about 5mm TRD headgasket

[filh]

As I'm rebuilding my old engine , i spoke about 5mm Trd headgasket to the machinist. he told me that with that gasket , pistons had to be worked on to avoid contact with valves .not at idle , but at high revs !

any experience about that?

And if so , there won't be much gain , as you get more space in combustion chamber by remachining the valves spaces on pistons?

Filh

[jamiemirror]

Smallport engine ?
I'm interested in that too. Maybe your machinist can try clay test with dry build ? AFAIK there must be at least 1mm distance between piston and valve surfaces, preferably 1.5mm.

[Denmark]

You can run serius boost with a headgasket like that



I know you mean 0,5mm


/Skassa

[apardal]

I have 0,5 mm head gasket and I shaved 0,5 mm to the head. No contact. I've heard people shaving 1,35mm to the head and still no contact.

Tell your machinist that no matter what happens to the drive belt, at stock setting the valves never hit the pistons. That gives you an idea of how big the space has to be.

With 0,5mm gasket and 0,5mm head shave, the valves still never hit the pistons.

Best regards

[meshin]

apardal Wrote:I have 0,5 mm head gasket and I shaved 0,5 mm to the head. No contact.

How much is compresion ratio with 1 mm shaved ??

[filh]

Thanks , i'm a bit more confident now .
Maybe more critical with a high lift valve camshaft ?
to Jamiemirror :my engine is a bigport model .
Yes Denmark, sorry I meant 0,5mm . for sure with 5mm headgasket , no need to worry
filh

[ZDoman]

Are you speaking about the bigport or the smallport engine?

I have a smallport engine and I shaved -0,7mm with OEM head gasket, but now I'm thinking of trying a 0,5 or 0,8mm TRD one. Anyone has experience about this?

On the club4ag.com I read that -0,1mm of the headgasket will raise the comp.ratio by 0,1:1

[Hoey]

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?

[Hoey]

^^^ Can anyone answer this one? I am going to be purchasing a metal-headgasket when I turbo my corolla. Id like to keep my stock compressionbor even lower it slightly so I can run higher boost. stock preferably.

[apardal]

Hoey, you'll need a thicker head gasket for a forced induction setup. 1,5mm I think.

Best regards