Author Topic: Piston Projection Question (Read 3060 times)

myke_w · « **on:** July 02, 2007, 08:36:28 am »

It is safe to assume a block will have the same piston projection with old or new pistons, correct?

In other words, isn't the only thing that can affect it is a block deck job.

myke_w

Black Smokin' Diesel · « **Reply #1 on:** July 02, 2007, 09:07:08 am »

Quote from: "myke_w"

In other words, isn't the only thing that can affect it is a block deck job.

There's more to it than that, I think crank and rod bearings have something to do with this. Since you're only replacing the pistons, you should be ok I think.

myke_w · « **Reply #2 on:** July 02, 2007, 11:16:22 am »

I'm replacing pistons, main bearings, rod bearings etc. but nothing will be oversize, in other words it's just going back together with stock stuff (same as what came out)

bigblockchev · « **Reply #3 on:** July 02, 2007, 07:11:50 pm »

While crankshaft center to block deck is one factor in the piston height, it is certainly not the only one. The stackup of tolerances from piston pin height, connecting rod center to center distance and even actual crankshaft stroke, can affect the piston height. None of these are perfect so short answer is measure it , it is easy and may save you some grief. Cheers Dan

subsonic · « **Reply #4 on:** July 02, 2007, 08:48:06 pm »

I remember reading that andy2 had to line bore his block after checking projection. He had uneven projection. One side higher than the other.

Mark(The Miser)UK · « **Reply #5 on:** July 03, 2007, 03:34:32 am »

What part of the crank-rod piston setup creates the most variation? If its what I'd regard as the the hardest item to set up (I could be wrong) ie the crank; then at my estimate some of us have 1620cc engines :shock:

myke_w · « **Reply #6 on:** July 03, 2007, 07:35:57 am »

I guess I'll just buy 2 gaskets and send the one back I don't use

I just figured the projection was a function of deck height only, considering everything else would have to be built to tight tolerences.

Good to know there's more involved

thanks guys