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Suzumushi
02-09-12, 19:56
hi,
anyone knows what is a standard head gasket thickness?

regards

WS

arrghh... Steve can You please move this thread to proper forum section? my bad...
wrinx
02-09-12, 20:23
Moved to Q4 Tech ;)

wrinx
mpampis_
02-09-12, 20:30
Standard head gasket is 1.9 mm
bussone
04-09-12, 12:20
Standard head gasket is 1.9 mm


I confirm mpampis's input, its 1.9mm.
Steve Webb
04-09-12, 22:53
So how much difference does fitting a 1.6mm head gasket make? It the extra compression noticeable?
MaxiBoost
05-09-12, 04:50
So how much difference does fitting a 1.6mm head gasket make? It the extra compression noticeable?

Im trying to calculate
many engine compression ratio calc on internet

1.9 mm to 1.6mm
8:0 cr to 8.17 cr
mpampis_
05-09-12, 04:58
As Hakan (maxiboost) say above 1.17. Not only in theory but in practice too. I have 1.6 head gasket and I measure CR after rebuild
MaxiBoost
05-09-12, 08:49
As Hakan (maxiboost) say above 1.17. Not only in theory but in practice too. I have 1.6 head gasket and I measure CR after rebuild

mpampis, you need measure "before" engine rebuild
like this:
http://www.automedia.com/Checking_Compression_Ratio/pht20020701cr/1


you can cylinder compression test, after the rebuild engine
its not compression ratio, its cylinder pressure test
mpampis_
05-09-12, 09:23
We measure it with petrol for a compression ratio, not compression in cylinders. I have 12 bar compression
MaxiBoost
05-09-12, 12:40
We measure it with petrol for a compression ratio, not compression in cylinders. I have 12 bar compression

mpampis could you explain more please ?
mpampis_
05-09-12, 12:54
Without camshaft we put gas to the first cylinder from the spark plug hole when piston 1 is on the top dead point. After we put gas in the 2 cylinder when the piston is on the down dead point and with that way we put the compression ratio at 8.2:1
hf hpe
05-09-12, 19:24
mpampis_, are you sure for 1.9
because all after market gaskets are 1.78 before fitting
mpampis_
05-09-12, 20:13
I'm sure 100%. On the other hand I didnt see anywhere 1.78
hf hpe
05-09-12, 20:23
http://hfhpe.clubalfaromeo.com/berlinasportivo/elring_gasket.png
mpampis_
05-09-12, 21:13
You make me change my opinion I had all these years.... Who knows then. Maybe you are right. For me Everyone who asked for a head gasket they sell as oem part 1,9 mm
MaxiBoost
06-09-12, 05:09
Without camshaft we put gas to the first cylinder from the spark plug hole when piston 1 is on the top dead point. After we put gas in the 2 cylinder when the piston is on the down dead point and with that way we put the compression ratio at 8.2:1

wow its a fantastic method
but any gasoline leak from piston rings ?
mpampis_
06-09-12, 11:55
No, specially when the pistons and rings are new and as they have to be
Varypodaros
08-09-12, 21:30
HP hfe the gasket in the picture seems to have 85mm diameter. Are you sure that the characteristics are for OEM engine? It should have 84 mm diameter.
hf hpe
09-09-12, 14:09
yes the oem gasket is with 85mm rings, the bore is 84mm
most racing gaskets are 85mm too
spesso have 86mm to
Evodelta
10-09-12, 13:31
It's 1.9mm.
Putting a thinner HG on without any other mods will increase the risk of the piston hitting the head, it's only 1mm away as standard.
corriedw
21-09-12, 18:06
Have anybody measured an old gasket that was removed from an engine? Because composite gaskets compress about 20 - 25%. On the Alfa TS a new composite gasket is about 2 mm and it compresses to 1.6 mm.

A thinner gasket will make the risk of detonation higher on an hard working engine, but I can't say by how much.

I don't believe the piston will touch the valve yet, unless when the head was resurfaced and lot of material was removed.

When the piston hollow and combustion chamber are measured the volume of the gasket space must be added. Both methods of measuring is good, but we found it more accurate before assembly.
hf hpe
24-09-12, 07:36
when I measure my was 1.6
but don't know is the engine overhauled