A friend and I recently built a cb175 vintage GP racer, and one of the things we talked about, and subsequently did was use thin copper head gaskets to achieve maximum swish with the high compression pistons and tubbed combustion chambers.
Obviously this is not a 2 stroke bike, however I have heard several times of folks decking the heads on their bikes to bump compression a bit (or a lot)
Anyone achieve this result by using thin ('er than stock) copper guys? Seems like it would work to me, as I know the Kaw's came stock with copper head gaskets, figure a good anneal and torque would keep the seal and one could measure deck height without machine work, and really dial it in.
Anyone running them in their GT's?
Copper head gaskets anyone?
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JFISHSOLEVIBE
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tz375
- Moto GP
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Re: Copper head gaskets anyone?
I just pulled a 750 GT motor apart that has a copper gasket and that was blowing badly. They are harder to seal than a composite gasket On Cb160/175 motors I have to machine teh block and pistons and head anyway, so a composite gasket works well enough there on our race motors.
On an RD they seem to work fine and on my years with Triumph twins I had no issues with copper gaskets apart from thr occasional leak
The huge advantage to me of copper gaskets is the fact that they do not stick like crap to a blanket and are reusable. My race GT750 has a Cometic composite gasket and no leaks at very high cylinder pressures.
Cometic and others can supply copper gaskets. In fact I have two copper gaskets here now that I may try in the next race motor to try to prevent leaks. I'll use a steel backup ring though in a groove.
On an RD they seem to work fine and on my years with Triumph twins I had no issues with copper gaskets apart from thr occasional leak
The huge advantage to me of copper gaskets is the fact that they do not stick like crap to a blanket and are reusable. My race GT750 has a Cometic composite gasket and no leaks at very high cylinder pressures.
Cometic and others can supply copper gaskets. In fact I have two copper gaskets here now that I may try in the next race motor to try to prevent leaks. I'll use a steel backup ring though in a groove.
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Coyote
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Re: Copper head gaskets anyone?
A board member here had 6 of those thin copper gaskets made up for the GT750 and offered them to the folks here. I bought one but sold the bike before installing it. I re-sold it. I can't really speak on any performance gains or loss as I never used it. I do have a picture if it though. I'll post it if I find it. Uh yeah. Here it is.
I was born with nothing and still have most of it left.
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1978 GS1000C
1976 GT550 ongoing money pit.
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1978 GS1000C
1976 GT550 ongoing money pit.
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Suzukidave
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Re: Copper head gaskets anyone?
Years ago i thought i would help the group and have a whole sheet of copper gaskets made up , turned out to be 30 something gaskets . I tried to sell them for cost and couldnt give them away .. live n learn 
the older i get the faster i was
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JFISHSOLEVIBE
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- Suzuki 2-Strokes: 1972 GT380, 1972 and 1969 Honda CB175
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Re: Copper head gaskets anyone?
All great input guys. Think I'll forego the copper for now.
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tz375
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Re: Copper head gaskets anyone?
Or just buy a few from Dave.
The two issues on a GT750 are bore placement which can be off center on some motors and with high HP and/or high compression motors, they tend to leak.
Copper gaskets are a better way to match the head and barrel than composite gaskets and unless you are planning more than say 120 HP, use Coppaslip to seal them.
The two issues on a GT750 are bore placement which can be off center on some motors and with high HP and/or high compression motors, they tend to leak.
Copper gaskets are a better way to match the head and barrel than composite gaskets and unless you are planning more than say 120 HP, use Coppaslip to seal them.
