VALVE GUIDE REPLACEMENT?

You don't say what year car. If it has bronze guides with what we have seen happening in the last couple of years I would say yes.

 

My '97 with 37K miles is pre- 'new' valve guides, did engine out 4 months ago, leakdown numbers show no problems at all. Not going to change them out.

 

what new?...I have a 98...guides went bad 20K miles...Somebody needs to post a picture of the "new guide" I would like to see that they exist!

The Bobert

 

Keep your old valve guides. Take a picture of them with your new guides on a plate or temp rug covered by a current newspaper with date showing in your empty engine bay such that your VIN is visible. Print out the picture and store it in your log. Tape a copy of the picture to a clear bag that holds your old valve guides.

From then on you will *always* be able to show that you installed the correct new valve guides...even to a raving skeptic.

 

I posted a thread on here a few weeks ago, http://www.ferrarichat.com/forum/showthread.php?t=139185 on this very subject. I attatched several pics showing different guides and how they're replaced. Like Rifle said, if they're bronze, they will eventually fail. They used them as late as 98 but started phasing them out and converting to iron guides in 96. There's also more info on my site at www.FerrariPerformance.com Let me know if I can help!
~Rob

 

Based upon everything I have seen/read and that has been posted on this web site, I do not beleive that Ferrari ever changed the guides in the 355. I think that the "changed guides" is a sales technique that is used to sell the cars. If they really did change the guides, then why are we seeing 98's like mine with the old guides?

Like they say at Indy their are those that have it the wall and their are those that will hit the wall! If you have a 355 and the guides have not been replaced...tick...tick...the clock is running down on you!

If you own one that the guides have not been done then I would start setting some money aside for the repair and just plan on it when you get your next major done. Then at least you won't go into shock when they give you the news!

The Bobert

 

You are wrong.

We just told you, just like a hundred threads and a thousand posts before.

 

You are thinking like an American or German, where assembly processes...work processes in general, are formal and set in stone.

Ferraris, however, are Italian. Italians have informal work processes, maybe even a glass of wine at lunch.

If old valve guides are laying around when the case of new valve guides is used up on the assembly line, it's easier to just use the old ones rather than go get a whole new case of the right valve guides...so the bronze valve guides get slapped into that car and others until somebody finally brings in a new case of the right valve guides again.

Then the right valve guides are installed by assemblers until *that* case gets used up, and the cycle repeats.

So you get batches of cars made right, and batches made with the wrong valve guides. The assemblers go have another bottle of vino and life goes on.

Italians enjoy **feeling** life, Americans and Germans enjoy **knowing** that they did the right thing.

Of course, this is painting with a broad brush, which is unfair, yet more accurate than not even though exceptions abound in large numbers to the "rule" listed above.

 

I agree with this to a certain degree. What a lot of people don't know is that there are two different cylinder heads also. The bronze guides have a large flange that sits in a counterbore so the top of the flange is flush with the spring seat. The iron guides have no flange and so the head is not counterbored for it. Therefore, the flanged bronze guides will not go into the heads that have iron guides without being modified. See attatched image: Shown is the iron guide, the stock bronze guide and the replacement bronze guide, then the second pic is how I modify the flanged guide so it will fit the head that the iron guide came out of. There is just enough of a chamfer at the top of the guide bore to allow for the bead I leave on the guide.
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Nice pics! Are the 'bronze' colored guides in the pics all the same alloy? Are they all by the same manufacturer? I would like to know who makes which ones if you can say .

 

Hey Oz, well since this is how I make my living I'd rather not say who's guides these are. But, the 'bronze' colored guides are not just the same alloy, they're the same guides. I start with the flanged guide and machine the flange down to a .050 bead so they will fit the heads that had the iron guides and are not recessed for the flanged guides. They are manganese bronze, one of the most durable IMO.