DECOMPRESSION
Moderator: martauto
- WARLOCKM42
- E30 Zone Newbie

- Posts: 47
- Joined: Fri Feb 10, 2006 11:00 pm
- Location: Athens,Greece
- Contact:
Hi guys, i need to lower compression on my M42 engine.I dont want to change my pistons.I need to find a multilayer head gasket or a decompression plate.Which is the best solution?Does any one know were to find this kind of parts?Any ideas are welcome !!!
- flawdaboi407
- E30 Zone Newbie

- Posts: 4
- Joined: Sat Aug 25, 2007 11:00 pm
You will need a thicker gasket. or shave the head and get a thinner gasket for higher comp. dont shave too much or your timing chain will loosen. Im now sure if this will effect the gap between the pistons/valves. I think th older v8's do that to get cheap easy power jsut like P&P.
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HairyScreech
- Engaged to the E30 Zone

- Posts: 6265
- Joined: Sun Jan 21, 2007 11:00 pm
is it posible to have the decomp plate friction welded to the head?
2.8 development thread http://www.e30zone.net/modules.php?name ... c&t=170822
m3.3.1 m20 thread - now running, chip needed - any volunteers?
http://www.e30zone.net/modules.php?name ... =viewtopic&
m3.3.1 m20 thread - now running, chip needed - any volunteers?
http://www.e30zone.net/modules.php?name ... =viewtopic&
- WARLOCKM42
- E30 Zone Newbie

- Posts: 47
- Joined: Fri Feb 10, 2006 11:00 pm
- Location: Athens,Greece
- Contact:
I may order a dec. plate from this guy but i think you only use one head gasket plus a special high temp non setting sealant.Two head gaskets are more likely to blow when you have a turbo on your engine so it gose like engine block+headgasket+dec. plate +sealant+engine head.That way you have two alloy pats bond to each other (alloy plate+alloy head) and the temperature transfer is even between this two parts.It works like an extension to the engine head it reduses compression and enlarges the mixture chamber.Correct me if im wrong... 
