PROFILE GASKET +DECOMPRESSION PLATE

Mon Sep 10, 2007 5:12 pm

Hi guys i have one more for you so here we go...I will use a decompression plate on my M42 engine it will be 3mm thick. Will i have problems with the profile gasket???All engine is rebuild using new components.The engine head will stand 3mm higher so is there a possibility that profile gasket may leak???Thanks in advance!!!

Mon Sep 10, 2007 6:08 pm

3mm is too mauch for the profile gasket to take up reliably, when new its possibly ok but as it shricnks with heat and age it'll be borderline as you suspect.

If you are doing a full rebuild , why not machine the piston crowns the 3mm you're wanting to achieve the same goal ? they are 16mm thick in places(average) so a little haircut will be OK - check before cutting mind- BMW do like to change specifications on the M42 engines- weekly it seem :lol:

HTH

Mon Sep 10, 2007 9:52 pm

I need to lower compression in order to turbo boost the engine.If i do this little haircut, the pistons are more likely to brake i can allways change pistons with forged ones and get the compression i need but i cant afford this right now....therefore i have chosen the decompression plate.I was thinking if i add a 3mm plate on the flat side of the gasket and some non setting high temp sealant if it will last long, new gasket is 7mm thick .I know a lot of people used dec.plates on M42 engine and i was wondering if any one had problems. Someone told me to use neoprene under the gasket to make it stronger and other things like that.... im trying to find a more "professional "something that really solves the problem and everyone can afford.Any way thanks for your reply Ant you're a zone god, if i find a solution ill post pics and details...in the meanwhile all ideas are wellcome...

Tue Sep 11, 2007 6:06 pm

I talked to Mike from ferriday this guy is a pro... He told me that two plates are included in the decompression plate kit to solve the profile gasket problem and even send me a pic of them to print on paper cut them and make sure they fit.They are made at the exact shape and dimension as the ruber profile gaskets.Their thickness depends on the thickness of the decompression plate you order of course.He also told me that he has sold enough of them and no one complained about a profile gasket failure.So there you have it a cheap solution to decrease compression on a M42 engine whithout having to worry about the profile gasket is ferridays decompression plate!!!

Tue Sep 11, 2007 6:12 pm

That's a link to your Yahoo inbox, not the image

Tue Sep 11, 2007 6:17 pm

Want my yahoo code or can you please tell me how to show the image in here??

Tue Sep 11, 2007 6:25 pm

Can you save the image to your pc? You can then upload it to one of the free hosting services such as imageshack.us?

Or just forward the email to me & I'll host the pic

Tue Sep 11, 2007 6:30 pm

here you go thanks for your help

Tue Sep 11, 2007 7:34 pm

That'll work dude !

Mike is the don @ Ferriday, still keen to try the thermal intake gaskets on my next project.

make sure and get some Curil-T of Mike when you order the decomp plate dude !

I'd use some 5mm longer bolts too, for good measure

on M20 with decomp late of 3mm there's only 8mm of thread engaged fully, I use 160mm bolts to give more than the OE Bolts.

Belt and Braces.... you betcha

Tue Sep 11, 2007 7:49 pm

Curil-t is the sealing non setting compound i suposse??? as for the longer bolts i will have to order them since i dont think im gonna find them here in Greece...any ideas??? Any way i think in m42 the bolts are long enough. can any one confirm this???