Ever heard of this????

[t-dub13]

Reading a story on Vintage sleds . com, I ran into a mention of someone raising compression in a motor by cutting a head gasket out of aluminum foil. Haaha! Sounds like a great idea as long as it seals, doesn't blow (melt) and the piston doesn't crash the head. You guys think this is just a vintage racing myth, or a great poor man's hop-up?

[kidsperformance]

The Kaw motors have a very thick head gasket....plus the head is a total "hemi head"....If my memory serves me correctly I think the squish clearance was .110 So if the remove the head gasket, there still is a recessed cut into the head plus I think the edge of the piston still lacks about.020 that the piston stays in the cyl.....

[kidsperformance]

what the heck am I posting I reread your post and realized I don't even think you were takling about a kitty cats.....duh....even so "back in the day" as I remember as a kid some stuff back then was very crude. I know taking some vintage motors now and adjusting them to modern day standards a lil turns the motors to produce more power I'm hearing now......esp with pipes

[1121racinkitty]

BILL ROCKS!!!!!

[t-dub13]

Yeah, but, I'm definitely going to look into it next time I pull a the little motor apart. I'm hoping that Suzuki's motors are all similar. I've built a sick JR motor,and if it's the same then I think I can definitely do the "aluminum foil poor-man's-compression-ratio-bump.!!!! It sounds too good (easy) to be true!!!

[Engineer]

Aluminum foil will work and copper foil works too. I have used the permatex copper seal without any type of gasket on small engines to "boost" the compression. Usually on a briggs when street racing mini-bikes or go carts as a kid. The thing is that it won't last very long. You'll need to redo it every 3-5 hours of run time and more if you are racing.

[t-dub13]

Interesting. I wonder why it doesn't last. I wonder that alloy the Aluminum foil is compared to an OEM aluminum head gasket. I can't imagine it has a temper, maybe it's too soft?

[Engineer]

I think it has something to due with thermal expansion and contractions wearing out the seal or the combustion oxidizing/burning the material. Just a guess though.

[t-dub13]

Makes sense, iron cylinder and an aluminum head. Must need some thickness between them for the difference in thermal expansion. There's a lot more thermal mass in the cylinder to heat up too so the head grows a lot sooner and more.