When did Ferrari update F355 valve guides

There is no definitive point. It has been reported that an owner of a Fiorano edition (last of the '99s) found bronze guides in his heads.


Rob

 

Are you sure the change was ever made? We thought the change to sintered steel was made on the 456M because the 456 suffered from the same problems as the F355. We later discovered the change was never made and bronze guides were fitted throughout production, even though production did not end until 2003. The 575M was the first of the V12s fitted with sintered steel guides in late 01 as 02 models. All the 550s had bronze guides, too.

If they were changed to sintered steel, the change was made at engine number 48002 according to the parts book, so a few of you should be able to determine what that engine number corresponds to for serial number.

 

some experts on Fchat have said around mid-'98 build dates they were changed but a hard S/N was never established. Yes that Fiorano owner said he had bronze...but the other expert independents will say they've never had to replace guides in mid '98-99 cars. FWIW my '99 is running strong at 46k+ miles with original guides

 

If you search this section, you will find the general feeling that early cars had them and later cars did not - maybe. Mostly the transition is cited between 1998 and 1999. Some people think that the factory guys just pulled whatever parts out of the bin to assemble the engines. It's all heresay and no one really has a straight answer. Also, the story of them going bad is based on isolated experiences. There are the vast majority of 355s built with bronze guides still running around with them. If the car passes a leak down, who cares what the guides are composed of?