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Pony cam shim

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16 years 8 months ago #10818 by STEPHEN
Pony cam shim was created by STEPHEN
I was building up my 212 pony engine and noticed I had loads of excess cam end play. What I did is cut brass shims from .010 stock on a waterjet and placed one on the cam bearing between the gear and the block. I think it will work ok. I have 2 extra shims if any are needed.
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16 years 8 months ago #10864 by Jack
Replied by Jack on topic Pony cam shim
You got to be careful puting shims between moving and stationary parts. There's not much metal there. If they rub much at all they can heat up fast and then break up and pile up.

If you need to limit end play with shims, it's usually better to machine down one part or another, then machine a washer at least 0.060" thick to make the required clearance.

This is just general machining. As to cam end float on a pony motor, I have no idea what's acceptable. And are you sure you want to shim the cam outward? This modifies the lobe/tappet contact pattern. And what are you shimming to on the other end of the cam float? What are the chances that you will tear down after a dozen hours or so to see if you are doing damage to the shim or eventually to the engine?

I tend to be pretty careful with such modifications when I have to put them in and forget them.

Jack

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16 years 8 months ago #10907 by BillWalter
Replied by BillWalter on topic Pony cam shim
Stephen; The end play has always been there. Don't worry about it. Won't hurt a thing

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16 years 8 months ago #10908 by STEPHEN
Well, this block has some serious mods to the main bearings already due to a past owners thrown rod. Damage was to the oil well/retaining dowel area and the usual bore skirt notch & cracked base under the crank. The crank has been turned down to around 1.75". I dismantled 3 ponys & all had the notched skirt from broke rods. Good point about the shim thickness, A better way would have been to make a thicker retaining tab for the bolt holding the gear to the cam. There still is clearance on the high end, and the gear set has a constant stream of oil from below. Gears are spur with minimal end thrust if any. All told, I'll be waiting to see what lets go first. I have a few good cranks, rods, pistons etc & have a good lead on a used block.

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