4G52 HEAD SPACER/THICKER GASKET.

[ADZ]

IS ANY ONE ABLE TO HELP ME WITH ANY INFO ON WERE I CAN GET A SPACER PLATE OR THICKER GASKET TO FIT A 4G52 BLOCK TO LOWER COMPRESSION FOR ORIGINAL TURBO FIT UP WITH 4G54 HEAD OR WOULD THE SERIES 1 4G54 HEAD POSSIBLY LOWER COMPRESSION ENOUGH WITH WHAT LOOKS LIKE FLAT TO PISTONS (THROUGH SPARK PLUG HOLE) IN THE 4G52.?.

[ADZ]

has any one out there had to decompression an astron 1, or has any other info on the matter?
cheers...

[Scorpma82]

no real need to decompress a 2.6L astron I.......they run a compression ratio of 8.2:1 from factory

[ADZ]

cheers scorpma82,
but I'm using a 2L engine this time which i understand are 9.5;1 non turbo and 7.8;1 turbo. but I'm putting my 2.6L head on the 2L and wondering if this will bring the compression down enough for the turbo, I'm thinking yes but curious if any one else has done it and or had to use thicker gasket etc? turbo ran fine on the 2.6L with just knocking back the timing a couple of degrees but that engine/car is out of action for a while.
cheers.

[Scorpma82]

Ahhhhhhh as far as im aware, no it wont lower your compression at all because the 2L runs flat top pistons and the 2.6L runs rather deep dished pistons....but the heads are interchangable (may even be identical in the early version Astrons)

[geezer101]

I'm gonna take a stab at guessing that, due to the fact there are 2 different head gaskets (for the '52 and '54) the 2.6 litre head will have a bigger combustion chamber. Don't know how much lower using the 2.6 litre head will bring the compression ratio down...I really doubt it will be enough to make it suitable for turbo charging though.

[ADZ]

Yeh the 2.6l does run dished pistons, I was hoping the 6-7mm bore diameter difference between the 2L an 2.6L along with the dish in the head might compensate and lower it enough to run the turbo, but will have to compare heads once 2L one is removed. Any one no where I can get a thicker copper gasket or similar from for these engines?
Cheers...

[Sigmaproject]

You cant just throw any old dizzy in it. It will need to be either a Sigma Turbo dizzy, or get your dizzy modified for turbo , by someone like Scortcher.

http://www.performanceignition.com.au/

[SteveG]

Maybe get in contact with RPW. They only list for 4g9*, 4g6*, 4g15, 6g7* and 6a1* but they may be able to help out or point in right direction?

http://www.rpw.com.au/shop/index.php?pa ... 1&Itemid=1

[ADZ]

I see ACL list a range of head gaskets and spacers on there website, no specifics but I'll contact them with what I'm doing an they should be able to help me out with spacer thickness etc.
My 2.6l ran its standard dizzy for a couple of years with the turbo set up on it with no dramas at all?
Cheers for the advice...

[Sigmaproject]

If you use a dizzy that is not setup to retard the timing on boost, then you have to set the base timing wayyyy to retarded at idle and non boost situations.

[ADZ]

No worries, thanks. I retarded mine 2 degrees on the 2.6L when I fitted turbo etc up and she didn't miss a beat the couple of years it was on the road, but I'll keep it in mind for this one.
Cheers...