Best Valve guide material..SI...others?
 

My machinist recommends SI valve guides (see SI Web Site ) for my 993. I know Steve W. has his own (or are they?) and others seem to have other formulations etc.

I know I won't get an answer but what is the best guide for street/some track use / (yes, I know to throw out the OEM guides). Its very confusing with lots of "trust me" type statements without any quantitative information (its the engineer in me I guess...)

Cheers,

Mike

The old reliable standby material is phosphor bronze which SI does carry.

There are some newer alloys that are touted by various shops.

I went w/ the phosphor bronze when I did my 993 motor

I had heard about some sort of Aluminum-bronze alloy...sounded pretty hokey to me.

The phosphor bronze were developed for the 935s and have been successfully used on every model since.

When the newer alloys have as long and good a record they will deserve the same consideration. But I didn't want to experiment