OK guys, here's what bothers me about this common discussion: Let's just say for the sake of discussion that things change in your personal life a year from now. That car that "I'm never going to sell" has to be sold for some reason. I dunno, maybe you really, really NEED a boat. Or have health issues. Could be any number of things. Anyway, you're talking to a potential buyer. He asks the usual questions about service work. You have to explain to him why certain functions are unnecessary. Take cam seals for instance. He's looking at other cars too. The other car had them done at service, yours didn't. All else equal, which one does he buy? (forgive me for this sidebar, but of course he buys the one with the big t*ts.)
John You are making a great case for just not doing cam timing. That's fine go for it. Just swap the belts. I've seen the nail polish marks from famous shops all over Los Angeles area. Their customers are none the wiser. If it works for them it can work for you too. The only minimal requirement is that you be near /on the factory assembly marks and the car will run. It takes me many hours to pull the motor. It takes another couple to cam time. Cam timing is a minority percentage investment in overall major service. I don't get paid by the hour so I'm perfectly happy to time my Ferrari the way Ferrari intends. Ferrari has a very specific proceedure and there are other ways that work in theory. I have done them and even posted about them. Your comments on TDC are part of them too. Years ago when no one posted about cam timing procedure I posted one...a simple one using lobe centerline and assuming symmetrical camlobes. That method put the timing marks dead on the assembly marks on the particular Ferraris I was working on. RifleDriver at the time would not or could not tell me why my method was wrong yet yielded the right results. DaveHelms at the time said what I had done was a "good start" but also could not explain why I was in error yet yielded the right results. I continued to go with my method because that was a bonafide chevy 350 motor method and it worked. The Ferrari way did not make sense and I wasn't going to spend the time to figure it out or understand what they were trying to achieve. Then Pete on the 550 board really tried to figure this out and I followed his work and decided to figure it out and do it the Ferrari way. All I can tell you is what DaveHelms and RifleDriver already knew that a new level of cam timing accuracy was to be achieved. It becomes blatantly obvious when you go through the Ferrari method for your model and experience how visually imperceptible movement on the cog greatly changes what is required on the dial gauge. Any old engineer will tell you engineering without experience does not account for much. As humans we add or leave out details to sell our ideas. Math isn't wrong. Humans just naturally add or leave out details to be convincing. So yeah "acedemic BS". What happens is some small stretch, some small wear, some methodology uncertainty, some mechanic experience, some mechanic "on the clock" haste, some questionable choices, some 10 belts changed over nearly 25 years. I can guarantee you per Ferrari your cam timing is off. You bought a Ferrari. Ferrari tells you to do certain things so your Ferrari acts like a Ferrari. Why do we continue to have these silly discussions?
Yes but it take experience to know if you need to "use" 2+2=4 or 4/2=2. That's why you you engineers work as teams to solve problems and the guy running the project is some old engineer not the hot shot with newly minted degree. Dave we can never agree on anything. Sub in me for John and you would still be arguing about TDC and Con rod length...LOL!
John about your last point when I was taught to time my motorycycle engines we went both directions on the crank and I did not know why. Likelt this was to take the bearing tollerance in to effect. Then of course we split the diff for tdc
Thanks for a thoughtful reply. But if you can guarantee that my timing is off because the last guy who timed it didn't get it right, why should I believe the next guy will? That's just an argument for leaving good enough alone. And sure, experience is great, but cam timing isn't exactly high tech. It's what an engineer would call a previously solved problem. And frankly, all the experience in the world, while making the job easier, doesn't mean the guy doing it has a clue about why he does what he does. He is just following a set of directions. He may know the process but not understand it. Yep, the discussions are silly because we will each do as we please. Be that as it may, I'm sure many readers now have a better understanding of cam timing and what effects it and by how much. Are the old seals leaking?
Carl, experience is not linear with results and quality. A couple of my own examples: I've been playing guitar for over 30 years, while off and on, I have a lot of experience. Yet, this young girl (now older) clearly has less experiences than I do and she can mop the floor with me On the other hand, I started my business at age 26 and beat out many companies in business for years But, let's get back to John's point.... For the 355, Ferrari originally has 15K mile service intervals. When time intervals were released, that was due to belt changes and nothing more. That said, one would not need to time the engine every 3 years when doing a belt change. Now, lets assume you bought a 355 new and did a belt swap only every 3 years. At the end of say 12 years, nothing else done (in theory) aside from belt swaps, please explain to me how the timing would be off, hence requiring the motor to be re-timed? Please tell me what components would cause a change and why? John has asked for an open exchange and discussion yet the responses are "academic BS" and "experience" - sorry, that's not constructive to a discussion and that is why you and I will likely never agree
Some would call an Engineer using a formula for stress on an "I" beam as "just following directions." Experience is but one adjective to describe one's potential for success. Your OEM Ferrari degree wheel just gather's dust in a prominent place a fixed on your shop wall? If you assume no one will time your car better than the day your car was born at the factory why isn't the factory belt change procedure just to simply count the number of belt teeth between respective cogs? We will never agree. I'll just continue to do it the Ferrari way...
My motor is a total rebuild - that requires re-timing. The Ferrari procedure is for timing, from scratch. I don't recall ever reading that the procedure is for belt changes.
The difference is that the engineer knows where the formula came from and if you present him with a beam with a new cross section he can derive the correct formula for that cross section. A technician applying the formula could, and most likely would, be the one to compute the stress for the I beam, but would most likely not have the knowledge of its derivation and given the new shape would be at a loss. Tech: "Hey Mr engineer, how do I compute the stress for this beam?" Engineer: "It's academic my dear friend." I love it when you guys dump on engineers when you discuss cars designed by them. And whether you believe in constantly timing your cams or not, it was the engineers that defined the specifications and procedure for doing so. Damn engineers! No wonder you can't time a Ferrari correctly WTF do that know about cam timing? Merry Christmas kids. Santa is on his way. Time for me to put out the milk and cookies.
Your statement is wrong. Read the manual. You just can't do parts of the major completely without cam timing everytime. If what I say makes no sense here is your own research from your TDC thread right from the master mechanic himself on a Ferrari making well under the 100hp/liter the 355 makes. <<"On those motors the cam timing doesn't have to be off a great deal to cause those problems. That is why the procedure is to degree in the cams every time and not to just align the marks.">> https://www.ferrarichat.com/forum/posts/134481568/ Good night!
Nope. If nothing other than the belt is changed, no need to retime. If you think otherwise, you simply don't understand geometry and I can't help you with that. Yep, I read the manual. It talks about engine assembly, not belt swaps. But, the 360 manual does and shows a lock and swap.
I have had two Major Services done on my 1994 348 TS Series Speciale since I owned it. Both times the final bill was around $12K. The first time (2012) the additional things it needed were a water pump, valve guide seals, fuel injector cleaning, valve covers repainted, etc. The second time (2017) it needed a clutch, One front wheel bearing - NOS way unavailable overpriced part, Heater valve was leaking we found a used Ferrari piece (It was a actually a VOLKSWAGEN PART), I had the drivers seat re-dyed on the bolster, I also had the shop remove an aftermarket alarm system that seemed to be going bad they fixed a bad ground on the engine lid that caused the third brake light to not work. I'm not sure if I will keep this car through another Major Service. I love the car and will need to decide if I want to stick another $12k in it again. I really do not do much except normal oil changes and maintenance in between. Very reliable and fun.
Ah Dave major difference between the 360 and 355. The 360 timing can be verified prior to the belt change. Read using the Ferrari SD. Tolerance is very tight. If the timing is within tolerance, lock and swap. If outside allowable tolerance, timing required. As you are aware, 355 does not allow timing verification prior to belt service.
When I read things like this I am compelled to ask, 1) by what measure was it determined that it needed valve seals? First time I've heard that one. Were there symptoms? 2) similarly, did it need a new clutch as evidenced by issues with driving, or were you told you needed a new clutch? I ask be cause I was told I needed a new water pump and a new clutch at my 308 30 k service. I said no. 7 years later I'm still on the same water pump and clutch with no problems to report.
Hi John, perhaps you need a new tech! I used to do all my own work. Majors on my then 308, 348, 355, Porsche 911s, 930s etc. Now that I am in my mid sixties, the knees and the back are not as eager! The techs I use here in The Peoples Republic of MA clearly show why anything outside the normal service is required. Waterpump weeping, clutch slipping or no adjustment left due to wear. Evidence of impending failure.
Maybe I wrote that too strongly. It was suggested that I replace the water pump and clutch. You know, while we're in there. And I agree, if it's bad, show me! Plus, here in CT the shop has to return any old parts to the customer if requested. If there is a core charge, the customer is responsible for it if he requests the old part.
That's not what the WSM says. It says the marks should line up. If not, retime. Of course, there is the question of exactly what "line up means". And what about seals that are commonly replaced with belts. Not so much with the 360.
As you are well aware the Ferrari WSMs are filled with contradictions! My understanding, the marks are for reference only. I have mine checked on the SD to insure correct timing etc. The techs put the 360 on the SD to check for pending and shown codes etc. Clutch reading, timing etc all available. The water-pump is far easier to access on the 308. The clutch far more difficult than a 355. Did Ferrari recommend updating the 308 water-pump to the 328 unit? Perhaps that is the basis for his recommendation.