Setting the cam timing belts on a 355

I dont trust them to stay still. The one bank that is on TDC (firing) will usually stay still, but maybe not the other which has no cylinders at TDC (unlike a 90 deg crank motor).

This is only from my limited experience with flat crank V8, and I will defer to anyone who actually makes a living from it.

JM

 

...and an eery silence followed...



Perhaps not using cam locks is just *really* difficult to explain.

 

Never know when to quit do ya? How about you explain the process to us, with pictures please

 

As a layman, I should be the *last* person attempting to explain how to properly set cam timing without using cam locks.

But this thread doesn't seem to have any experts able to explain it, either...

 

Believe me there are quite a few that can. You need to do a search on the subject and listen to all the crap given when attempts have been made.

 

That's a fair point, but if they aren't going to explain it (for whatever valid reason) then they shouldn't bring it up on their own out of the blue.

Hypothetical: "Oh, there's a great way to time your cam belts...we're just not going to ever specify the technique because someone hurt our feelings 5 years ago when fchat was an email list..."

It gets old. I don't want to hear someone whine about how much their time is worth if it is worth less than mine, and I don't want to hear about great auto techniques if such processes aren't going to be explained...and I really don't care if someone got spanked in some ancient online debate, either.

 

No doubting that!

There is nothing sinister or rocket science about setting cam timing, even Chevrcrap and Fraud race shops do it, they do not open their Summit catalog, order some part because of the wording, then install it by the timing mark stamped on the end.
You need, time, patience, degree wheel, quality dial indicator and the spec sheet and/or shop manual. And yes you would START with the chisel notches lined up and go from there.
As I said we have been doing this for ever on race engines and street Porsches, how else did we get 125+HP from a pump petrol 997cc 4 cyl. pushrod single choke carb engine @ 11,000 in 1969, on points as well?

 

Also, to add confusion to the confused, many race shops set the timing by piston position rather than using a degree wheel. HTH

Brian

 

Yeah, but do they use cam locks?!

 

Yes Vern you are correct but the problem has been that there has been no post I can remember (I do not read them all either) that just said here is how you do it from a pro in one post and let the cards fall where they may. Most posts were dribs and drabs and cryptic from the pros and they may have got jumpped on or are sensitive because frankly this board gives out too much good info for most. With a 20000 FC member base of mostly hobbists it scares the hell out of pros. You got one guy who got the wrong wheels shipped and before the guy even called the Fchat vendor he posted his rant to 20000 people! Geez the poor pros on this list have to contend not only with the resonable Fchat member but also the insenstive and or crazy ones.

 

Just to play devils advocate here.
I know there are mechanics in England who can do a belt change without taking the engine out. Lots of covers and sheilds get left off or bent, but they only charge about $1000.00 for a belt service.
Lets get someone to post "that" procedure.

 

So here is the deal. If you are going to time a motor you gotta think basics. What are you trying to achieve and how are you going to achieve it. Think in your head what the timing events are before you try to time anything. Everything works there is no perfect way just degrees of it. But in general it is most universally believed that precsion of setting your timing and any car would be like this: and who does this:

Most precision_______to____________least precision
Dial guage/valve lift---cam/head marks----cam locks
best pros/racers--basic pros/FNA?/best DIY---most DIYer's

99% of people can't tell which is being done hence the term "consumer acceptable".

 

Just to put you straight, there are ferrari tecs all over Europe that do this. Including official dealers....fact. And what do you base the statement on about missing and bent covers on?

 

You pretty much hit the nail on the head with your comment on the shipping story, great example. What a bunch of crap, this is a good example of a reason I quit posting much here(not that I have much to say anyway) I'm tired of arguing with people on a subject or a proceess that they have never done or have no experiance. Or better yet repeating something that there best friends uncles sister told them or they read on some internet site. My thoughts are if you don't have first hand experiance on the subject at hand then don't comment on the how tos. Save it for the Ferrari discussion forum. When I first joined this site I thought I could pass along 20 years of knowledge on these cars to be of some help to someone, guess again all you get is argument and bullsh@t. A good example would be post #31, knowning when to leave well enough alone instead of shootin' your mouth off. Maybe I'm to sensitive but I guess that's too bad. We have lost a lot of pros on this site because of the wannabe know-it-alls that don't know crap but want to argue with your first hand experiance. Regards, Vern

 

That's it! When you lay it out like that, FBB, you start to clear up the picture for us laymen. See, I was under the impression that using cam locks was what you did to insure that the precise timing that you set was the precise timing that you wound up with after your belt was re-tensioned...but from the above it appears as though you'd just use the cam locks to preserve the old settings (not my point at all)...i.e. the least precise way to time cams instead of the most precise.

So is that really the deal?! Cam locks are for the least precise timing method instead of for insuring the most precision?

 

Vern, there's nothing wrong with post #31. It may just be that some people need thicker skin, which is about the only other alternative seeing as that I'm not going to walk on eggshells to protect their fragile egos.

Be a man. Get over it. You can do it.

 

You see ND this the crap I'm referring to. Never known anyone who loves to here themselves talk as you do. LOL If you would do more listening instead blabbing and insulting people you would maybe learn something about the mechanics of Ferraris, which you most certainly need. An example might be: Are you listening? You won't hurt your head gaskets if you lay across the heads of your engine, I still get a chuckle from that one.

 

Vern, that's a great example! It's still funny.

Not relevant, but funny.

 

To reduce confusion, the degree wheel is supposed to be set to "piston position" and then 100% of all cam timing is based on that.











Of course if you are racing REAL COMPETITIVELY, then you have 8 different TDC and 8 intake btdc and 8 exhaust atdc. You didnt think the crank throws stay 180.00000 degrees apart at 9100, did you?

JM

 

Yes! Cam locks are 100% accurate only IF the last timing was perfect and IF there was zero belt stretch and IF you are able to index the belt into the exact same location, IF the belt is in tension, IF there is not motor wear and IF you are not interested in making sure you have timed the motor right.......at this point why use cam locks when your wife's white nail polish will do just fine? I have helpped several friends do PPI's on prospective cars. One of the first things I look for are nail polish marks. Even the pros have used them.

 

You know, I had never heard of "cam locks" until I came on this board.

Then I saw a really cool fixture made out of Delrin (nylon) and said, "why?"

I've had many customers state how much better their cars (308/328/348/365 GTB/4/365 GTC/4) run after performing one of our "major" services. The reason? Setting cam timing as part of the service.

The reason why is that we don't assume ANYTHING! We time the camshafts as part of changing the belts, which is why I keep encouraging customers to "do the right thing" and not just do "a belt service."

When I started repairing and maintaining Ferraris, I relied on the cam cap and camshaft scribing marks. Then I found when I replaced the belt, often the cams wouldn't exactly line up. So, I learned how to use dial indicators, verify TDC on the flywheel using a piston lock (set up a degree wheel) and use the vernier adjustment on the pulleys to perfectly set the cam timeing to spec.

Personally, I have never used "nail polish," "cam locks" or any other Band-Aid to "put it back together as it came apart" precisely because of my race preparation background. Assume nothing, optimize everything that could be variable.

I'll take my cues from Brian and Dave, thank you very much...

-Peter (timing the cams on a 355 next week)

 

oh dear lord...help us in this time of need.

 

Well Gee that's constructive...

 

The problem was not the timing marks but something more fundamental in that when cam locks are used or nail polish or just marks under valve spring pressure on the camshaft lobes, the belts are replaced without uniform tensioner tension but are taken off under tension. So turning the motor to verify timing allows the tensioners to fully move out and apply their sprung tension since belt tension is not uniform and then the marks are off when the engine is turned and belt tension is normalized. That is why in many post I have said that if you are using a non-wheel/dial guage method you need to lossen cam cog bolts, pin the camshafts with say a matchbook cover to the scribe marks to hold the shafts in place, replace belt, pull cam cog pins out which allows tensioning of the belt over its entire length, reindex the pins to the closest hole in the cam cogs then unpin the camshafts and rotate the engine to verify you are on the marks. This method will not fail and will always be on the marks. The question is do you trust the marks. And since noone seems to want to step up to the plate I'll post how to do it time and patience permitting.

 

First I'll say that Ferrari timing marks in my experience over 20+ years are not miles off like some would lead you to believe. I challenge anyone to feel a seat of the pants difference between the timing makes and the wheel/dial guage method. There are a few cars which the marks are amazingly off so it does happen. If I was a shop guy who did not want unhappy customers I would always use a wheel dial guage. A honda is a more precise motor and their marks are better. I don't know why Ferrari's have problems but perhaps it could be in assembly where they drink too much wine at lunch and use whatever parts are in the parts bin. My 20+ years is not as a fulltime mechanic but as a fairly extreme DIY'er. This is not the only way but it is a good one everyone knows about.

Tools: You need a Degree wheel, Dial guage, piston stop, coat hanger/welding rod, misc wrenches and a good way to attach the degree wheel to your harmonic balancer damper but have access to it to rotate the engine without disturbing the wheel. Next You need to find Top Dead Center of the motor aka TDC. There are 5 ways I know to find TDC. Are you guys interested? If yes let me know otherwise I'll shut up now.