Headgasket Help

[Stevin]

I need some help, I need to know what the standard headgasket compresses 2 ? cause I want to cut my pistons a little higher, so that they sit the same height as the gasket, and not the top of the block.

Thanks
Steve

[kam-325i]

Why?

[Ant]

Very bad idea !!!

if you want to raise the CR there are much better methods without resorting to almost complete remopval of the squish band between the piston crowns and head.

I assume you are creating a hybrid bottom end?

Cant offer more advice without all the relevant info dude

[Stevin]

Yeah, I've got another set of S50B30 pistons that I'm using on a 324td crank, 325i rods.

The pistons need to be cut down... cause they come out the block.

I've chnaged from a 328i Crank, on M40B18 rods, and M3 pistons, to this setup.

which takes it from the 2.9, to a 2.8 , I want to run more Compression. but cause the rods I'm using r slightly shorter than the ones I used b4, there is still going to be a small dish on the piston, and a loss of compression...

So I want to cut the piston taller... I have done this B4 on many other engines, I just need to know how much the Headgasket compresses... if I'm not mistaken the standard pistons also come up out of the bore... I just have 2 cut these pistons in 2 mm around the edges, cause the gasket is only 84mm... but it works I know, I've done that B4 with my old setup.

Oh just to clarify my original post, I'm not going to have the piston sitting the same heaight as the gasket... cause then I'm gonna hve some valve clearance issues (which can be solved by pocketing the pistons... but I don't want to do that after cutting them down) I want them to go higher than the block, thats why if I knew how much the gasket compresses, I know how much clearance I have to work with

[Stevin]

So ? No info... think BMW will be able 2 tell me about this ?

[Ant]

could always measure the old gasket M8 ??

[Demlotcrew]

Or you could measure from the centre of the wrist pin to the top of the piston on a stock 2.5 piston?

Andrew

[Stevin]

I would have measured the old one, just I already chucked it... not bright on my part.

Just confused why should I measure the wrist pin, on the old pistons ? I think I know why u say but, I'm not sure if I want it the same height as the 325i pistons