Saw a 355 that had valve guides updated to silicon bronze- any good?

Check out the "valve guide" write up on this site. You will have to scroll down a bit :

http://www.performancecylinderheads.com/ferraripage.htm

 

Silicon Bronze has been "the" choice in p-cars since as far as I can remember. Though they do cost more.

The iron guides are very "old" technology.... That is the material used on my 50+ year old triumph motorcycles.

Steel is the "cost effective" fix Which is a reason ferrari went that route.

 

Sintered iron guides like the material now provided by Ferrari is probably the best material offered by a small margin but the only guides made in that material are from Ferrari at a cost in excess of $50 each. Using my basic math skills for 40 guides that amounts to a pile of money. Then you have to consider that those are not all that well made and using them will mean compromises in the quality of the valve job. For a small fraction of the price of OE guides you can get top quality silicon/manganese/bronze. It is an outstanding material for the job.

Valve guides are like hamburgers, you get what you pay for. Not all bronze guides are created equal.

 

OK, I'm almost afraid to ask, but what was used for the 348 valve guides, and were they ever a systemic problem in that model for any particular reason?

 

speaking in terms of domestic heads I've done over the years, for example a 350 Chev, my guide of choice is the K-Liner which is a Phsosporous bronze liner. I've had heads come in for a freshen-up after 100K miles and the K-Liners I installed are still within tolerance. That's a good valve guide.
In the standard replacement hard bronze guides the two common choices are silicon bronze and manganese bronze. It's been my experience that the silicon bronze is not near the quality material that the manganese is and the silicon bronze will not live as long. They look the same and machine the same, I wish I knew what the chemical difference is.
No matter what guide you use, remember it is only as good as the guy putting it in. There are still shops out there using dull reamers and fitting them using the go-no-go method. Run the other way!!

 

What were your findings on Phsosporous bronze guides?

 

Sounds like good info to me!!