Hello,
I'm rebuilding a C15 SS80 1964. I've measured the thickness of my cylinder head gasket (~.039 - .040") and bolted the head onto the barrell without the gasket and measure the thickness of the gap which is about ~.035 - 0.38 depending on which corner you stick the feeler guages in. Hence, compression on the gasket could be as low as .001" in one section. I think the head has probably had one too many skims, and I am worried that the gasket will blow (or leak oil).
I guess a slightly thicker gasket would be good, does anyone know where I can get one off these or if there is another trick commonly used. Or even if 001" gasket compression is ok.
Thanks
Steve
Steve,
I have a spare solid copper gasket that came off of a C15, your quite welcome to it for the price of the p+p, the other trick with these is to put a thicker gasket under the barrel, or double up.
TTJohn
Hi TTJohn
Sounds like an excellent offer, thank you. How do we arrange that then!?
Steve, you can e-mail me with your address to Jomichael@aol.com
Regards TTJohn
Steve.
It does sound as though you head has been skimmed too far - I think 1 thou of gasket compression is going to be too low and I'm sure would cause problems. I think 5 thou would be the minimum required. My old C15 gasket is about 38 thou and a new one might be a little thicker but still not thick enough.
The simplest solution might be to get 4 thou skimmed off the top of cylinder liner - this will increase the compression ratio by a small amount but shouldn't be too significant. The alternate solution would be to get a bespoke copper head gasket made of the correct thickness, if possible - there are a lot of companies that advertise this service.
Just found this 47 thou thick C15 gasket advertised, albeit in the US. If the standard one is normally 40 thou thick, one like this might solve your problem.
http://www.bsaunitsingles.com/item.wws?cpubcode=BSAU&sku=40-0140
I had the very same problem with my bike, getting a good head gasket and getting a seal. ( b40 ss 90 ). A good gasket is avaleble on ebay by PES, I think there called. I ended up cutting a gasket out of some high tempreture paper gasket material, used on steam engines ( 1mm thick ) and putting it under the pes gasket. Works great, and i ride hard and fast and i have not blowen it yet.
Iv just measured the spare gasket material i have and it is 0.4mm. My mistake.
I had weeping on my ss80 head gasket.
Only cured it by cutting out a jointing paper gasket and wellseal.
Fixed