Caught you at what? I don't understand your post, especially the valve guide fantasy part. Please explain.
You seem to have much more knowledge on the subject about 355 valve guide issues on here than anyone else. Every time a post is started about the issue, you always blow it off as thought it is a fantasy. One post, in reference to the issue, in which Dave Helms seems to have set you straight, you were quoted to say that "355 owners have been led down a path of false pretenses as far as header problems and valve guide issues, you guys deserve better". Something along those lines. Of all the 355 engines you have personally rebuilt, how many have you found to have guide issues? People want to know potential problems with a certain model of car, and I won't hold back, early 355's HAVE a guide issue!! You seem to be hell bent on establishing a % of cars with valve guide problems that were either this or that, or used this kind of oil, or were driven to church on Sunday by a little old lady....... it doesn't matter. Soft valve guides will fail no matter what the common denominator may be.
It's true that I said something like the above, but you've taken it out of context. I was making a larger point: #1. many 355's do have a valve guide issue, but #2. a lot of 355's do not have a valve guide issue, and #3. a few 355's without valve guide issues have been sold a bill of goods...as if they needed a valve guide repair job when their motors weren't smoking in the least So I'm not running around saying that 355s will never have a valve guide problem...but rather...I'm saying that your motor had better be smoking before you pay for a valve guide repair.
I agree, but I'm not one to sell someone something that's not needed. I wouldn't doubt that somewhere along the line, a 355 owner was sold a guide job that wasn't needed. I'm sure there are a million things that unknowing owners have been sold that weren't neccessary. Like the housewife that was sold a radiator flush and fill on her 72 VW . That's why owners need to be informed about potential issues. Smoking may not be the tale tail sign, but leakdown numbers and oil goo in the exhaust port when the headers are removed are a sure sign of problems. I wouldn't base my diagnosis of valve guide issues only on whether the car was smoking or not.
NO NO NO MR. Enginefxr Here is the chain of events Smoking exhaust = Bad guides = Lawsuit...........Enough said Image Unavailable, Please Login Image Unavailable, Please Login Image Unavailable, Please Login
Good points, and I also trust that you didn't think that I was accusing you of shady business practices. Perhaps what you and I have said above could be refined a bit: If a 355 owner is told that she needs a valve guide job when her 355 isn't smoking, then either a second opinion or else an inspection of exhausts ports for "oil goo" would be prudent to perform prior to just ponying up the coin.
Or an inspection of the intake track / valves. I have yet to see one smoke as a result of a guide problem. Hugh is right on the money regarding the Cats. Dave
Does that have anything to do with 355's having hydraulic lifters? Can you help explain how a 355 wouldn't smoke if it has valve guides that are no longer original shape/distorted? Can bent valve guides somehow maintain an oil tight seal (and if so, why would you need to change them out)? When I bent valve guides on my 348, it smoked like a Kennedy after Marilyn Monroe spent the night...
So If I pull a spark plug on a 355 and squirt a few drops of oil directly into the cylinder, upon reassembly I'll see no smoke from the running motor because the cats vaporize it all?
I am amazed that ANY of the real experts are still bothering with this forum. there used to be so much useful information available to everybody here but now most of the good guys have left. Keep threads like this up and no doubt we will lose dave and everyone worth listening to as well.
I don't really understand this issue except to know that long after this thread is history some form of it will rise again! My thinking is that the engine leakdown test is the definitive test for engine health everything else is just a symptom with possibly multiple causes. As a home mechinic my knowledge is not deep so to me everything starts at the basics and that's compression and timing. Everything else is just a bolt-on. Also, what do you see in 355 intake tracts? I would expect "oil" in the tracts as a result of designed operation from the PVC, not valve overlap reversion sucking oil. I assume 355's still use a PVC system of some kind burning steaming oily engine environment and dry sump oily air into the intake. The only way I could keep my intake clean was to add an extra catchcan. This is a common problem on just about every modern car run on racetracks with modern PVC systems and I have just delt with that on my Z06 thinking about becoming a dedicated track car. I have seen the most Ferrari smoke from drysump cars that have been overfilled. But I also thought that start-up blue tailpipe smoking was a classic suspected bad guide issue in the generic car. 355's don't get the classic smoke because they have really great valve seals or the flow reversion is really big???? As I have heard the Ferrari solution of the "steel guide" seemed to stop the issue as once fixed the cars do not seem to have a problem again. Is there any data to support using the classic bronze-manganese or beryllium-copper guide from a quality aftermarket company like a DelWest? Or was it Ferrari's idea to just not screw around and end the story by bringing a gun to the knife-fight and it is "US" who keep beating this dead horse keeping alive an issue that has been long since solved?
Do 355s not smoke when new owners overfill the oil sump after not knowing how to check the oil level (i.e. with engine hot, not cold)? Do 355s not get oil into their intake ports through their MAFs when they are overfilled with oil? Am I to understand that 355s have incredibly efficient catalytic converters?
Of course they smoke under this condition. Massive amounts of oil put into the combustion chamber all at once. The inspection of the intake track is to identify the amount of carbon on the back of the intake valve. I have seen the build up to the point where it is packed smooth and shaped to the intake port. This then resulted in zero air flow until the valve was near full lift. Most often the valve seal is still intact on the ones I have done. A valve stem seal is designed to work within a fairly narrow range of off set. Most often the amount of wear is not worth even measuring with a bore gauge. Holding the valve at its full open height, the head of the valve is able to be moved back and forth near 3/8". Even a perfect condition stem seal is unable to do its job at these extremes as it is working on a 6 mm stem. At high RPM the valve, now not accurately supported by the guide, is able to bounce around and allow a small amount of oil past the seal on each revolution. On the intake side the valve runs cool enough that this oil forms deposits on the valve. Often the center valve looks quite good as the injector sprays directly at it, washing the back side of the valve keeping it free of carbon. Very small amounts of oil, at higher RPM with an efficient HOT Cat and no, you do not see smoke on the majority of the effected cars. As the valves are acted on by a well supported cam follower pushing straight down (i.e., no side load), often the valve will seat properly in the valve seat creating a proper seal. This is why it is difficult to duplicate a compression / leak down test results from one time to the next on engine effected by this failure. Maybe the valve sat squarely in its seat, maybe not. The tendency is to seat properly at low RPM due to the follower design which would result in a proper leak down reading. Having 3 intake valves, the 2 outer ones can be completely plugged up and still the center valve (washed clean by the injector) can supply all the flow required for a good compression reading at cranking speed. Choose to believe what I wrote or not, makes no difference to me. Accuse our profession of misleading owners because you do not happen to understand the dynamics of a problem and I am all over it. I earned the knowledge I posted above, you got it for free. No one paid me for the many hours I have spent in an attempt to fully understand the dynamics of every failure affecting these cars. Was the header problem a cause or a result of the guide problem or the liner problem or was it a completely separate stand alone issue? Personally I believe I now understand the chain of events, the causes and the final remedies for these issues. It is an ongoing situation of predicting future failures resulting from "repairs" that I feel falls short of addressing all the issues at hand. I assure you, I for one am not smart enough to begin to think I understand all of these problems in their entirety. I have on the other hand been down and dirty testing, measuring and taking notes for countless hours. I have notes of every cam timing setting I have used since 95 and all of the engine parameters on each car. Have you ever touched a 355 head off the car? Scanning the Net for data can be a highly flawed method of education if you believe everything you read. I suggest a retraction of prior statements you have made regarding this situation is in order. And with this I end my final attempt of dealing with educating you regarding the 355 issues, in a politically correct manner. Dave
Hey Dave, I appreciate your elaboration above. I don't know that I could explain to someone else, if they asked me, why a 348 with bad valve guides will smoke like a napalmed tire depot, while a 355 apparently won't. So I'm not trying to paint you in a bad light or cast aspersions your way, I'm really just posting my own bafflement. I'm baffled, confused, bewildered that 355s apparently don't smoke with bad valve guides. I realize that you just tried to explain it to me above, but for whatever I can't pull out of what you said something tangible like "355s have hydraulic lifters which make them different from 348s that don't in regards to smoking." So I apologize that it isn't soaking into my head...the "why" or "how" part of 355s behave differently. To me, a 355 with bad valve guides should either smoke or else not need a valve guide job. Are people getting valve guide jobs on 355s merely to bring back power lost by carbon fouling on 355s, or are they correcting a fundamental operating problem (e.g. improper valve to valve guide contact, oil consumption, etc.)?
If you bought one, you could then become the world's expert on that as well as 348s. All of us "hack" pros could go back to our business instead of trying to help y'all
I've got $100 that says that I've helped more people here than you. No one's begging you to stick around, either. Perhaps my questions are just hitting a little too close to home for you. So tell me, how many 355s have you given a "Valve guide job" when their motors weren't smoking?
I see some carbon on the back if intake valves when engines run well too and have no experience with what is excessive. Having no feel for how much is too much but knowing you really do not want any...your second paragraph is concerning. The only way to get more accurate with the leakdown test is with camshafts off and include a wiggle to the valves under the buckets. Before going that invasive , is a Vacuum test showing "fluctuations" a reliable indicator in a 355 which would indicate the problem?
Here is a picture showing what Dave is talking about. Note the black outboard intake valves, as the centers have been washed clean with injector spray. The amount shown is "excessive". A person could keep driving an engine with bad valve guides, as long as you don't mind it ruining your valve seats and valves, but the problem won't get any better. Just as you could drive an engine with a spun rod bearing, as long as you don't mind the knocking......or care if the rod eventually comes out the side of the block. Image Unavailable, Please Login
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That's a *lot* of oil/carbon buildup on the intake valves. Seems like that much oil going in to the combustion chamber would have to smoke as much in 355s as in other models of cars. And I'm curious why no "valve cleaning product" like Techron would do to the flanking intake valves that which the fuel injector is doing to keep the center intake valve clean. You also posted a pic of an oil-fouled 355 exhaust port. Oil out the exhaust port would seem like a good candidate for making smoke bellow out of a 355, as well.
i've seen a 355 with guide issues that blew no smoke. it only came to light because of sudden consumption of oil, where it never did before, and a subsequent leak test. once stripped, you could feel the sideways movement in the valves. obviously the worse the wear in the guides, the more rapidly it deteriorates. if your 355 starts consuming oil, fix it quick! the last thing you want is for something to break.
