355 Valve Guides

send me your e-mail and I'll send a document I have about this.

 

Maybe do a search- you will find alot of threads pertaining to this... Welcome to the board...

 

Check the threads for the exact date and chassis/engine numbers...but the change did not take place until may/june of 1998. And there have been one or two reports of the guides failing on cars after those dates (though rare).

 

According to information supplied by Tony Palladino, a noted Ferrari mechanic, all F355s with assembly numbers 27689 and higher have the sintered steel valve guides. Any assembly number lower than that will have the potentially problematic bronze guides unless they were subsequently replaced with sintered steel.

 

What is the problem with the bronce valve guides what exactly happens? And why did ferrari change it to cheap sintered steel instead of making a better durable bronce guide?

 

Bronze guides are primarily used in race engines because they dissapate heat faster and much better than steel but the side affect is they wear faster.

 

No but why a , like you called it, racing manufacturing car company wich uses cheap sintered steel valve guides like in a lawnmower? I read here bronce valve guides swap to sintered steel. hollow stem valves swap to solid valves. That are the first steps wich a racing manufacturing car company do in reverse on a normal engine when they prepare it for the circuit. They exchange the cheap steel guides with bronce ones they exchange the cheap solid stem valves to hollow stem or better niomic valves. The change the steel valve seats to berylium bronze seats and so on. Or on engine types where the manufacturer uses both versions in the production process depending on the modelyear everyone is looking for the bronce heads and spend 4 times as much as they would give for a used head with the standard steel parts in it.
But ok it will make no difference on the street driven car. But i doesn't understand it anyhow

Right and for me a ferrari is a race car thats why i don't understand it. Our customers engines run more then 100.000km with bronce guides and hollow stem valves. And if such a small company like ours could do that ferrari could make it with ease.
____________________
Samy

 

Bronze guides may dissipate heat better than steel ones but they both provide enough heat dissipation for the F355. The bronze guides wear much quicker and that is not important in a racing engine where the engines are rebuilt frequently. The cost of a valve job to replace the bronze ones is from $15,000 to $20,000, so you pick.

 

Come to me i do it for 3000$
but yes you're right on the street you won't need it. But its good to have if you won't do something more then that or modify the engine for more performance. And there are many other engines wich run also bronce valve guides stock without problems. Or look into turbochargers also bronze bearings with much more stress (160.000rpm+) to it then the valve guide has to handle.

 

Bruce,
Welcome to F-Chat!!
Fellow Rat Packer, Steve