How much cc is a normal head gasket?

[Guest Anonymous]

As seen below, I have an 1,8i head, 63cc chamber volume.

In theory this should give me a (497,5 + 63)/63 = 8,8:1 cr. (I

have flat-top pistons). But is the volume of the head gasket

relevant? And how much is that?

Thanks,

Hugo

[Guest Anonymous]

If I estimate gasket thickness at 1.5mm and the bore is 89mm,

the volume in the gasket is 9,33cc. Giving 72,33cc chamber

volume and 7,8:1 CR, which would be great fo mu turbo

plans. Do these calculations and estimate make sense?

Hugo

[Guest Anonymous]

you need to measure the thickness of an old one

[Guest Anonymous]

(nt)

[Guest Anonymous]

"" If I estimate gasket thickness at 1.5mm and the bore is 89mm, the volume in the gasket is 9,33cc ""

That's probably close, I did not actually check your math, but I get about 9.21 cc from a 90 mm bore with the gasket at 0.057" installed.

At 90 mm bore, each 0.5 mm height equals 3.18 cc.

The #279 gasket is a nominal 1.5 mm, and the #280 gasket is 0.3 mm thicker. I only use the thinner one.

The 1.5 mm gasket has an installed thickness of 0.057", and this does not change whether clamped with stock head bolts or the much higher clamp load of ARP's head stud kit (finer thread pitch + higher tightening torque).

WTF are you doing with a 3 mm gasket ??

[Guest Anonymous]

'cuz I wanted to confirm the effects of the stud kit from ARP on the gasket thickness.

[Guest Anonymous]

You say your 1,5mm gasket has a compressed thickness of

0,057", which is 1,4478mm. Using that figure and the rest of

my stock figures I get 9,00696etc cc gasket volume, which

gives 72cc chamber volume and therefor 7,9:1 CR. Still good

for my turbo set-up, I think. BTW, I haven't got a clue what the

3mm. thick gasket is. It does fit the M10. Cann't remember

where it came from.

Hugo

[Guest Anonymous]

(nt)

[Guest Anonymous]

"" You say your 1,5mm gasket has a compressed thickness of 0,057", which is 1,4478mm. Using that figure and the rest of my stock figures I get 9,00696etc cc gasket volume, which gives 72cc chamber volume and therefor 7,9:1 CR ""

Hugo,

You are getting close, but using math is a bit of a compromise, even with flat-top pistons !

You still need to add the volume along the sides of the piston above the first ring.

The piston is not the same diameter over its height (nor is it round).

The diameter above the top ring groove is much smaller.

On a Mahle flat top, this is about 0.356 mm less than the nominal piston diameter, and is about 7.4 mm in height.

This means you need to add about 3.67 cc to your volume.

Another consideration is the where the piston top is in relation to the block deck. Is yours flush or (more usual) slightly lower than the deck? Typically, this is a smaller volume than the area discussed above.

The best way to confirm volumes is to use an accurate burrette and liquid. You can check the chambers easily, and you can use grease to seal the top ring and measure the volumes in the cylinder above the top ring. It is the best way to get the volume of a dome or dish, which are usually too complex for math.

[Guest Anonymous]

(nt)

[Guest Anonymous]

Volume in cc = 3.1415 x radius (in cm) x radius (in cm) x thickness (in cm).