decomprestion plates --(dustin)

old forum · hod rodder Joined: 04 Oct 2001 Posts: 15499

were can u get copper head gaskets for geminis ??
as i am planing to super charge my 1600 which has had at least 40 thou of the head
i would like do decompress the engine for the supercharger

what bits and pices do i need ???
is a blowof vaulve needed in a suck through ???
as far as i know it isnt ???
i have modified he stock manifold to take 3 inch pipeing that will run to the supercharger
the blower is mouned on the old emition pump brackets
with slight mods

what can i do for cooling
as i cant use a intercooler in a suck through setup
i am using a 350 holley for a start
may get a small 4 barrel
or a weber

old forum · hod rodder Joined: 04 Oct 2001 Posts: 15499

Yes copper gaskets/decompression plates are available for the gemini, ridgecrest engineering(sydney??) have them IIRC.

You can NOT run a blow off valve with a suck through setup, because it would vent air and FUEL into your engine bay, not a pretty thought...

I would suggest rather than running a decompression plate, hunt yourself a new head ($30 or so, it is a gemini afterall) have it ported and rebuilt, then fit dished top pistons, if this doesn't deliver the required drop in compression then you can open up the combustion chamber a little, just don't go overboard.

old forum · hod rodder Joined: 04 Oct 2001 Posts: 15499

Ive just finished doing a supercharged sohc gemini for a customer. Went with a radical idea and used a 2litre head on a 1600. Mounted the blower on top of the stock manifold, with a 350 holley. carby is thru the bonnet but hell it looks cool. Blower is of a 2litre toyota six cylinder. Running 45% overdriven giving 14psi boost on standard 1600 bottom end, a static compression of 7.0:1, vehicle runs 13.6 @ 103mph. Have fun