Author Topic: Compressed Air V8 Engine  (Read 52023 times)

Offline cfellows

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Re: Compressed Air V8 Engine
« Reply #30 on: July 27, 2012, 12:47:52 AM »
Thanks to everyone for the words of encouragement.

I managed to reclaim my shop from the missus who was using it to paint a large piece of furniture.  Here's 8 new connecting rods.  Not perfect but good enough.  I need to leave well enough alone or I'll wind up making a 3rd set! :hellno:



Next I think I'll give the pistons a go.  I'm planning on using steel since they will be riding in aluminum cylinders.

Chuck

« Last Edit: August 23, 2013, 09:44:58 AM by arnoldb »
So many projects, so little time...

Offline Dean W

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Re: Compressed Air V8 Engine
« Reply #31 on: July 27, 2012, 03:26:40 AM »
Good progress, Chuck.  Especially since you made enough con-rods for a V-16.  ;)
Everything is nice and neat in their trays, too. 
Dean
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Offline cfellows

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Re: Compressed Air V8 Engine
« Reply #32 on: July 27, 2012, 03:42:02 AM »
Thanks, Dean.  I picked that tray up at Harbor Freight for about $6.  It has 7, nice big compartments that keeps the parts from getting lost in the clutter on my workbench. 

Here is a picture of the first piston.  I decided to make them from brass since it's easier to machine than steel.



Chuck
« Last Edit: August 23, 2013, 09:45:15 AM by arnoldb »
So many projects, so little time...

chuck foster

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Re: Compressed Air V8 Engine
« Reply #33 on: July 27, 2012, 03:47:01 AM »
nice looking build chuck  :ThumbsUp:

only 2 sets of rods eh?  remember i am the king of re-making parts (9 cylinders for a 3 cylinder engine)  :ROFL:

looking forward to you next posting on this build.

chuck

Offline KB

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Re: Compressed Air V8 Engine
« Reply #34 on: July 27, 2012, 03:39:38 PM »

Cooking right along there Chuck!

I can't wait to hear what this one sounds like.

Offline DavidF

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Re: Compressed Air V8 Engine
« Reply #35 on: July 27, 2012, 05:26:08 PM »
Ok  im hooked on this thread as well, cant wait to see more!!

Offline cfellows

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Re: Compressed Air V8 Engine
« Reply #36 on: July 27, 2012, 11:30:56 PM »
Thanks for the encouragement David, Kevin, Chuck.  The folks on this new forum are a lot more engaged than the other forums. 

I got the pistons all made today.  Still need to drill the wrist pin holes, but other than that, they are finished.  I decided to make them out of steel rather than brass, mostly cause I hate using my brass, but also I figured the steel would wear better.  Turns out they weren't all that hard to machine.

I first cut 8 blanks from 3/8" OD drill rod.  The blanks are are about 7/16" long which is 1/16" oversize.  The first lathe operation after skimming the end is to drill a 1/8" center hole that is 5/16" deep.  This will leave a 1/16" thick top on the finished piston.



Next I used a 5/16" end mill to bore out the bottom 1/16" deep, forming the skirt.



Here's 7 of the pistons after drilling the bottoms...



Unfortunately I didn't take any pictures of the slot milling operation.  All I did was chuck each of the pistons in an ER20 collet chuck that allowed me to hold the piston vertically in my milling vise.  Then I made multiple passes with a 1/8" end mill to form the slot.  After milling all the slots, I then trimmed off the tops of the pistons in my lathe to bring the finished length down to 3/8"

Here's the finished pistons along with all the other parts I have todate.



Next I'll be figuring out the details of the valve and air supply assembly.  This could take a few days...

Chuck
« Last Edit: August 23, 2013, 09:45:44 AM by arnoldb »
So many projects, so little time...

Offline Dean W

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Re: Compressed Air V8 Engine
« Reply #37 on: July 27, 2012, 11:37:49 PM »
Pistons look good, Chuck.  I don't blame you for wanting to save your brass.  Gosh, it's gone through the roof, lately!
Dean
In beautiful N. Idaho, U.S.A.

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Offline swilliams

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Re: Compressed Air V8 Engine
« Reply #38 on: July 28, 2012, 03:14:44 AM »
Your really churning out the parts there Chuck. Looking good

Steve

Offline sbwhart

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Re: Compressed Air V8 Engine
« Reply #39 on: July 28, 2012, 07:18:23 AM »
Looking good Chuck you're certainly knocking the parts out with this one  :ThumbsUp:

Looking forward to the next bit.

Stew
A little bit of clearance never got in the way

Offline ironman123

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Re: Compressed Air V8 Engine
« Reply #40 on: July 28, 2012, 01:02:57 PM »
Nice going there Chuck.  Enjoying this build.

Ray
Ray
Central Texas

Offline NickG

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Re: Compressed Air V8 Engine
« Reply #41 on: July 28, 2012, 03:40:36 PM »
That's a lot of little parts! Great work there, enjoying it too.

Offline cfellows

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Re: Compressed Air V8 Engine
« Reply #42 on: July 28, 2012, 11:15:44 PM »
Thanks Nick, Ray, Stew, Steve, Dean.  Comments always appreciated!

A bit of an aside today.  Actually, building fixtures and improving the work area, all related to building this engine.

For the air delivery system, I'm using 3/32" brass tubing.  Because of the engine design, I'll be needing a 90 degree bend in each tube that will have to be pretty tight.  I have a nice tube bending set, but it won't achieve the radius I need.  So I set out to make  a special jig.

I needed to turn a 3/32" wide groove with a radiused bottom 3/64" deep.  So, I ground a semicirular (more or less) tip on a 3/32" cutoff blade.



Then I chucked a 3/8" diameter length of drill rod in the lathe and cut the groove.  Well, I actually cut two grooves because I originally planned to make a two-piece bending jig.  I later decided it didn't need to be that complex.



Next I milled an axial notch on the center line of the rod and silver soldered a rectangular piece of cold rolled steel into it.



Finally, I drilled a 3/32" hole though the cold rolled steel, positioning the drill bit in the groove in the rod.



To make the bend, I insert the tubing into the hole...



Clamp the jig into my bench vice and make the bend using my thumb





Chuck
« Last Edit: August 23, 2013, 09:46:37 AM by arnoldb »
So many projects, so little time...

Offline Dean W

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Re: Compressed Air V8 Engine
« Reply #43 on: July 29, 2012, 12:45:24 AM »
That's a handy tool, Chuck.  It makes a nice looking bend, too.  Thanks for showing that!
Dean
In beautiful N. Idaho, U.S.A.

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Offline AussieJimG

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Re: Compressed Air V8 Engine
« Reply #44 on: July 29, 2012, 01:17:39 AM »
I just love the way you build jigs and tools to do the job. And the results show the value of your methods. Thank you for showing. :cheers:

Jim