355 Valve guides

Huhuhuuuu......he said "touch wood" ......huhuhuhuuuuuu
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Yes sir i do on a regular basis (my own by the way)

 

I could accept an issue with a new technology development where Ferrari was pushing the envelope a bit. As you offer, limited production does have it's limitations when it comes to identifying problems that crop-up while product is in the market.

But a valve guide?? Huh? Can you think of anything more basic to the operation of an internal combustion engine? You put a forged crank and titanium rods in a motor that will turn 8,500 revs, and then put bronze guides in it? Complete factory muck-up and they should cover replacement regardless of the mileage.

 

The 355 was the most severe engine on guides Ferrari had ever built to date; 8500 rpm with 5 tiny narrow valves (narrow meaning they have less bearing area against the guide). Also with the massive performance increase over the 348 ( ) it was probably the hottest running engine to date also. Ferrari engineers aren't amateurs, they expected more wear...and as such they did increase the valve guide spec - it was the highest hardness I measured in this analysis:

http://www.ferrarichat.com/forum/showpost.php?p=136907134&postcount=109

Unfortunately time and lots of miles would prove that the guides weren't upgraded enough, and they had to upgrade further to the sintered steel (so I've heard, haven't analyzed one yet) in mid '98 builds.

It makes complete sense that we'd see some failure rate that is way under 100, that's just pure statistics. If it was bad enough that 50% or more cars would fail in owners hands there's a good chance that engineers would have caught that sooner. With their limited resources they tested some small # of engines and maybe all passed for guide wear...it's just that the tested population was too small.

I don't subscribe to the the 'crap material' or 'one bad batch' theory...
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And we are still putting bronze guides in them. We are just using better bronze. There is nothing wrong with bronze, it is an exellent material of which there are hundreds if not thousands of alloys. The factory sintered iron guides are crap.

 

The second owner of my car had the valve guides done in 2002 during a 30k service, at 23000 miles, and well out of warranty (delivered Dec. 1994).

I don't know what the circumstances were but the paperwork indicates that the parts were "goodwilled by FNA" and the labor for the headwork was billed to FNA. So all the valve guides and the exhaust valves were replaced with no charge to the owner (other than the rest of the 30k service).

Maybe he was a very good customer? Curious.

 

Glad to hear someone else shares with my opinion on the factory iron guides!

 

Almost everyone with a clue does but unfortunately that does not include most dealers.

Thet are the same junk made from a different material.

 

Can you clarify this a little? This doesn't mean you haven't ever seen a late '98 or '99 with guides that failed, only that they were steel instead of bronze? I thought I understood there was no way to tell based on production number whether you were "out of the woods" or not.

I just assume it is only a matter of time (early '98 car with 33k miles).

 

I said " I have not seen a late 98 or 99 with bronze guides". I really do not know how to better clarify that.

 

Brian- Manley valves, I assume their custom ones, are what you said you use on Ferraris. Where do you get the valve guides if it is not a secret? I checked Manley's catalog and did not see anything that looked close.

Taz
Terry Phillips

 

Have you seen '98s or '99s with steel guides fail?

 

Of all this talk, I haven't seen anyone consider the comparison of guide wear to driving style..

OK here are two scenarios..

Easy life, turning between 3 and 5k rpm for 95% of the engines life in a moderate climate, on long runs, with the perfect oil, being warmed up carefully and driven with mechanical sympathy .. 40000mi or more guide life??

vs

Hard life, turning 7-8k rpm for 90% of it life in a smoking hot climate in city traffic, with the wrong or dirty oil, being driven like it was stolen from the first 30 seconds its started, driven by an idiot ... maybe 20000 mi or less guide life??

Doesnt this kinda make sense??

I somehow feel that the guides in the 355 are getting a bad rap. I am sure they are, for the most part, quite decent, albeit asked to deliver a lot, being in the 355 engine.

Im not a Ferrari guru, but IMO, from my observations, a performance engine that has lead a good life, has been well cared for, and driven with respect should see maybe 40k mi life out of a set of guides.. to expect more is, in my opinion, wishful thinking.

So figure on 20-40K mi of guide life and figure out which end of the scale it is likely to be in by doing an in depth service and owner history.. talk to every PO of the car and then maybe you'll have an idea what to expect.

Thats just my opinion... I could be wrong Jan

 

For my F355B, its a 95 with bronze guides. It currently has 57K miles on the clock and 5K of those miles have transpired on race tracks. I got the car with 22K miles and don't have a history before taking posession, although I do know previous owner. On those 5K race track miles and at least another 5K back road miles, the perverbial snot has been run out of the engine, including at least 20 minutes over redline. However, it has always had the oil warm before any of this transpires. The rest of the milage is typical hiway cruising. It still runs like new with excelent leakdown numbers.

A number of years ago I ran some oil experiments at those race tracks in 103dF heat including using 5W-30 oils (HTHS > 3.8) with no ill effects (in fact it runs rather well on 5W-30 Redline). But I digress.

My own read of this situation is that the problem is a good part owners not letting the oil get hot combined with marginal original materials, and maybe a bit of spotty maintenance.

It becomes such a hot button item because of the cost to fix the problem ~$15K+ is excessive compared to a $1K charge for a Vette with a similar issue. Now with the value of the F355s dropping into the ball park where a valve guide job might be 1/3-1/2 the value of the car itself; it scares potential new owners away. If you cannot afford to pick up the tab for problem areas like this, maybe you should reconsider owning a car such as a F355. Since they are a decade out of warentee nobody else is going to pick it up for you.

This is the price of driving real race cars.....

 

[For my F355B, its a 95 with bronze guides. It currently has 57K miles on the clock and 5K of those miles have transpired on race tracks. I got the car with 22K miles and don't have a history before taking posession, ]

>>Any chance it had the guides done prior.. and you are nearing the 40k mark??.

[This is the price of driving real race cars.....]

>>Agreed.. it is that!

hmmm... 5-30 Redline? I was considering RL 10-40 next OC??

 

It seems that I am due now ...
What is your recommendation on the best guides to use now on a 355 (brand, where to buy, ...)?
Thanks

 

It was a single measurement in a series of oil tests of 15W-50 through 5W-30 oils on race tracks in the midst of Texas summer heat. The 5W-30 Redline has an HTHS number of 3.8 which is good enough at 285dF to be as protective as shell Helix 10W-40 is at 305dF. I tried it, it worked (under the caveat that your oil does not get hotter than 285dF.)

I am currently running a 5W-40 oil with an HTHS of 4.2 and a big dose of ZDDP.

 

Perfect post. I never ever start it and drive it. My oil is never allowed to get dark. I hang out at the shop where my car gets serviced and I have seen the oil come out of some Ferraris, Lambos and Porches that looks like its coming out of a diesel locamotive. Its really sad that these cars are treated like that. Thats why you only buy these cars from people or through mechanics that you know. I just had my engine out service and the leak down was crap. I still had power and never burned oil, but since the engine was out and the guides were bronse, we did the heads. It has more power now but I did other stuff to it so I cant really tell how much was due to the valves leaking. I believe that the guides tighten up quite a bit when warm. The leak down was done with the engine cold. I was amazed at how there was no wear in the sleeves. There was no ridge whatsoever at the top of the stoke. Here are just a few pics of the hundred or so I took.
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I have a picture of the bottom end of my F355 engine from the 52K mile point. I can't post it because I have run out of upload area. However, it is instructive at how clean this engine is inside; that is if you could see it. I suspect it is from the 3K mile change interval with the additional rule of a change after each race weekend, and the use of premium synthetics.

I also have a picture of the back sides of the intake valves from my previous major at 42K miles showing absolutely no carbon on the intake vavles (stems,...)

By the way, mice job on getting everything really clean.

 

Thanks.....The 355 is an amazing machine to drive.

 

how do you know when the guides need to be replaced?

 

Start with an engine compression and leakdown check. If there's a problem, then start investigating the cause.

 

If you're using up too much oil.

Then I'll order a Compression Test AND a Leak Down Test to verify numbers.

 

Bad compression #s will suffice. A leakdown test after the compression test yielding bad #s just tells you (or may tell you) why the compression #s are bad. Still a good idea to do the leakdown after the bad compression numbers.

But if the compression #s are good, then the leakage #s will have to be good.

Don't forget you can have good leakage #s and still have bad compression #s.

 

Okay I'll indulge the inevitable question and give a brief demonstration of the relationship between cylinder leakage and compression. A little 8th grade logic combined with prior knowledge.

Good compression #s --> Good leakage #s
[If the compression #s are good, then the leakage #s must be good.]
TRUE statement

Good leakage #s --> good compression
[If the leakage #s are good, then the compression #s must be good.]
FALSE statement

Bad leakage #s --> Bad compression #s
[If the leakage #s are bad, the compression #s must also be bad.]
TRUE statement

Bad compression #s --> Bad leakage #s
[If the compression #s are bad, then the leakage #s must also be bad.]
FALSE statement