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

[Mike Juzenas]

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

[Bill Verburg]

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

[Mike Juzenas]

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

[Bill Verburg]

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