S2 smokes (a lot) on start up (again)

Post by: **ftsoft** » Tue Oct 17, 2017 12:54 pm

Carlos

Yikes! That sounds a lot like my experience as it has gotten worse.

Frank

Post by: **ftsoft** » Tue Oct 17, 2017 2:55 pm

Types26/36

I like this solution of fitting a seal. I talked to my mechanic about it and he agrees it looks like a nice mod. We are still trying to sort out the valve guide saga as they had sent the head out, so trying to resurrect what the machine shop did.

Frank

Post by: **Craven** » Tue Oct 17, 2017 4:13 pm

Remember an oil film between the guide and valve stem is a critical factor in valve cooling.
Using a quality bronze like a Colsibro guide that has a temperature coefficient close to aluminium the guide to stem clearance can be reduced to near zero. The wear characteristic is so low that if correctly fitted and then honed too size against the actual valve stem diameter will outlast the rest of the engine. Once done oil usage via the valve guide will be reduced to a rate well within the design parameters.