Yellow Bullet Forums banner
1 - 18 of 18 Posts

·
Registered
Joined
·
1,574 Posts
Discussion Starter · #1 ·
I'm in need of guides/valve job on my F355 heads. The stuff is tiny. One angle valve job for whatever reason. (needed to pull heat out of tiny valves? I dont' know)

Any recommendations for a shop that would be best for this?

I know most are likely capable, looking for who would be the best/meticulous. Attention to detail is my priority, not cost.

Thanks!



 

·
Registered
Joined
·
6,581 Posts
Might contact a higher end motorcycle shop. They will likely be the most experienced with those, as a lot of bike heads come with 5 valves. They may also be able to guide you in respect to valve jobs. At least, that's what I would do.
 

·
Registered
Joined
·
2,839 Posts
George Bryce?
 

·
Registered
Joined
·
1,248 Posts
If I am not mistaken, Chris Frank does these heads (may be lambo heads) none the less he also does ford modular and the M8 HD stuff too.
 
  • Like
Reactions: ndmp40

·
Registered
Joined
·
1,592 Posts
Any briggs weed eater shop should be qualified to work on those glorified Volkswagen engines.lol.Honestly they are nothing that anyone with good equipment and experience could handle.The guy I bought my engine equipment from does bike,porsche and about anything out there.You probably have 8mm stems which most shops should have a pilot to fit those guides.
 
  • Like
Reactions: DarkMatter

·
Registered
Joined
·
3,041 Posts
I've seen and Know Greg G does some older high dollar Vintage European head work...
 

·
Registered
Joined
·
1,574 Posts
Discussion Starter · #12 ·
Any briggs weed eater shop should be qualified to work on those glorified Volkswagen engines.lol.Honestly they are nothing that anyone with good equipment and experience could handle.The guy I bought my engine equipment from does bike,porsche and about anything out there.You probably have 8mm stems which most shops should have a pilot to fit those guides.
I thought the engine in my 993 was closer to a glorified Volkswagen.

Valve stems are 6mm.
 

·
Registered
Joined
·
1,309 Posts
If the valve guides in the heads now are bronze.....it is best to core drill them about an inch deep from the valve pocket side, leaving about .030" wall thickness, then make a punch that fits into the new hole and tap the old guides out. I've seen a few guides that galled on installation at Ferrari (forgot to lube them?), and if the machinist tries to punch them out normally it will swell the tip of the guide larger than the guide hole bore and enlarge the head. If the guides are steel, they should come out easily without doing any of that.

Make an installation tool in the lathe that consists of a driver that contacts the junction where the seal portion of the guide meets the main body and a bushing that fits tight in the bucket bore and centers the guide and driving tool. The seats will come in quicker.

If you are willing to put the seating angle right out to the edge of the valve you can get a bottom cut on both seats, which helps flow somewhat. I did that on the Challenge heads many years ago before they had to start sending everything back to Ferrari for maintenance. It was worth 10 rwhp.
 

·
Registered
Joined
·
1,574 Posts
Discussion Starter · #14 ·
^ Thank you, that kind of input is much appreciated. The original guides are bronze and have a reputation of early failure. A few years after the first cars rolled out, Ferrari changed the guides from bronze to steel in an effort to fix the problem of premature wear.

Now, nearly 28 years after the first cars rolled out...and many failures..many replacement/offerings are available but bronze replacements said to be harder than original.

Fine, no surprise that's part of the learning curve of greatly increasing operating rpm. What strikes me as odd however is the single angle valve job?

Put all this effort into specific output but be lazy on the valve job? And, seems they put effort into factory port work.

Another thing I should mention is, the valve timing. Center valve is said to open/close 10deg later than the outside valves.

Other than that, I think their efforts towards volumetric efficiency are commendable, for the time. Intake port entry- vertical. Individual throttle bodies. Intake plenums, ram air basically, from corners of quarter windows. Exhaust terminates directly at/above underbody diffusers.
 

·
Registered
Joined
·
3,041 Posts
Yeah I follow some of these guys like a well kept Dog. Told ya GG.
👍
 
  • Like
Reactions: DualQuadDave

·
Registered
Joined
·
2,276 Posts
You will be more than pleased if Greg Good works on your Ferrari heads.
 
  • Like
Reactions: DualQuadDave
1 - 18 of 18 Posts
Top