Cam timing Alignment Question - See Photos

my 308 is in for timing belts and i am requesting that they degree the cams. From what i understand, those marks on the caps and camshaft are just ballpark so there is no interference. i would definately use a degree wheel, or use the flywheel to set the intake and exhaust cams (i think each tooth is 2.7 degrees on the flywheel). On my car, those marks on the caps and camshaft ware well enough off to make a difference. also my TDC mark on the flywheel was off by almost 2 degrees - so maybe use a dial indicator to set TDC off #1 piston, and adjust the pointer for TDC. my car is a euro carb car, and we are going with the euro spec for the exhaust and the US spec for the intake. Dave Helms is setting up my car and i highly respect his advise and skill when working on these engines. According to dave, the superb running 308s are those that have been setup properly by degreeing the camshafts and not using the factory marks on the caps and camshafts.
john
78 308 gts euro

 

I've been helping a friend tear down his 308 engine for a rebuild and yesterday we worked on removing the heads. When we looked at the cams, we found exactly the same thing, a slight variation on all four of the cams from the scribed marks. One of the cams was off by more than the others. But the engine had been running well prior to the teardown. When it goes back together, he will be using a dial indicator to set the timing, not those marks.

 

Hello,

these marks on the cams are set by the factory after setting the timing spot on with the help of a flywheel. Not at all just a rough check of the timing. For this there are additional marks on the cam pulley flanges.
I aim for zero variation between the marks when I have my cambelts and covers off.
Last time it made a noticeable difference in how my engine was running.
If you want the best, adjust your pulleys.

Best Regards from Germany

Martin ( carbed Euro 308 GTB )

 

Martin, On a 1 inch diameter camshaft - can you really see if the marks are spot on with the cam caps? there is not enough resolution to see even 4 degrees by setting it up this way. for example, being off by just a millimeter or less can equate to several degrees. thats why degree wheels are used, or use the flywheel to degree the cams (much more resolution). I will post pictures of the cam caps marks in relation to the notches on the cams when i get them from Dave after he degrees my cams. bottom line, its your car, take the time to do it right the first time and know that it will always be spot on, note the new marks on the flywheel and be done with it for good. by the way, Dave is advancing the whole timing by an additional 2 degrees to allow for belt stretching - which will eventually retard the timing.

 

assumed the diameter of the camshaft is 1", 1mm would be 4 degrees ( on the camshaft, not on the crankshaft ) and this is clearly visible. Even less, though I'm wearing glasses .

Best Regards

Martin

 

I just finished my 30K service and as a part of this service, we re-degreed the cams. My cam / cam journal marks were exactly like yours at the start with the flywheel at TDC. All of my cams forward and rear were off by about the same margin.

The first thing we did was to fit the new belts to see if that brought the cam & cam journal marks closer together in relation to flywheel TDC. It helped, however, the cam / cam journal marks were still off (E.G. not within the goalposts as we called them...). We removed the cam sprockets and fiddled for about an hour on each bank to get the cams degreed properly within spec (removed the pin and reset to a different hole). Made a huge (HUGE!) difference once we started the car.

The forward bank was a little tougher to do since we relied on a mirror and light (and we double-checked each others work...).

 

Ferrari uses a degree wheel on each and every motor they build. When they are done the marks often do not line up perfectly. The marks on the caps and the marks on the cams are not made by the assembler, they are made when the parts are made. On the late model cars since about the TR/TR512 there are hand made marks at the back of the cams (the crooked ugly ones)
that ARE put there by the assembler so that in the event of a problem during testing, if the motor requires partial disassembly he can reassemble with out going to the trouble of redegreeing the motor.

If you spend enough time in the engine department at Ferrari you will see all this being done. It, at the manufacturers level, is quite time consuming and I suspect that Ferrari would not bother to spend the time or money to do it if it did not yield results especially when you consider the engine building process is the one in house process that can and does tie up the assembly line. Timing is of the essence in the engine department, they don't waste time.

 

Hello,

this is quite the opposite of what I have watched and what I have discussed with a Ferrari workshop over here. Not on the cam bearing caps, but on the camshafts.

Best Regards

Martin

 

Go to the factory and watch.

Your information, while well intentioned, flys in the face of everything Ferrari says and does. While it may work for you it should not be represented as the way Ferrari does it.

Also if you look at the cam the notch is parkerized. That process is part of the manufacturing process and could not have been done during engine assembly.

 

what's 'parkerized' ?

 

Black "coating". Part of hardening process.

 

The cuts that are the cam degree marks are very precise, the bottom of the marks is square, most likely they made with a slitting saw. This isn't a case of guido whacking the cams with a cold chisel wherever seemed convenient, or while assembling the engine.

This precision along with the parkerizing (or heat treating darkening) makes it almost certain that the cams were marked during mfg, not assembly.

Then the question becomes how precisely were these marks oriented relative to the cam lobes.

THE OTHER OPINION:
I have trouble believing that any machine shop would be as imprecise as has been alleged in applying these markings, and at the same time consistently grind the lobes with the proper profile & properly oriented relative to the other lobes.

The 3x8 series WSMs are quite clear that the cam marks are to be lined up. Nowhere in them is there mention of degreeing the cams in.

I've got a local factory trained Ferrari tech who was the lead tech at the NE dealership from '87 thru '84 or so. He was trained by FNA to line up the cam marks when changing belts.

I setup my car with the cam marks spot on, & dynoed higher than any other 308 when we had a dyno day at KTR last year.

Setting cam timing using a dial indicator, etc. is a painstaking process. When done right, there's no doubt about what you've got.

However, unless you're really good at it, it's very easy to be off several degrees & not realize it.

To answer your initial question. Yes, your marks are off relative to the cam caps, and some are off quite a few degrees.

Whichever method you choose to time your cams, you must pull the pins & rotate the cams relative to the cam gears until the marks are lined up, and you have a pair of holes that let the pins slip in. Very likely you'll have to pull 1 or both belts off more than once to achieve this.

 

Sorry martin, what brian says is correct. the factory does not stamp the cam at point of adjustment and they are only a guide to INSTALL the cams to get you very close to your mark.

The only mark that is accurate in those photos is the flywheel mark. the cam marks are stamped during the cam manufacturing process.

The Ferrari workshop manual shows a way to easily adjust the cam timing that will give you a good result.

best regards, Jim - ex-ferrari employee

P.S. If you look on the back of the cams when installed (not the pulley side) you will see stamped marks between the cam and the cap flange. this is the mark made by the factory after they did the cam timing. the mark will be on all cams except the distributor drive.

 

We've been through this before.

On the older models (1970's, 308 etc) Ferrari say to check the timing with exactly 0.50mm valve clearance. But if your actual clearance is 48 or 52 (or worse), or if your camshafts have ANY WEAR AT ALL your timing test will not be performed correctly.

So, if you plot a valve timing chart, and calculate the point of maximum opening which is halfway through the duration and NOT rely on open and close points, you will get a much more repeatable accurate test. This assumes a symmetrical cam opening/closing profile. I have tested many cams and they all are symmetrical, in my experience. I have found all 308/365/400/BB/Daytona cams I've degreed using this method to be within the (admittedly quite wide) goal posts.

This year already, I've rebuilt 3 of the 4 360C engines I have been commissioned to do. 360 are timed using an amount of lift at TDC on transition (as they have no valve clearance). The inlet cam is timed using the offset compound angle lateral valves. So far, I have found every camshaft to be within the "goal posts". Many absolutley perfectly, most well inside, and just one or two on the edge, but all within.

I also have found a couple of the assembly hand made marks to be slightly out, and I know how tricky it is to test on 360, so put this down to human error.

On the 360, the tappet is so small that true vertical access of the DTI (for accurate lift readings) is near impossible, so I have made a special tool for this. As the engine is rotated it is VERY easy for the DTI point to skid, get flicked or touched by the cam, rendering the test useless.

Typically, it takes me half a day to install and dial cams in... on the bench during assembly.

I have also found some 355's to be wildly incorrectly timed. It appears as though they have been timed using the central inlet valve, and not the lateral one, which puts the 5-8 bank a long way out. But these have all been serviced cars, and not factory built. Once retimed, the reference marks move back to the "goal posts", and the engine regains its lost sparkle.

The other, often overlooked aspect of cam degreeing, is establishing true TDC. The flywheel mark is no more accurate then the cam marks on 308 etc, but on 348 and on, there is no TDC mark at all, and the interpretation of this is critical.... another window for human error.

 

I had to pull both sets of belts off at least twice and I believe three times before we got to the point where the cam and cam journal marks are spot on. I may seem like a royal PITA and may cost you and extra 3-4 hours of time, but trust me, the payoff is well worth it.

 

As to your first statement, I guess you haven't been around Ferrari very long. Consistant inconsistancy is what they are famous for.

Second. There you go again putting too much faith in one of Ferrari's infamously incomplete and inaccurate shop manuals.

While it is true that the 2 valve motors do not breath well enough for small timing inconsistancies to be of great importance, they did go to the trouble to put valve timing marks on the flywheels and provided all stores with the factory degreewheels so we could do it right, and we were trained and expected to use them. Also in their constant effort to improve the technical material as well as make it more complete, by the 4 valve era it was in fact in the manuals.

Your local factory trained guy was trained by the same people as I and either he was sleeping or he is intellectually lazy because that is NOT what he was taught. But why believe me? I'm just another flake on the internet with a key board. You live in New England. You're right in the back yard of the most knowledgeable Ferrari guy on the continent. Ken McKay, President of Lamborghini Technical Services, former head technical Guru for Ferrari North America as well as their technical instructor for the period from the beginning of FNA through about the mid nineties and founder of Boston Sports Car. I think he still has his office there. Call him, at least he has some bonofides. And tell him Brian Crall and Dave Helms said hello.


It is true you can adjust the cam timing with the poor inaccurate marks by eye. You can also set ignition timing and fuel injection by ear and WALA the car will run, it might even run well. That does not mean it is the correct way and we do no one a good service by coming here and preaching it as gospel.

 

. You live in New England. You're right in the back yard of the most knowledgeable Ferrari guy on the continent. Ken McKay, President of Lamborghini Technical Services, former head technical Guru for Ferrari North America as well as their technical instructor for the period from the beginning of FNA through about the mid nineties and founder of Boston Sports Car. I think he still has his office there. Call him, at least he has some bonofides. And tell him Brian Crall and Dave Helms said hello.

QUOTE]

Amen. Probably the best tech rep. that I have ever met. He taught me a lot.

 

Guys~

As per the factory 308 GT4 service manual, on page B32, you will observe:

Place the cams on the reference marks, install the belt stetchers (tensioners) "check the valve timing with " (graduated flywheel) ".

Checking valve timing can only be done with a degree wheel, and that is also a "graduated flywheel". Guys, those marks are only for reference, not for actually timing the engine.

 

It is true you can adjust the cam timing with the poor inaccurate marks by eye. You can also set ignition timing and fuel injection by ear and WALA the car will run, it might even run well. That does not mean it is the correct way and we do no one a good service by coming here and preaching it as gospel.[/QUOTE]

Rifledriver, I guess the french lessons in the factory program weren't that great as it's actually "voila" rather than "wala."

Just kidding you - I think you have the right answer here based upon a much higher level of training than most here. However, everyone's entitled to an opinion, and, just like a belly button, everyones got one.

 

I've never claimed otherwise, 6 years working on 3082 isn't a long time compared to the experience you & the other professionals who post here bring to the forum.

I have put a lot of effort into learning as much as possible from as many sources as possible.

I'm well aware of Ferrari's many inconsistencies. However, my point was that machinists are into precsion, it's their career to be spot on. However, maybe the cams aren't made by machinists, just machine operators, which would explain imprecision.

Early yesterday AM I called Dave Castelhano, Ferrari service manager of KTR Motorsports & had a long chat with him. Dave is a long time FNA trained mechanic. They were trained to use degree wheels when they were available, & the marks & the special 2V tool for checking the cam gear marks as a fall-back.

He also said that you get what you pay for. The shops that offer lower cost major services do so because they just use the marks to cut several hours out of the job.

MEA CULPA:
Thank you for pointing this out! I really blew it here:

I actually did go back & read my 308 GT4 & QV/328 WSMs to refresh my memory before posting that, as I do before I do any major service.

Prior to that post, and for the last several majors I've done, I've mistakenly stopped reading the QV manual (See pics) at the bottom of page B41 where it says to lock down the belt stretchers & check the marks after rotating the engine twice. Somewhere I got it into my head that it was the end of the procedure(DUH).

Went back & reread the procedure again after reading your post because I didn't remember any mention of dialing the cams in, & was surprised to find that the procedure continued onto page B42. :{

Pg B42 starts with 'when it is possible, use a goniometer' implying it's desirable but not mandatory. I didn't have one at the time, & the only goniometers I could find were ones for torqueing fasteners & medical usages.

However, I'm beginning to suspect that 'goniometer' is another name for a 'degree wheel'. Is this the case?


After reading pg B42, I remembere reading it 5 years ago when I did the first major on my car. But have been overlooking it since.

Thanks, He'll be a great resource!.
I'll make it a point to meet/talk to him, & I'll say HI for you.
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Rifledriver, Ferrarfixer, Dr. ferrari,

Being some of the few professional mechanics on this site- I was wondering if you could quickly describe your process of timing belt removal/installation on a 3X8?
If you have in an earlier post- I apologize. I did a search and could not find anything specific.

Do all of you actually install degree wheels (where?), measure cam lobe durations , use dial indicators for TDC, etc? In that case, wouldn't all timing marks on the engine be useless? I'm sure everyone here would learn alot from your processes. I know I certainly would.

Information from the people who do this for a living is one of the most valuable assets of this tech forum.

thank you in advance-
jwise

 

I have been searching for a basic DIY step by simple step for belt change and vavle adjustment and valve timing tutorial..found lots of stuff but often confusing at some point. I also serached some info at velocepress.com but often found it incomplete and the WSM is also icomplete and assumes much technical background and special tools. I was thinking of doing the belt change and timing and feel it is doable...so I agree with jwise in searching for the thread that has the most accurate tutotial. thnx.

 

I'll let Dave H answer. It's about time he did something useful.