stuff in even a 3" 3-jaw chuck is troublesome and can come loose when trying to cut threads.  So, after noodling on it for awhile, I rummaged through my socket drawer and found a nice 3/16" socket with a depth that was suitable for my work pieces.



I used this to hold the male part for both threading operations and for drilling the 1/16" center hole.



I also used the socket to hold the female caps for chamfering the top end and cutting the bottom end to uniform length.

Chuck
« Last Edit: August 23, 2013, 09:50:27 AM by arnoldb »
So many projects, so little time...

Offline Dean W

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Re: Compressed Air V8 Engine
« Reply #62 on: August 06, 2012, 10:30:29 PM »
Chuck, using the socket is such a good idea!  Sometimes we read a thread just for the enjoyment, and sometimes
we come across a little lightning strike, like this one.  I hope I remember it!
Dean
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Offline cfellows

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Re: Compressed Air V8 Engine
« Reply #63 on: August 07, 2012, 05:03:50 AM »
Thanks, Dean, glad you found something you can use!

Here are the brass tubes that will deliver the air to each of the cylinders...



The top right tube with the flare cap fitting was the prototype.  I made 8 new tubes using a new tube bending jig I made which gives me a crisper bend.  The cap will be salvaged from the prototype to go on one of the new tubes.

Slow but steady at this point.

Chuck
« Last Edit: August 23, 2013, 09:50:54 AM by arnoldb »
So many projects, so little time...

Offline cfellows

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Re: Compressed Air V8 Engine
« Reply #64 on: August 07, 2012, 06:13:14 AM »
I thought I'd post some pictures of the new jig I made for bending the 3/32 brass tubing...

I started with this... it's turned from 3/8" drill rod and has a 3/32" wide, 3/64" deep radiused groove turned in it.  It's screwed to the aluminum block with a 10-24 SHCS.



This is clamped in my vise, about 5/16" down from the top of the jaws.



Next I place the brass tube into the groove in the bushing



... and hold it there while I slide a stop block between the bushing and the vise jaw.  The stop block has a 3/32" radiused groove in it so the brass tubing won't kink.



Then I take a second block, also with a 3/32" radiused groove in it and use my thumbs pushing on it to force the tubing around the bushing.



As the Brits would say, it works a treat!

Chuck
« Last Edit: August 23, 2013, 09:51:21 AM by arnoldb »
So many projects, so little time...

Offline arnoldb

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Re: Compressed Air V8 Engine
« Reply #65 on: August 07, 2012, 09:11:36 AM »
Good going Chuck; I also like the socket idea.

Did you have to anneal the brass tubing at all before bending ?

Kind regards, Arnold
Building an engine takes Patience, Planning, Preparation and Machining.
Procrastination is nearly the same, but it precludes machining.
Thus, an engine will only be built once the procrastination stops and the machining begins!

Offline swilliams

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Re: Compressed Air V8 Engine
« Reply #66 on: August 07, 2012, 10:03:43 AM »
That was educational Chuck. Nice to learn a little about miniature pipe work.
Steve

Offline cfellows

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Re: Compressed Air V8 Engine
« Reply #67 on: August 07, 2012, 03:27:03 PM »
Good going Chuck; I also like the socket idea.

Did you have to anneal the brass tubing at all before bending ?

Kind regards, Arnold

Thanks, Arnold.  I didn't anneal the tubing.  Don't know if it would have made it easier or not.  Turns out, the 3/32" stuff isn't very hard to bend, although my thumbs are a little tender this morning.   :)

Chuck
So many projects, so little time...

Offline cfellows

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Re: Compressed Air V8 Engine
« Reply #68 on: August 08, 2012, 09:06:09 PM »
Did some more work on the air inlet tubes today.  I made the flanges that will be soldered to each tube. 

I first chucked a length of 7/16" brass rod in the lathe and center drilled a 3/32" hole about an inch deep.  Than I used a parting tool to part off 9 disks, each .080" thick.  I made an extra one since I usually manage to screw up at least one.   :Doh:



After running each face over some 220 grit sandpaper to remove the flashing I clamped each one individually in my milling vice and milled opposing flats, resulting in a piece 1/4" wide and 7/16 long. 



Got one piece in the picture mocked up with the air tube sitting in the flange.  When soldered, the top end of the tube will extend through the flange by about 3/32" and extend into the head by that amount.

Next I'll drill the holes on either side of the center hole.  These will be used to screw the flange to the cylinder head.

Chuck
« Last Edit: August 23, 2013, 09:51:58 AM by arnoldb »
So many projects, so little time...

Offline ironman123

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Re: Compressed Air V8 Engine
« Reply #69 on: August 08, 2012, 10:11:22 PM »
Good going there Chuck.  Makes my fingers and wrists hurt just looking at those pictures.

It is all looking good.   :ThumbsUp:

Ray
Ray
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Offline zeeprogrammer

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Re: Compressed Air V8 Engine
« Reply #70 on: August 08, 2012, 11:28:41 PM »
Very interesting thread Chuck.

Thanks for the drawing of the plumbing...very helpful.

I also really liked the use of the socket head. That's given me some ideas I think I'll need in the near future.
Carl (aka Zee) Will sometimes respond to 'hey' but never 'hey you'.
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Zee-Another Thread Trasher.

Online steamer

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Re: Compressed Air V8 Engine
« Reply #71 on: August 09, 2012, 12:43:15 AM »
Nice tubing bender Chuck....I'll need that for the Wallaby build!

Dave
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Damned ijjit!

Offline cfellows

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Re: Compressed Air V8 Engine
« Reply #72 on: August 10, 2012, 10:46:28 PM »
Thanks Dave, Zee, Ray... That tubing bender does work nice.  You might pay particular attention to the little block that fits between the spool and the vice jaw.  I purposefull made it that size so it would be a firm fit... Didn't want to have to permanently fix it to the jig.

Got some more work done on the engine today.  I had kind of convinced myself not to make an oil pan for the crankcase, that I would just leave it open.  I like looking at the crank and rods and it also makes it easy to oil them periodically.  However, I decided the engine would look better if it had a pan, so today I got to work and made one.

I started off with a piece of 3/4" thick magnesium 3 inches long and 1.7" wide.



Here I've milled 3/16" of each side to form the bolt flanges for the screws which will attach the pan to the upper crankcase half.



Next I milled out the inside of the pan and rounded the inside edges along the sides.



Finally I rounded over the outside bottom edges.



And here's a picture of the two halves placed together.



Chuck
« Last Edit: August 23, 2013, 09:52:28 AM by arnoldb »
So many projects, so little time...

Offline arnoldb

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Re: Compressed Air V8 Engine
« Reply #73 on: August 11, 2012, 05:24:49 PM »
 :ThumbsUp: That looks a treat Chuck.

Kind regards, Arnold
Building an engine takes Patience, Planning, Preparation and Machining.
Procrastination is nearly the same, but it precludes machining.
Thus, an engine will only be built once the procrastination stops and the machining begins!

Offline sbwhart

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Re: Compressed Air V8 Engine
« Reply #74 on: August 11, 2012, 05:37:22 PM »
Looks good Chuck  :ThumbsUp:

Stew
A little bit of clearance never got in the way