Quote:
Originally Posted by hcoles
people on this forum know this...I would guess.... why is it such a secret? I'm like you... I am curioius and just want to know... if they all come from some guy in China working in his backyard... that's fine could very well be outstanding quality/etc.... as you say we just want to know.. sometimes I hate being an engineer... we sometimes have intense curiosity burning a lot cycles for not much gain.
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For my part, its no "secret",...
Everyone has an opinion based on personal experiences so one simply decides who one wishes to believe. We've used a phosphorus-bronze material thats made to our specifications in all our heads since 1979 with excellent results. They do not exhibit wear problems and do an excellent job of retaining oil to lubricate the valve stems. I must also mention that fitment and guide-wall finish are VERY critical to proper component life. This means that the guides must be properly installed in the heads and the bores should be honed (never reamed) to fit.
We don't do any other types of engines here so it really comes down to what you have most luck with and the P-B material has been very good. Like everything, its always a compromise to balance guide wear with valve stem wear but the newest valves have hard chrome stems and last a long time. I'm happy to say that we've redone very few guides since we began using this material and thats several thousand heads,....
JMHO, of course.