Composite head gaskets change to tin gaskets

[pitsnow]

I am thinking of a cheap way to pick-up some extra torque.

Would it be worth to change the composite head gaskets to tin gaskets to gain more compression?
My engine does not do more than 5000 miles a year and usually gets pulled apart every 2 years anyway.
The current 28cc heads came with a 9.5:1 tag from V8development.
The cam lift should be OK with the thinner gaskets but would obviously be checked.

What do you think?

[jwriyadh]

If you can manage the detonation, then fine.

I may have screwed the maths up but;

assuming a 4.6 motor and the gasket volume difference is 8cc then I make your new CR 11.3:1

jw

[pitsnow]

Hm, I thought the increase was something like 0.7 to 1 in compression ration.
http://www.rpiv8.com/engine-4.htm#gaskets
That would have made it 10.5:1 at the most which would be fine with Ron 98 super unleaded.

After your post I had a better look at it.
1 cylinder 4.6 with 9.35 compression ratio must have a deck cc of just over 33cc (61cc minus 28cc of the head) to end up with 9.35:1
569.5 cc / 61 cc = 9.33

If you remove 8 cc due to the tin gasket instead of the composite gasket, you should get 569.5cc / 53cc = 10.74

That is getting high I agree. Especially since my heads came with a comp ration given as 9.5 : 1.

Is there a gasket size (aftermarket) between tin a composite?

[ihatesissycars]

V8 developments have a comp gasket that is halfway between a tin and normal comp gasket thickness i believe although i could be wrong so it'd worth checking with them.

10.5:1 should be ok with 95 shouldn't it? Many maodern engines run a higher comp ratio than that and will run on anything. Bike engine too, 13:1 comp ratio and 95 ron fuel. You're running a fairly rumpity rump cam aren't you? A 404? That has the effect of lowering the comp ratio on a running engine as opposed to static compression. I'd say go for it. Its only time and a few cheap gaskets. Plus it'll give you something to do in the winter months along with your timing cover change etc.

[Wotland]

Hi,
Head gasket set are aviaible in different thickness ( 0.018, 0.040, and 0.050) from DD in USA.

http://www.aluminumv8.com/catalogpages/ ... onents.htm

Cheers

[katanaman]

If you go for there give the inlet to head a good check as odds on they wont be in line anymore so you will have to either skim the inlet on the head or the inlet itself. I think the compression ratio will be fine with a big cam in it.

[pitsnow]

If you go for there give the inlet to head a good check as odds on they wont be in line anymore so you will have to either skim the inlet on the head or the inlet itself. I think the compression ratio will be fine with a big cam in it.

No worries there, the IDF down drought manifolds are split per bank.

My cam is a “stealth” from V8Dev. Duration is a little shorter than the H404 but lift is as much I think.

Thanks for the link Dimitri