Mahle Piston Wall Clearance

mallow415 · Post by **mallow415** » Sat Mar 08, 2008 9:00 pm

Looking for some advice on a set of Mahle piston wall clearance. Just started putting together a motor for a circle track motor. 4.060x3.48 chevy with mahle pistons. Had to have a new block remachined for the used mahle pistons. Was checking piston bore clearance and i came up with .0045 piston wall clearance. Does this sound like its on the tight side. Called the machine shop that did the work on the block and he said that is what mahle calls for. I dont have the pistons sheet and couldnt find a spec on mahle web site. What do the people of this great site say?

af2 · Post by **af2** » Sat Mar 08, 2008 9:05 pm

mallow415 wrote:Looking for some advice on a set of Mahle piston wall clearance. Just started putting together a motor for a circle track motor. 4.060x3.48 chevy with mahle pistons. Had to have a new block remachined for the used mahle pistons. Was checking piston bore clearance and i came up with .0045 piston wall clearance. Does this sound like its on the tight side. Called the machine shop that did the work on the block and he said that is what mahle calls for. I dont have the pistons sheet and couldnt find a spec on mahle web site. What do the people of this great site say?

Yes that was the same# as mine new. I am running .0055 because the new bore was where it's at. I woudn't go bigger in my case but have seen a couple do it with no problems after 3 years.

CARRITAS RACING ENGINES · Sat Mar 08, 2008 9:09 pm

What carb are you running.

af2 · Post by **af2** » Sat Mar 08, 2008 9:12 pm

CARRITAS RACING ENGINES wrote:What carb are you running.

CARRITAS RACING ENGINES · Sat Mar 08, 2008 9:27 pm

I asked the ? because we set up our 2bbl motors a little tighter than a 4bbl in the circle track world.

af2 · Post by **af2** » Sat Mar 08, 2008 9:49 pm

CARRITAS RACING ENGINES wrote:I asked the ? because we set up our 2bbl motors a little tighter than a 4bbl in the circle track world.

Why? If you spin 2 engines the same rpm you would need the same clearance I would think.

MadBill · Post by **MadBill** » Sat Mar 08, 2008 10:01 pm

Less power = Less heat = Less expansion?

mallow415 · Post by **mallow415** » Sat Mar 08, 2008 10:15 pm

Were running a 4412 keith dorton series.
I just got off the phone with a guy that builds a few of these motors and he also said that is pretty much right on with the bore specs. So thanks af2 on your response.

CARRITAS RACING ENGINES · Sat Mar 08, 2008 10:19 pm

Because a 600hp 4bbl tour type circle track engine will make more power rpm thus create more heat in the cylinder than a 400hp 2bbl engine. I will also run a tic more clearance in a .060 over bore vs. .030 over bore because of heat.

CARRITAS RACING ENGINES · Sat Mar 08, 2008 10:26 pm

Mallow415 with a 4412 you will be fine.

mallow415 · Post by **mallow415** » Sat Mar 08, 2008 11:23 pm

Thanks Guys! That will work for me!

CNC BLOCKS · Post by **CNC BLOCKS** » Sun Mar 09, 2008 8:47 am

On the Mauhle pistons the clearance is built into the skirt and if your block was plate honed 4.060 it should be fine.
And if your using a 010 block and going .060 over I hope your machinst took the time to sonic test the block as we don't find to many blocks that are safe at .060 over.

Good luck with your build Carl

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Mahle Piston Wall Clearance

Mahle Piston Wall Clearance

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