Hello
Although it appeared to be running fine - I decided to do a leak-down test on my 1989 TZR, since I believed the engine had not been rebuilt in its 27 odd years.
After finding the psi was dropping from 6 psi to 3.5 in 6 minutes, I thought it best to bite the bullet and give the engine a refresh before any damage was caused by dodgy seals.
I'm part way through stripping the engine and it turns out that someone has dismantled at least the top end before me. Although, happily the barrels are still on standard bore.
The clues for this were a missing cylinder stud dowel and that the washers for the domed head nuts were not copper.
The thing that surprised me most though was that the head gasket is only one layer thick. I'm assuming a previous owner separated the original layers with a view to reducing the squish(?) - although was there not also a single layer racing gasket available?
Anyway - no damage appears to have been caused to the head or pistons but I'm wondering what (if any difference) I'll notice when (eventually) I get round to rebuilding it with a standard head gasket.
Many thanks!
hey , the standard 2ma head gasket is single layer
Oh! Feel very daft now! I was expecting it to be the same as the gaskets for 350YPVS!
Thanks for the info!
QuoteOh! Feel very daft now!
Dont be...the RD350 tricks was to separate the cylinder head gasket and thereby change the compression -
You could consider to rebuild your cylinderhead to "o" ring type if you look for at change, or... or make one yourself in copper - then you decide the thickness yourselves ;)
sure was need forspeed 350's are multi layer