Degreeing cams

FBB,

What Exactly Is the 'Ferrari Way.'

Reading the WSM it comes across to me as pure Klingon Jibberish.

I'm Just DUMB ... I Guess.

 

Set the # intake and exhaust valve to 1/2mm. Slowly turn motor to intake opening mark on flywheel. With a pocket screw driver or similar device put a small amount of rotating pressure on the notch in the top edge of the cam follower and just when it stops spinning free you should be at the timing mark. On the exhaust side it should go from locked in place to free to spin. Then you are done.

 

Brian,

Good to read your input again.


That is exactly how I did it to find a reading on the degreewheel of when a cam/valve event occurred.

Now, how to adjust that event back into WSM Spec using the 'Ferrari Way' is where I got TOTALLY LOST.

 

Not surprising. Very poor explanation. Just keep trying different combinations until it works. After a while you get the hang of it.

 

I think if the WSM had less detail it would be clearer. For example, for the 308QV and 328 if it simply said "with the lash set to 0.5mm the intake opens at X degrees BTDC and the exhaust closes at Y degrees ATDC" that's all you need. It should be obvious that you need to approach these angles in the direction of normal rotation. For the 355, with hydraulic tappets, it is simply a specification of the relative lift at TDC for the intake and exhaust during overlap.

Now, back to something really boring, the F1 of the USA.

 

They are usually quite a bit clearer if you read the Italian. The translations are not done by technical people. In fact a lot of the translating is done by students in ESL, German SL and French SL type schools. All I can say is they are better than the early Japanese car manuals. One of those I read once describe the importance of maintaining tire pressures by saying "To avoid the dreaded skid monster....."

 

The V12s for the 456M, 550, and 575 have scribe marks from the factory cam timing on the backs of the cams. These were put on the cams when timed at the factory and before the engine was installed, so relatively easy to do. The only way to see them after installation is with a mirror, but they do make another check on cam timing. Mine (575M) were all spot on after degreeing the cams, but you do not really know that until the cams are degreed. You might have a Monday or Friday set of scribe marks. Much easier to get precision results with a large degree wheel. After the scribe marks are confirmed, I guess you could use them to confirm lock and swaps and they could be used as a first reference if you were brave.

 

You cracked me up Brian. I can just imagine some Honda engineer telling their F1 driver to "... avoid the dreaded skid monster....."

 

Well one of those ESL people translated "Overlap" to "at the crossing". I had to sit down and think about that for a while. Maybe a direct translation in a Latin based language. I have always described it exactly as you "Lift at overlap".

 

Well, that is why I wrote the Spread Sheet, using WSM Data, so one can 'nail it' (timing) within the inherent accuracy of the timing physics, math and system parts, 'first time, every time.'

I spent days 'fiddling' on the car, trying to time it and getting nowhere. Fustration sometimes hit highs I had to walk away from the car for months to calm down.

I'll never do this (valve timing) often enough to obtain 'the Knack' you and the other PROs obtain thru shear repetition.

So about 80-90 hours worth of work later and the automated EXCEL Timing Spreadsheet was born in BETA.

 

Only for a brief period did Ferrari not drill the entire circumference of the pulley and cam flange. The 308, 3.2 cars, BB and TR's. All the others you just picked the 2 holes that line up and you are done.

 

YEP. I can and do believe that 100%.

But with the 5-Hole Pullies and 3-Hole Cams, no such 'Luxury' option exists.

Depending on the number of degrees 'out,' with the 3&5 Hole System, you have to figure out which hole in the cam, which hole in the pully and how many belt-teeth clock or counter-clockwise to rotationally 'off-set' the pinned cam/pully as a fixed unit to properly time the cams.

With the mathimatical/physical system Ferrari employed, you can always get a cam to ZERO or at the very Worst, the +/-1 Degree WSM tolerance.

To then get it even closer as we all desire, than +/- 1°, there are other methods outside of the scope of the WSM one can employ, I know you are very well acquainted with.

 

We can argue the obsession with degreeing cams at every belt change to assure that they are within the WSM tolerance, or better, endlessly. I've been doing it for many years. My point has always been that, for a street car it's totally unnecessary to do anything but a lock and swap. Figure, you have been driving your car for 3, 5, 7, 10 years, maybe more. Now you are doing a belt change and all of a sudden you are worrying about a degree of cam timing? And then you have threads like this which propose to provide guidance in preforming the task, but which ultimately cause confusion and due errors right from page 1. If you followed the procedure as written on page 1 you won't even find true TDC let alone have your cams timed to anything near spec. Fortunately, several other posters recognized these errors and chimed in to correct them. But what is left is 13 pages and counting of misleading and confusing information.

One thing I found particularly amusing was that the OP claimed he measure the intake cam opening at 28* and closing at 106*, twice the Ferrari spec of 14 and 53. And he justifies this as " What’'s wrong? Nothing! Ferrari must be giving their specs in camshaft degrees which are ½ crank degrees", (post #12).
As John McEnroe would say, Image Unavailable, Please Login "you can not be serious!"

A little common sense: this implies that the duration of 247 degrees would also be at the cam, thus 494 crank degrees. Meaning at the crank the intake would open 28* BTDC , remain open for the intake stroke, still remain open for the entire compression stroke, and then close at 106 degrees into the power stroke.

It would be nice to have a accurate, concise write up on degreeing cams, but thread isn't it. And it is the poster child, IMO for what is wrong with Ferrari Chat. While the site is monitored, it is not monitored for technical content. Thus threads which are misleading, confusing, in accurate, or just plain wrong are allowed to perpetuate on the site, scattered among the threads that are truly useful.

 

Nobody is saying you should degree the cams for every belt change. After it is done correctly once, lock and swaps are fine. Some Ferraris are more sensitive to cam timing than others, too, so that needs to factor into what you do.

 

Actually Terry, that is exactly what some (including the OP) have been advocating over in the 355 section at least since I bought my 355 back is 2013. As I said, I've been arguing is for years.

 

John,

By quoting me I am assuming you've directed this narrative AT ME.

I thought we cleared this up in another forum/thread that 'NO,' I didnt advocate degreeing the cams at EVERY Belt Change. I DID at your FIRST DIY Belt Change. That way YOU KNOW. I also believe I offered up I would go at least 2 belt changes before doing so again, unless something caused me to 'pop' the valve covers earlier. 'POP THE COVERS, CHECK THE TIMING.

I thought that was put to rest. Perhaps I am wrong? I HOPE NOT.


'CLOSE ENOUGH FOR GOVERNMENT WORK.'

I Worked for the Govt for 33 years ... and I NEVER ONCE used THAT phrase EXCEPT as a PUT-DOWN Directed AT some lazy ...

I am a PERFECTIONIST. A True A-Whole in The Art. It helped in making me one of the BEST in the World with a rifle. At one time or another, I have beaten in competition, EVERY living Olympic and World Championship GOLD Medalist who still competed up to that time (1988). Execution to PERFECTION is the ONLY WAY you 'Get There.'

In EVERYTHING I DO, I endeavour to do the VERY BEST my then current knowledge, abilities and tools available will allow me to do. I Know NO OTHER WAY. And 'YES,' it is often painful to me and others around me. AND, I. DON'T. CARE.

With that preface into a large part of my psyche, lets talk cam timing.

You are VERY CORRECT that talking 'Degrees' and 'Cams' and 'Cranks' in the same breath can get Confusing and DAMN Quick. I admit I was in and out of that very confusion for 2 Solid YEARS.

What I finally did (slow learner; severely miswired brain), was start taking copious notes on EVERYTHING I tried, looking for correlations among my MANY False Results. As I FINALLY STOPPED Reading Words and STARTED Drawing Pictures, I finally had My EUREKA Moment.


How I 'Got There.'

'DEGREES' of a Circle are the same regardless of the diameters of the circles. They all have 360°. Where things 'Go All to Hell,' (get Confused Quick) is when one links(belts) two circles together of Different Diameters. And then rotates them. When this occurs, the Degrees of Movement of one <> the Degrees of Movement of the other as you point out above. And no one EVER makes which they are talkin about CRYSTAL CLEAR. ASSUMPTIONS ABOUND. I believe this is the nexus of the confusion of this topic


The Camshaft (3-Hole, 28° Pitch), Pully (5-Hole, 25° Pitch) and Belt (Tooth to Tooth, 12° Pitch) all have a series of mathimatical relationships with each other. To add to the fun, those items TOGETHER have a mathimatical relationship to the Crankshaft that is NOT 1 to 1 but 2 to 1. (Reader: NEVER FORGET That).

Steve Magnusson (member here) 'pulled' the BASIC raw data from the WSM of those relationships, crunched the math and put the results into a very easy to use matrix that went lightyears into explaining those very specific relationships. Ferrari really didn't Give-A-S**T to even try in the WSM.

He showed that the cams can be adjusted in a range of -6 to 0 to +6 Degrees* in increments of 1°, to bring a cam/valve event to (near) Perfect time IAW the WSM. The WSM; however, allows a max variance of 'Acceptable' of -1 to 0 to +1 Degrees.* Sounds good ... so far, right?

IF 'Close Enough For Govt Work,' is acceptable, the system is fine as it ONLY WORKS IN FULL Degrees (False) ... or is it HALF DEGREES (False) ... OR is it BOTH AT THE SAME TIME (TRUE).**

After using Steve's matrix, derived from the WSM, for two years and getting FALSE RESULTS on actual timing efforts on my car time after hundreds of times (literally), I stopped READING and taking notes and Started DRAWING my results ... EUREKA!!!


I DISCOVERED:

1) Although it should have been obvious, 2° of Crank Movement <> 2° of Cam Movement but 1°.

2) NO One made it clear to this DUMB-ASS (ME), that in the Ferrari WSM or in Steve's matrix*** what the word 'DEGREE' Meant; Crank or Cam? I read 'Crank' as 'Crank Degrees' is what the WSM infers and begins its Cam Event description with, 'XX° Before/After TDC."

3) An Engineer's World is ASS-BACKWARD compared to a 'normal' HS Grad's the world over. Work/Career Protection I suppose. In their world LEFT of a Vertical ZERO is PLUS, Right of a Vertical ZERO is MINUS. WTF?!?!?!?

Those THREE missing definitions caused me two years of 'wasted' effort.****

Once I SAW the situation as it was, with FULL Understanding as to the Terms and their ACTUAL Definitions, it was easy to THEN grasp.

I can get to 'Perfect' Cam timing of ZERO or 'Close Enough for Govt Work,' with a Cam KNOWINGLY and Observably OUT.

As detailed above, I. CAN'T. ACCEPT. THAT.

If I can see error, I MUST TRY to 'Fix It.


I Respectfully ask you to allow me my 'Indulgences' as I allow you yours.

V/R,

Mark


* - Cam or Crank Degrees? I Still Don't KNOW.

** - YEP. Which POV are you seeking TO and FROM?

*** - NO Slam against Steve. His matrix was written to show it could be done, NOT as a 'How To.'

**** - Like Edison and the light bulb, I learned 1000 ways How NOT To Time a Ferrari.

 

You are probably correct.

Just trying to explain my confusion, POV and where it all came from.


I'll shut-up now.

 

Mark, I was referencing the obsession with achieving, or rather maintaining better that 1 degree accuracy. It was not particularly directed towards you.

 

Destroying this thread? Shall I list the errors on page one?

 

What I said was that I choose to have a shop do majors because I don't care to spend the time on the 308 and I don't have the tools (a lift) to drop the engine in my 355. The majority of other services I do myself. Never the less, what I choose to do or have done has nothing to do with my knowledge base and ability, or 55+ years experience, or 35 years of Ferrari ownership.

It's fine that you promote. It's not fine that you write a thread that is misleading and inaccurate. 12 years old or not, it was not a good start. Yes, I give you credit for evolving. But even now, statement like "I time my car at each belt change because it's easy" are just condescending nonsense.

Why not do it? Because it isn't necessary.

But since you want to fault, I'll go ahead a summarize several errors that you made when you started your thread. And why, frankly, it would serve the community well to delete the thread.

1) Finding TDC. While there is nothing basically wrong with the concept you used on page 1. The error is simply that in your discussion state that you approach your reference position by rotating in the same (CW) direction on both sides of TDC. "Crank the motor CW so the dial guage reads .050” ...... Crank the motor CCW so the dial guage reads say .090 the other way. You need to overshoot in the CCW direction because you need to take up the timing slack. Now crank CW to .050 again. " This guarantees your result for TDC will be in error. This is the result of the stacking up of tolerances and clearances being different when the piston is being push up the bore and pulled down the bore. This stacking up results in, as you know, what is called the dwell. That is, with the piston at TDC the crank can be rotated slightly past TDC without the piston moving in the bore. The angle of rotation being dependent on the exact amount of the difference in how these clearances stack up. It may not be significant in your mind, but it's real and it leads to inaccuracy. FWIW, here is a plot of how far the crank of a 355 must rotate from TDC vs the amount of this "slack" in the piston movement. Even as little as 0.0001" requires almost 0.6 degrees rotation.
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The point is not about how much the error is, but that it introduces an error which is unknown. Other posters pointed this out later in the thread.

2) Then look at you statement that I previously referenced where you suggest that Ferrari specs are for cam angle, not crank angle to justify your finding of your intake opening at 28 and closing at 106 as opposed to the Ferrari spec, 14/53. I mean seriously, where is the common sense? If the intake DID close at 106 degrees ABTC it would mean that the piston was 64% of the way up the bore on the compression stroke. That isn't going to produce much power. But for the sake of argument let's assume for the moment that those angles were correct. 28 + 180 + 106 yields 314 degrees for duration in crank degrees. But wait. That is neither the 247 specified by Ferrari nor twice that, 494 degrees which would be the duration at the crank IF the Ferrari spec were in cam degrees. But what boggles the mind is, how did you get such wrong numbers to start with? And you are questioning my knowledge and ability? Rather than recognizing that your result didn't make sense you attempted to explain it away.

3) Moving right along, you then wax on about the Ferrari spec of setting the lash to 0.5mm (0.02") on solid tappet cars for setting timing. And ultimately state, " Still I have questions because my numbers were perfect and my exhaust clearance is set to .035” not .020. So when Ferrari also quotes .020 I have no idea what they mean. " So, you got perfect results with the wrong valve lash, admit you had no idea what Ferrari meant, and you dare to tell me I have no clue?

4) Next you turn to the lobe centerline method. Magically you find that the peak lift occurs at 109.5 degrees ATDC, crank angle. Again, where is the common sense. For this to be the case the Ferrari spec must be in crank degrees, not cam degrees. So you have contradicted you previous assertion that Ferrari spec are for cam angles.

I appreciate that you were trying to provide some guidance to help other degree there engines, but you, perhaps, should have written a complete document on the matter, read it over several time, though about it, given it to someone to review, and maybe you would have caught some of these errors and contradiction before you cluttered Ferrari Chat with this incorrect and misleading information.

As for cam timing or not, I have not criticized anyone for time cam at every belt change. What I have done and demonstrated is that it is unnecessary. I will reiterate my position. It's very simple. You car has been running fine for 3, 5, 7, 10 years or more and you then decide it's time for a belt change. Due to a number of factors, all associated with the old belts: wear, change in elasticity, stretch,... the timing will not be what it was when the belts were new. Simply swapping the belts will restore the timing to what it was to within less than 1 degree. That is, when you swap the belts the timing will be closer to spec that it was with the old, warn, stretched belts. If that's not acceptable, or you believe that the timing is off for other reasons, go ahead and retime the cams. But to simply say it's easy and to imply that the cam covers are already off the car isn't necessarily the case. For a 308 cam cover don't just come off. I discussed that in another thread. And suppose you examine the engine and there are no leaking seals or gaskets. You may not want to pull the cam covers. If we are talking about degreeing cams are we just talking about a 348 or 355? Or are we addressing all Ferraris with belt driven cams, V8 and V12? You dismiss things to bolster your position at the expensive of being inclusive.

And please don't try to take credit for the work DaveRocks has done in the refinishing business. Dave is not a DYIer. He is a professional business owner who saw an opportunity and exploited it. I was along for much of the ride and can bare witness to the extent Dave researched the cleaning, preparing and refinishing procedure. I often though he was nuts. And when he dumped a large chunk of money into a custom designed spray booth I was sure he was nuts. But he grew the business into the premier refinishing business in the world today. Hardly a DIY opt.

Now, I will say that I do believe that in the 12 years since 2007 you have recognized that much of what you posted then was in error. I'll give you credit for that. But I will simply point out that in 2007 I was 22 years into Ferrari ownership and well versed in what the WSM said about cam timing and found it quite understandable, see my post #305 above.

 

Starting to seem like you two see things differently.

 

Wow, I have been following this since June when it was resurrected. I have performed cam degree procedure on hundreds of engines. I built race engines for many years. I find it interesting just reading the back and forth. Thanks for the read.