about 5mm TRD headgasket

[jamiemirror]

Hoey Wrote:what is the stock thickness on the small and bigport engines?

Why whouldnt everyone just get a TRD or other metal headgasket the same size? wouldnt that be perfect?

1.2mm uncompressed/1mm estimated compressed.
Check 7AFE gasket too (heard that they are 0.7mm).

[Hoey]

so a 1.5 mm Metal HG will be ok? so then instead of 9.5:1 id be approximately 9:1 comp with a 1.5mm?

With that thickness will i be OK for blowing a HG?

[jamiemirror]

Hoey, stolen thread warning
You can run up to 0.6bar boost even with stock 9.4 CR on premium fuel.

[Rasteirinho]

This is an old thread but i need to know waht's the thickness of the standard head gasket?

I need that to make the calculations about how much i must skim my engine's head to achieve the desired compression ratio.

I was thinking to increase until the 11:1? What do you think? Is it too much?

[Apolan]

im interested in this topic too.. from what i've read, the bigport engine has 7.56 mm lift and 1.2 mm headgasket.

what i want to know is how much does the cam timing change if you say use 0.5 mm headgasket and shave additional 0.5 mm from the head (making total of -1.2mm). Would you need adjustable cam sprockets in this case to make a positive torque gain and would this -1.2 mm drop make valves interfere with pistons?

and what sort of CR do the(MAP) bigport engines have 9.4 or 10.2 ??!

[Rasteirinho]

I've measured now a new OEM gasket and it has 1,4 mm however when fitted the thickness will decrease obviously.

I think the std CR for the MAP bigport engine is 10:1 and i don't think that is necessary to fit adjustable sprockets if you reduce 1 mm.

[gon]

the MAP ae86 bluetop EUR engine has 10:1 .
The standard head gasket compressed has 1.0mm
if you want 11:1 you should shave 0,5mm your head and use a 0,5mm trd head gasket....
I have a JDM AE92 engine (9.4:1) and the head has been shaved 1.2mm and i'm using a 0,5mm trd head gasket.
I think I have something close to 11:1 now ....
Using 8.5mm cams th engine is now intrusive, it means that if the engine belt fails there will be a problem, but only if that happens... ( lots of engines have that problem in standard form)

[Apolan]

great info! but will there be any interferance if shaving total 1.2 mm and using stock cams (7.56 lift)?

[gon]

i'm not sure , but i think yes ......
try it yourselft

[apardal]

I would guess you might get away with that kind of shaving + metal head gasket.

A nice bottom end power would be defenately gained. But the raise in compression might wear those conrod bearings a little bit more.

Best regards