Author Topic: Smaller Horizontal IC Engine - 5/8" Bore  (Read 28102 times)

Offline cfellows

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Re: Smaller Horizontal IC Engine - 5/8" Bore
« Reply #30 on: October 18, 2014, 06:17:19 AM »
Well, instead of sitting in my recliner in front of the laptop all night, I spent some more quality time in my shop making the cylinder. 







It looks a little chunkier than I had thought it would, but it'll do for now.  The bore is only 0.625" but I left enough meat around it that I can bore it out to 0.750" if I need to.  So, perhaps tomorrow I'll get on to the head.

Chuck
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Offline Roger B

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Re: Smaller Horizontal IC Engine - 5/8" Bore
« Reply #31 on: October 18, 2014, 09:00:41 AM »
Looking good  :ThumbsUp:  :ThumbsUp:

How do you support the crank webs when you are turning the shaft?
Best regards

Roger

Offline cfellows

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Re: Smaller Horizontal IC Engine - 5/8" Bore
« Reply #32 on: October 18, 2014, 03:58:02 PM »
Looking good  :ThumbsUp:  :ThumbsUp:

How do you support the crank webs when you are turning the shaft?

I wedged a 1/4" tool bit and a shim that was a tight fit and the pinching action of the two centers held them in there.  Not very precise and a precision made clamping device would have been better.

Chuck
So many projects, so little time...

Offline Don1966

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Re: Smaller Horizontal IC Engine - 5/8" Bore
« Reply #33 on: October 18, 2014, 03:58:19 PM »
Go ahead with you self Chuck, you don't mess around do you? I had just check on your progress and now you have crank and cylinder done. Very impressive bud................ :ThumbsUp:


 :popcorn:
Don

Offline cfellows

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Re: Smaller Horizontal IC Engine - 5/8" Bore
« Reply #34 on: October 18, 2014, 11:30:18 PM »
Thanks, Don, I've had a burst of enthusiasm for the past week or so.  Hopefully it'll last until I get it finished...

Today I made the cylinder head.  I started with a piece of cast iron, turned it down to 1.5" and  shouldered down the outboard end to 15/16".  Then I reversed it in the chuck and drilled it through the center with a 9mm bit.  I  cut a 5/8" diameter, 1/4" deep recess in the bottom side for the combustion chamber.  I mounted the piece on my rotary table and drilled and counter bored the 6 holes for the head bolts.  I drilled and tapped a 1/4" model pipe taper in the side for the intake and exhaust.  Finally, I tapped the spark plug hole 10mm x 1mm.   Here's the finished product.







Next I got started on the piston.  It's 5/8" diameter and 1" long. 



However, I need to finalize the design of the connecting rod before I finish the piston.

Chuck
So many projects, so little time...

Offline b.lindsey

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Re: Smaller Horizontal IC Engine - 5/8" Bore
« Reply #35 on: October 19, 2014, 12:39:30 AM »
Wow Chuck...I missed a couple of days and you have made a huge amount of progress. I like the use of the angle iron for the base sides but how is it to machine?

Bill

Offline Bearcar1

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Re: Smaller Horizontal IC Engine - 5/8" Bore
« Reply #36 on: October 19, 2014, 02:17:47 AM »
N-I-C-E !! going Chuck. Boy, a great deal of progress has been made. I like seeing the pictures to document your project. That sure is going to be a pretty engine when you are finished (are they ever *really* finished ?)  :P   Great work..


Offline cfellows

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Re: Smaller Horizontal IC Engine - 5/8" Bore
« Reply #37 on: October 20, 2014, 02:34:01 AM »
Only one picture today...



I finished up the piston and connecting rod today.  I used my CNC mill to cut out the connecting rod.  Had to file off some of the edges where it was interfering with the end of the cylinder.  Will probably have to clean it up some.

Chuck
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Offline cfellows

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Re: Smaller Horizontal IC Engine - 5/8" Bore
« Reply #38 on: October 20, 2014, 06:38:50 AM »
A few more pictures with the beginnings of a flywheel...







The flywheel rim in the picture is the remnant of a cast iron flywheel from a previous life which had some broken spokes.  It's about 5.25" diameter which is quite large for this size engine, but it's just what I wanted.  I'll mill a spoked flywheel center from aluminum and heat shrink it into the cast iron rim.  As they say, waste not, want not...

Chuck
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Offline cfellows

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Re: Smaller Horizontal IC Engine - 5/8" Bore
« Reply #39 on: October 21, 2014, 03:07:13 AM »
Got the center section of the flywheel done today.  I drew up the design in Visio, processed it with CamBam, then used my CNC mill drill to cut the piece fromf 1/4" thick aluminum.





I was going to heat shrink the rim over the aluminum center, but unfortunately I turned the ID on the center to a smooth fit rather than an interference fit.  So, I've tried Loctite 620 to see if that'll hold it.  It held fine during the machining operation so we'll see.

Chuck
So many projects, so little time...

Offline cfellows

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Re: Smaller Horizontal IC Engine - 5/8" Bore
« Reply #40 on: October 25, 2014, 03:33:44 PM »
I'm at a bit of a stop for the moment while I try to figure out the design for the part that attaches to the frame near the crankshaft and holds the pushrod to the cam disk. I like to take my time and come up with something that looks good but still functions properly.

Chuck
So many projects, so little time...

Offline Roger B

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Re: Smaller Horizontal IC Engine - 5/8" Bore
« Reply #41 on: October 25, 2014, 07:16:35 PM »
Coming along well  :ThumbsUp:  :ThumbsUp:

I wonder how those cams were made before CNC. I guess that some of the special chucks and fixtures used by ornamental turners could have been used  :headscratch:
Best regards

Roger

Offline cfellows

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Re: Smaller Horizontal IC Engine - 5/8" Bore
« Reply #42 on: October 25, 2014, 08:50:50 PM »
Roger, I'm sure they used some kind of mechanical fixture or template to mill those grooves.  Would be interesting to see some of those methods...

I settled on a design for the push rod carrier.  Started with a piece of 1/4" thick steel, 3/8" wide and a little over 1" long.  Mostly used the milling machine to shape it...





A single screw will go through a horizontal slot in the push rod and attach to the threaded hole at the top of the mount. 

Chuck
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Offline cfellows

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Re: Smaller Horizontal IC Engine - 5/8" Bore
« Reply #43 on: October 26, 2014, 03:28:31 AM »
Started work on the intake/exhaust assembly this evening.  Guess you could call this part the manifold.  The intake valve cage attaches to the front and the exhaust cage to the back.







I started with a 1/2" x 1/2" piece of square hot roll.  The large hole is 5/16" diameter and will receive the intake valve cage on one side and the exhaust on the other.  The spigot that screws into the head is 1/4" diameter and is threaded 1/4-40 model pipe taper.





Next I'll start on the valve cages.

Chuck
So many projects, so little time...

Offline cfellows

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Re: Smaller Horizontal IC Engine - 5/8" Bore
« Reply #44 on: October 26, 2014, 08:44:45 PM »
I decided the manifold made from 1/2" square bar was a bit too bulky looking so I remade it from 3/8" square bar.  And, I got a decent start on the valve cages.





Still have to drill and tap the mounting holes.  I'll use 1-72 SHCS's to mount the cages to the manifold.  This is a new level of smallness for me so it will be interesting.  The valves will be made from 3/16" drill rod.    Tomorrow I'll see if my local fastener supply store has 1-72 screws.  I'm not hopeful, but they've surprised me before.

Chuck
So many projects, so little time...

 

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