| Author | Message | ||
| James J. McGee (Dr_ferrari)
Junior Member Username: Dr_ferrari Post Number: 169 Registered: 7-2002 |
Very true phil....But, I would think if you pay peanuts, you would more likely end up with Elephants..  either way wouldn`t want them in my shop... Best regards, Jim | ||
| Phil Hughes (Ferrarifixer)
Junior Member Username: Ferrarifixer Post Number: 122 Registered: 7-2003 |
And Doc, as for staff, My theory there is....if you pay peanuts, you get monkeys. And if you employ monkeys....prepare to trip on a few banana skins. I've found, through experience on both sides, that trust is a mutually beneficial contract with high returns....just pick your contractee carefully! | ||
| Phil Hughes (Ferrarifixer)
Junior Member Username: Ferrarifixer Post Number: 121 Registered: 7-2003 |
You're on the money Jeff. My theory is that any toothed belt should not be stretched as such, but have all it's slack taken up when new. When old, it should be allowed to have a little slack. Of course the very grey area is how much?????? That's where only experience can help you...... | ||
| Russ Turner (Snj5)
Member Username: Snj5 Post Number: 421 Registered: 2-2003 |
Interossiter!! One of my fav movie references!! | ||
| James J. McGee (Dr_ferrari)
Junior Member Username: Dr_ferrari Post Number: 167 Registered: 7-2002 |
I have heard so many trick ways to check belt tension, I could write a book. Maybe I ought to make a tool too and sell it to the dealer network huh? and jeff, you got it...An experienced tech knows how to properly tension a belt and what belt tension is proper. so your way ahead of the game. Phil, Tough thing to remove bad habits from new recruits. I think I would rather have a real green technician fresh out of school, Much easier to fill the head full of crap..(they suck it up like a sponge) Best regards, Jim | ||
| JRV (Jrvall)
Intermediate Member Username: Jrvall Post Number: 2293 Registered: 11-2002 |
>>saying how they all use the squillion dollar interossiter powered flux capacitor reverberation tool to check cam belt tension....<< I hope you told him..."ohhhh yeaaaa we have 3 of those we use, the second and third are to check the accuracy of the first one...hehehe!!! { } | ||
| Jeff Green (Carguy)
Member Username: Carguy Post Number: 471 Registered: 10-2002 |
ROTFLMAO.....!!!!! Thanks Phil....I need a good laugh today! Yep, that belt tension thing is a "black art" as they say. Working on my car, I see that the spring inside the tensioner is preset at the factory for a specific load (however many kilograms it is?) So in my opinion, setting the initial belt tension is a piece of cake. It'a afterwards, down the road (pun intended) that it's only real experiences and wisdom that tell the mechanic if the tension is good. Good Luck with that new man. | ||
| Phil Hughes (Ferrarifixer)
Junior Member Username: Ferrarifixer Post Number: 115 Registered: 7-2003 |
JRV I just interviewed a guy from the local dealer who may come to work for me. He's a great guy with excellent background and experience......then he started saying how they all use the squillion dollar interossiter powered flux capacitor reverberation tool to check cam belt tension....and I thought NOOOOOOOOO,,, I must save this man from the brainwashing propaganda dealers pump into their employees' brains.. He starts Monday. Then I can fill him full of my own crap! | ||
| JRV (Jrvall)
Intermediate Member Username: Jrvall Post Number: 2282 Registered: 11-2002 |
>> Please understand my pain being an American/irish technician on the Factory payroll. I know and have seen and have felt all the politics that goes along with being in that position<< I knew there was something about you I liked...you're an UNDERDOG...hahaha!!! The germans try to pull the same nationalist BS... This is why occasionaly I like to point out their failings to them ...just for a reality check and to remind them that the porch has Big Dogs on it from all countries and some of those Big Dogs don't buy into crap..{ } Don't miscontrue..the party line is fine sometimes...but only to a point...then it's only reality that matters...{ } In my case I study the craft, not the religion...and I'm careful who I pick as my hero's. Regards, JRV | ||
| Tom Bakowsky (Tbakowsky)
Member Username: Tbakowsky Post Number: 547 Registered: 9-2002 |
Bill...I agree 100% with you on that for sure. Obviously there is know way of telling if a car has been properly taken care of untill you start to pull things apart. A car can appear nice on the outside but be a time bomb on the inside. Mostly I was just getting to the fact that there are to many variables to be concerend with when setting timing. No belt or chain driven engine will ever be able to be timed excatly. There are just to many things moving and streching to achive perfect timing. Factory marks are inplace and I beleive they are put in the positions they are for that speicific reason. If your were to try and time the engine to "thightly" then with strech, defection, tensioner bearing movment, or any other vairiable that could crop up, then you are that much closer to causing serious problems. The engineers I beleive factor all this in when the design an engine for street use. They understand that people will not get their service done right when the manuel calls for it. They might go and extra 20,000 miles before they even consider it. The engine must be alowed a certain forgivness for this. I beleive that is why the marks are put were they are. | ||
| Bill Sebestyen (Bill308)
Member Username: Bill308 Post Number: 507 Registered: 5-2001 |
Tom, In my case I bought the car with an unknown history and some obvious issues. Faced with a lot of unknowns, especially on some of the older cars, I think you have to establish some baselines and begin to eliminate these unknowns. One doesn't always know who worked on what. Flywheels get changed, cams get changed, parts get mixed up, left out, incorrectly replaced. If you know the history and the car is running good, you might be able to take some short cuts. But sometimes, it's a good idea to go back to basics and confirm things. | ||
| Tom Bakowsky (Tbakowsky)
Member Username: Tbakowsky Post Number: 546 Registered: 9-2002 |
Why if the cam marks are so far out to lunch from the factory, do the cars seem to pass emissions when they are a couple of years old with the original belts? If the cars were that finikey to time, why wouldn't Ferrari have an entire procedure printed for their techs to correctly set the timing using dial gauges and degree wheels. Porsche does not even have timing marks. You have to set them up using gauges and degrees. You would think that since there is such a discrepency in the position of the marks they would not even bother to put marks there in the first place. I have done numerous first time belt services and on every singal one of them the cam marks line-up exactly to the marks on the cam cap. I ferrari themselves set the engines up this way, and the cars pass emissions when leaving the factory, then why are you guys fighting over somthing so minimal? | ||
| James J. McGee (Dr_ferrari)
Junior Member Username: Dr_ferrari Post Number: 166 Registered: 7-2002 |
Good for you jeff, You will do just fine I`m sure. I look forward to the pics, Good luck and regards, jim | ||
| Jeff Green (Carguy)
Member Username: Carguy Post Number: 467 Registered: 10-2002 |
There sure is a lot of brain power here on fchat! I can't THANK ALL OF YOU enough for sharing your experiences and advice. To anyone else out there who is NOT a mechanic and contemplating doing this procedure....get ready mentally prior to doing anything. I have read, re-read, and re-re-read the shop manual. And after going through this thread numerous times, I believe I'm ready to work on my engine. The feeling of intimidation is gone now, replaced with one of purpose and curiosity. It's easy to make the procedure out to be too difficult to do, but it really isn't. But as pointed out by true authorities here, the potential human error is very real. This is the biggest danger in my opinion. I will take great pains to ensure this doesn't happen to me. Each step completed and verified prior to going on to the next step. I'm actually a bit excited about it. I'll try and take some pics, and start a new thread of the procedure. AGAIN, THANK YOU fellow fchatters for your help and support! | ||
| Bill Sebestyen (Bill308)
Member Username: Bill308 Post Number: 506 Registered: 5-2001 |
Jeff, I don't know if the cams are symetrical. Maybe someone else does. Assuming the cams are symetrical and the cam timing in your post is correct, your 106 degree point of maximum lift is correct. Also your hypothesis that you can split the difference if the checking difference isn't perfect is also correct provided you have at least 0.050 shim clearance to begin with. Clearances smaller than 0.050 probably should be avoided as you start to encroach upon the initial ramp which is less precise. I believe the 0.050 clearance specification is only important if you are trying to duplicate the factory timing numbers. If all the engine geometry is perfect, the measurement is perfect, and the workshop manual valve opening and closing points are correct, the the 0.050 clearance should get you to the correct valve opening and closing values. The basis for all timing functions is ensuring that the TDC mark on the flywheel is accurate. I'd recommend you confirm this prior to moving on to check other timing functions. When I did this for my car, I had the cams off and checked TDC by approaching TDC with the crank angle about 90 degrees from TDC, from both directiions, with grat care. This crank angle will give you very good resolution for finding TDC. With a degree wheel and pointer fitted and a dial indicator in the number 1 spark plug hole, I was able to split the difference and confirm the TDC mark on my flywheel was within one quarter of a degree of my degree wheel measurement. From that point on I assumed the flywheel mark was accurate and had good confidence that dependent measurements would be accurate. | ||
| James J. McGee (Dr_ferrari)
Junior Member Username: Dr_ferrari Post Number: 165 Registered: 7-2002 |
"all factory propaganda aside...line up the marks, then follow the WSM procedures "to check" for accuracy" Excellent advice for the DYI`er. could not agree more. AT least someone like jeff can verify and feel he has done a complete job. Personally If I see something I don`t like,I do check another valve just to be sure (4 valve engine gives you 2 verifications per cam). I think that as long as you are on specification based on the degree wheel all should be fine. Just as a last note, when the initial cam timing is done at the factory, the technician stakes a line at the back of each of the cams. It can be just another verification point for you to check after you are done. Phil, I didn`t mean for the Couple of degrees being disasterous" statement to be taken as a scare tactic. I think it`s great that these owners take the time they do to learn about these cars. I just want them to be aware that there should be other checks than the cam marks. 4 or more degrees to me equates to a couple, but when I perform this procedure I get spot on and the variables in the belt, possible .49 instead of .50 will not equate to much variance with the result. If I did not get spot on, those variables then could cause a problem. " disagree with the Factory rhetoric that only "employees" of Ferrari (and preferably only employees with Italian sur names) should be allowed to open Ferrari hoods. It has long been proven that intelligence & skill is given out by GOD, not Ferrari!!!" JRV, I agree so much on this point, Please understand my pain being an American/irish technician on the Factory payroll. I know and have seen and have felt all the politics that goes along with being in that position. and finally, congrats to the 550 prodrive, excellent job. although I do feel the 360 are still doing well concidering. That 550 is an excellent machine, have a pic of it as my wallpaper. Best regards, Jim | ||
| JRV (Jrvall)
Intermediate Member Username: Jrvall Post Number: 2260 Registered: 11-2002 |
So much for the factory boys...maybe they should hire some privateers if they want to run with the big dogs ! { } http://www.ferrarichat.com/discus/messages/14/306791.html?1061755618 | ||
| James Selevan (Jselevan)
Member Username: Jselevan Post Number: 726 Registered: 6-2002 |
There is a certain advantage to viewing a thread late in the discourse. While not as experienced as JRV, Phil, James M., I have rebuilt a number of 6- and 8-cylinder F-engines. I have timed the cams precisely as described in the WSM. Always passed emissions. What is interesting (to me) is the importance that some attribute to "exact" cam timing, that is, above and beyond that that is achieved by the factory cam mark and factory TDC or TDC by dial indicator through the spark plug hole. I cannot believe that Ferrari engineers would produce an engine that required better than +/- 1.5 degree cam timing. Think, for a moment, of the other variables that contribute to the "ideal" internal combustion process. 1. At what pressure does each of the 12 injectors begin to "spray"? 2. What is the fuel pressure going down each of the 12 lines to these injectors? 3. At what RPM are we referring to? This is important because the length of each exhaust manifold will influence the pressure pulses. 4) What is the compression on each piston crown, because this will influence the time required to open the injector and introduce its charge. I can go on and on. No doubt that cam timing is important, but +/- 1.5 degrees appears, at least from this discussion, to be within tolerance and anticipated by the designing engineer. The marks on the cam are there for a reason. If a degree wheel were necessary, the WSM would call for it. (Sorry if the WSM does call for it. I do not have mine in front of me). It seems that "perfect" has become the enemy of "good." Jim S. | ||
| Jeff Green (Carguy)
Member Username: Carguy Post Number: 465 Registered: 10-2002 |
I'm gonna toss out some ideas here, and welcome any constructive criticism. Question: Are the cam lobes symmetrical in shape? (I'm gonna physically check this out soon) If they are, then what about this idea. I can understand the potential error in establishing the 0.50mm clearance for timing the cams. So why not check the cams in a way that eliminates this variable. The spec.s show the intake opens 16 deg. before TDC, and closes 48 deg. after BDC. Theoretically the peak of the lobe should be acting on the valve at 106 deg. after TDC. So could I plot (degrees and travel)out the valve movement as it's being opened with an indicator? The opening and closing ramps should be "centered" or occur the same number of degrees away from 106 deg. after TDC correct? Is this the "fully open" method of verifying the timing? | ||
| JRV (Jrvall)
Intermediate Member Username: Jrvall Post Number: 2248 Registered: 11-2002 |
>>).....if you want to be really pedantic, you should measure every last cylinder (yes, all 12 on a Testarossa) , and I mean TDC position AND cam timing, and then make an AVERAGE of the readings found and set the cam to that!!!!!! << Agree that only measuring one cyliner on each bank is using huge amounts of Faith and making HUGE assumptions that the cams are exactly identical (which is doubtful). Not to mention the fact that Ferrari doesn't even supply shims in infinate sizes and gives a .004" go no go range even on their wide range of acceptability for valve lash, combined with the fact that the gears have a very limited adjustment span.. All this built in slop adds up to a sitution that close is good enough, cause it's all you're going to get (like it or not)!!. (And in James' defense close is pretty close) All the above close is good enough tolerances is why Factory Engines have to be redisgned and modified for all out racing. Much like the Holman & Moody Daytona Engine that won Daytona, giving the 365GTB4 it's nomeclature Daytona, or the Pro-Drive 550 Engine that won LeMans. Jeff, all factory propaganda aside...line up the marks, then follow the WSM procedures "to check" for accuracy. To the best of my knowledge the WSM does not contain errors in the cam timing section. However it takes an expert to recognize printing errors of which there are many. As I stated earlier, to use Ferraris manuels comfortably one should first posses the knowledge to write the book, in order to instantly recoginize the mistakes. I agree whole heartidly with James that setting cam timing on Ferraris is a job best left to experts...(experts know when what they are seeing is wrong and stop immediately until the "Hmmm this doesn't make sense" is solved). On the flip side a careful DIY'er can perform a service on his own engine without causing damage or problems. One is right to be worried if they are beginners trying to learn on 12 cylinder Ferrari Engines...no expert I know of started his carreer on 12's and worked his way down...the accepted method of learning is to start with the basics and move up as each new lesson is permanently imprinted. Having a data base built from the ground up insures each step goes smoothly. However...there are some very talented and conscientus DIY'ers that I know of out there and setting cam timing on a 12 is well within their ability to perform correctly. The key is being completely satisfied that each last step is correct before moving to the next step. I agree with James that it's easy to make mistakes and letting just anyone run amuck claiming Ferrari Level skills is risky and fool hardy. I agree with Phil that truly practical experience (the broader the better) is essential. I disagree with the Factory rhetoric that only "employees" of Ferrari (and preferably only employees with Italian sur names) should be allowed to open Ferrari hoods. It has long been proven that intelligence & skill is given out by GOD, not Ferrari!!! | ||
| Phil Hughes (Ferrarifixer)
Junior Member Username: Ferrarifixer Post Number: 98 Registered: 7-2003 |
The human error comes in all over..... Where is TDC EXACTLY there seems to be a long dwell period, how securely have I fitted my dial gauge, did I just knock the pointer, did the degree wheel slip from where I installed it, how quickly should I turn it, have I plotted my valve timing diagram properly to calculate the max open, should i get a second opinion, why is the RH bank different to the LH or did I just write it down wrong, did the cat come and jog my instruments while I had a cup of tea...... Jeff, use the force. Trust the marks, set them DEAD centre by eye after a couple of turns of crank, and then just bribe the emmissions tester if you get in trouble. You can give him the money you've saved by getting it done in a cost effective amount of man hours!!! (thats a joke guys) | ||
| Jeff Green (Carguy)
Member Username: Carguy Post Number: 464 Registered: 10-2002 |
The more I read this the more nervous I get. I did pull the cam covers off my TR yesterday to check the marks. With the engine at TDC, I'm somewhat relieved, cam marks dead center to the cap marks. I will get a degree wheel and verify just how close these marks really are this week sometime. I certainly agree with all about this procedure not being for beginners, of which I AM one. With all the criticism about the shop manual I'm a bit afraid to trust anything in there. Are the cam opening and closing spec.s correct at least? I will use the "full open" method as that makes the most sense to me....at this moment, who knows my view may change depending on the way this thread goes. JRV stated it's been his experience that when properly degreed the cam/cap marks are within a half a line of each other. James J. McGee stated that if someone lines up the factory marks and the car passes emissions he'll join you in times square. This is where I'm confused. If the factory marks phasing acuracy is within a half a mark width, but yet setting to these marks may not result in a proper running engine, about how many degrees off optimum can a half a line width be? I'm sorry if I beat this to death, but I'm learning lots from this thread. What are some of the human errors or pitfalls that you have seen or experienced regarding the timing of the cams? | ||
| Phil Hughes (Ferrarifixer)
Junior Member Username: Ferrarifixer Post Number: 97 Registered: 7-2003 |
Again no problem with what you say theoretically. I still, however say your "Couple of degrees being disastrous...." statement is a massive scare tactic. With any method of cam timing, it is universally common practise to only measure the cams on one cylinder per bank (usually the first firer).....if you want to be really pedantic, you should measure every last cylinder (yes, all 12 on a Testarossa) , and I mean TDC position AND cam timing, and then make an AVERAGE of the readings found and set the cam to that!!!!!! I'll bet your house for mine that all cylinders are not identical to 2 crank degrees. Then, you'll be busy for weeks adjusting it, but if you charge an hourly rate who cares eh!? I'll give you a get out clause and say that perhaps you are referring to the camshaft being a couple of degrees out...that equates to the crank value of 4 degrees error, which is an adjustable amount of discrepancy. There...deal??? LOVE these cars....!! | ||
| James J. McGee (Dr_ferrari)
Junior Member Username: Dr_ferrari Post Number: 164 Registered: 7-2002 |
"If a car had the cams mistimed by a couple of degrees, I'd imagine it may have to be revved slightly higher or lower to achieve similar emmissions ie approx 40-50rpm difference at a rough guess. " This is exactly my point. Just for instance, If the exhaust cams are retarded a few degrees too much, your HC reading can increase between 300 and 900 ppm at idle which in some states they require a reading done at idle and the car will fail the test. You are correct that bringing the idle up will clear the Hc reading but in these tests, they check idle as well and if too high, the vehicle will fail. The simple reason is the increase overlap of the cams. and at idle, and concidering that the ferrari converters are not the best, The cam timing has to be within the tolarances. "When I tune them, I usually can get them running perfectly at 0.7-0.9%CO and about 80-150 HCppm at 1000rpm, with no cats on a euro car. They start and run perfectly in all conditions when tuned to this spec with balanced plenums and quality fuel straight after a service. How would this equate to US emmission levels?? " I have done over 50 Testarossa services with the same results as you have reading before the converters using the shim method. and the cars perform well. Again, I`m not saying your method is incorrect, just a different procedure and honestly as long as the results are good, It really does not matter. And again my point is this procedure be it shim or max open, is a job best left for an experienced technician and not the DYI`er. Funny, I started with Ferrari the same year as you. I have man hours that I have no idea how many... 2 year degree in automotive technology and every factory school that ferrari ever offered. ASE certified master with L1 certification (emissions certification) and emission inpection licence for Pennsylviania and New Jersey). Beyond that I can say that I have seen every ferrari that came into the country from 1987 to 1998 making the final adjustments to at least 1/2 of them before they were delivered to the dealer, So when I say i`ve see it all, I have including poor cam adjustments from the factory. And my only other point is that you cannot use the cam indexing marks as a final timing mark. Ferrari propaganda or not, those marks are not accurate. not that they are stamped wrong, (which has happended)but that the diameter of the wheel (in this case the cam which is only about 24mm in diameter) is too small to be accurate. My fear is that our DYI`er out there will just set the crank to TDC and line up those cam marks and may not get the results they desire especially if they remove the pulleys and mess with the indexing pins to get that cam mark right on. "You've greatly underestimated the depth of mechanical understanding present on this board... And this is very reminisent of my early days at engineering school...Theory versus application" David, Not at all, I believe that guys like JRV and phil are well accomplished technicians and I respect their points. I know there are some out there with mechanical degrees and I don`t dispute that. Again, my fear is that as you have said: "setting up the cams on a multi-cam engine certainly isn't a job for a novice" and there are some out here that may be novices just trying to do this procedure on their engines and thinking it`s not that big a deal. And if I felt that mechanical understanding on the board was poor, I wouldn`t waste my time. I find some very intelligent conversations and enjoy reading them with occasionally joining in. Best regards, Jim | ||
| Phil Hughes (Ferrarifixer)
Junior Member Username: Ferrarifixer Post Number: 93 Registered: 7-2003 |
Doc I've not worked in America, so I'm not fully conversant with the test procedure. But I have done over 30 full major/belt/valve clearance jobs on Testarossa's in the UK. When I tune them, I usually can get them running perfectly at 0.7-0.9%CO and about 80-150 HCppm at 1000rpm, with no cats on a euro car. They start and run perfectly in all conditions when tuned to this spec with balanced plenums and quality fuel straight after a service. How would this equate to US emmission levels?? I'm not trying to undermine your perfectly correct theory, it's just your specific cause and effect details I query! If a car had the cams mistimed by a couple of degrees, I'd imagine it may have to be revved slightly higher or lower to achieve similar emmissions ie approx 40-50rpm difference at a rough guess. What is the test procedure??? Does it specify an exact rpm to test at??? Like you, I'm open to debate and can only go on my experience (approx 30,000 personal man hours of spanner work on ferrari since 1987, backed up with incalculable hours of workmates experiences, and 3 years tertiary diploma education in Motor vehicle engineering) | ||
| David Feinberg (Fastradio2)
Member Username: Fastradio2 Post Number: 290 Registered: 4-2002 |
So, Let me make sure that I understand this correctly... The best or proper way to set up the cams is to use a degree wheel...and the specified lift per the specified shim (valve lift). Hmmm, this procedure sure isn't unique to Ferrari! The marks on the cams and cam caps are "for assembly purposes only"...What the "that" mean? Why go through all that effort, then? So, the factory degrees the cams in at the time of assembly, and then puts arbitrary marks, more or less, where the correct timing should be? Degree wheel using "Ferrari WSM procedures" or other known to be accurate procedure, or sqinting at the marks on the cam caps...Either way, you're accuracy is limited to the resolution of the cam alignment holes....which I believe it 1.5 degrees. So what's the width of the cam timing marks scribed on the caps? Certainly less than 1.5 degrees... Yes, setting up the cams on a multi-cam engine certainly isn't a job for a novice, but a couple of thoughts come to mind. You've greatly underestimated the depth of mechanical understanding present on this board... And this is very reminisent of my early days at engineering school...Theory versus application. By design, the accuracy of the cam timing is limited to the adjustment resolution on the cam/cam sprockets...Degreeing the cams, by whatever methods choosen, does not circumvent that fact. | ||
| James J. McGee (Dr_ferrari)
Junior Member Username: Dr_ferrari Post Number: 163 Registered: 7-2002 |
"thoery is fine, but it's hands on that counts for the real world. " Huh?? I believe we are speaking of Real world FACTS. and the fact is the factory recommended procedure for the testarossa is the shim method. and it does work well. Now I`m not saying it`s the only way or the absolute best way to set cam timing, Just that it is the recommended procedure and it is accurate in the hands of a experienced technician. now if we are speaking of a 355 or 360, now thats a different story. "The 0.50mm clearance, degree wheel method adds so many potentials for human error that it is not a reliable meethod. " Yes you have a valid point and as I have said previously, This is a job most suited for a seasoned ferrari technician and IMHO not for the DIY`er as JRV stated due to the poor information from the WSM and inexperience. Plus I believe your thoughts of variation are somewhat exaggerated. Take note that the flywheels are marked by the factory for intake open and exhaust close for each bank just for this procedure. - another FACT. "Stand in front of a mirror and repeat "a coupe of degrees can have a disastrous effect on emmissions" I`ll tell you what, Take a 1989 Testarossa, you set cam timing by just putting the crank at TDC and squinting your eyes at those cam marks (on that 24mm diameter cam)and put them dead center as your trained eye can see, then take it to a California emmission test facility. If it passes, I`ll join you on times square. Best regards, Jim | ||
| JRV (Jrvall)
Intermediate Member Username: Jrvall Post Number: 2245 Registered: 11-2002 |
>>thoery is fine, but it's hands on that counts for the real world. << YEP !!!!! Phil, if we here about a unicycle riding juggling flasher anytime in the future we'll say a salute to you....{ }...lol. For the rest of you guys...repeat often until it's a reflex..."The Truth is Out There, I will not be brainwashed by factory propaganda & rhetoric....I will seek the truth my own good !!!! | ||
| Phil Hughes (Ferrarifixer)
Junior Member Username: Ferrarifixer Post Number: 86 Registered: 7-2003 |
Dr Ferrari Stand in front of a mirror and repeat "a coupe of degrees can have a disastrous effect on emmissions" 10 times. Keep doing it until you can say it without laughing. Then do it in front of an experienced Ferrari technician without them laughing at you. Then, I'll ride a unicycle naked through Time Square while juggling half peeled banana's singing christmas carols......and I'll still be making more sense than you........ Get a grip Doc, thoery is fine, but it's hands on that counts for the real world. The 0.50mm clearance, degree wheel method adds so many potentials for human error that it is not a reliable meethod. The TDC dwell interpretation, clearance inaccuracies, dynamic variances of belt length and fluctuation and human element is incalculable. | ||
| JRV (Jrvall)
Intermediate Member Username: Jrvall Post Number: 2244 Registered: 11-2002 |
>>and I believe a lot is lost in the translation for the inexperienced. <, right..and that's one of the points here...much of the audience and those we are trying to help along with their DIY'er programs can easily get into trouble trying to decipher a complicated WSM that assumes the reader has vast pre-experience before opening the pages. For guys like you or I the WSM generally tells everything needed and then some...in fact one has to be pretty up to speed to know what is being left out... It's impossible for me to argue about how many degrees out makes an engine run poorly because I make sure my work is spot on naturally...but I've seen plenty of cams out, and not really running poorly so much as just needing service. I agree with you completely that these DIY'ers should adhere closely to the Factory Procedures and Specs. BTW: That's funny about ECU placement, they do have an uncanny knack of finding places water collects to store computers { } | ||
| James J. McGee (Dr_ferrari)
Junior Member Username: Dr_ferrari Post Number: 162 Registered: 7-2002 |
we once suggested that ferrari install the engine ecu on the outside body of the car to keep the water from getting in. It seems wherever they mount the ecu, water finds it`s way there. They found no humor in that comment.... best regards, Jim | ||
| James J. McGee (Dr_ferrari)
Junior Member Username: Dr_ferrari Post Number: 161 Registered: 7-2002 |
<"yes I hear what you are saying, and to be dead certian one must degree the cams. However the novice may have a hard time if glitches occur because "THE FACTORY" forgot to write a REAL WSM...and with the cryptic crap they do produce there is not much info to lead the inexperienced along. " Very true - the manual is very "cryptic" and I believe a lot is lost in the translation for the inexperienced. My point is just that this job is not for the inexperienced and can easily be "botched up" if not done correctly. I also agree the Ferrari factory is far from perfect and has on occasion has made some poor designs (ie..348 removable tops for one) best regards... Jim | ||
| JRV (Jrvall)
Intermediate Member Username: Jrvall Post Number: 2243 Registered: 11-2002 |
>>I must say that Ferrari factory has stated to me that those cam marks are only for assembly purposes and not as a gauge for cam timing accuracy.<< Jim, I don't want to argue about what the factory says...was it ALL voices in concert or one long audio tape of every employee? I stopped hearing "propoganda around the time of Nam....from all sources. Also if the factory was so damn smart how do they explain all their own F--K Ups? and why are the convertible tops crap from hell, or why does Pro-Drive have to run Lemans without the factory even though the smoked the Factory 360's ass's???????? The cams may be indexed for assembly only but they are indexed on the Cam Making Machine to exacting degrees. Now the electrics is a different story, they are definately experemental only. That said.... yes I hear what you are saying, and to be dead certian one must degree the cams. However the novice may have a hard time if glitches occur because "THE FACTORY" forgot to write a REAL WSM...and with the cryptic crap they do produce there is not much info to lead the inexperienced along. { } | ||
| James J. McGee (Dr_ferrari)
Junior Member Username: Dr_ferrari Post Number: 159 Registered: 7-2002 |
QUOTE: <Like Phil, I have degreed cams on Ferrari engines as old as 1953 212's and have consistently over the last 25+ yrs seen the internal cam marks align with the cam cap index line within the range of the thickness of half the line itself....additionally I have seen so many mistimed cams to loose count that had absolutely NO appreciable telltale signs on running condition and would never have been known without the visual inspection.." The older carbureted ferraris had more tolerance for a cam being out of spec than the newer Electronic fuel injected cars. Newer ferraris like the Testarossa use information from the engine sensors to determine mixture and are adjusted automatically. On an older carb Ferrari, adjustments could and have been made to "mask" incorrect cam timing. <"The cams are Indexed and Marked by the Cam Profiler after the cam is cut and before it is removed from the Profiling/Indexing Machine. Therefore the accuracy of the internal marks are assured. Furthermore, Ferraris street cams are so mild in comparison that the few degrees of given innacuracies attributed to build quality/machining tolerances have virtualy no effect on actual performance or emmisions." I must say that Ferrari factory has stated to me that those cam marks are only for assembly purposes and not as a gauge for cam timing accuracy. Unless your eye can read in 1/1000 of a millimeter. And trust me, a couple of degrees retarded beyond specification on a Testarossa exhaust cam will have disasterious effects on your emissions. <"Max open is the best way...but in my experience, it ALWAYS leads to the notched marks on the caps being within less than half a line width inaccuracy." I can agree that may be a good way, and it is what is recommended by the porsche book.But the ferrari factory procedure has not failed me yet and I`m quite satisfied with the results. But I am open to change. Best regards, Jim | ||
| JRV (Jrvall)
Intermediate Member Username: Jrvall Post Number: 2240 Registered: 11-2002 |
>>The consequences of very slightly (6 crank/3 cam) mis-timed cams is also negligable,<< again I agree with Phil on this. The cams are Indexed and Marked by the Cam Profiler after the cam is cut and before it is removed from the Profiling/Indexing Machine. Therefore the accuracy of the internal marks are assured. Furthermore, Ferraris street cams are so mild in comparison that the few degrees of given innacuracies attributed to build quality/machining tolerances have virtualy no effect on actual performance or emmisions. Like Phil, I have degreed cams on Ferrari engines as old as 1953 212's and have consistently over the last 25+ yrs seen the internal cam marks align with the cam cap index line within the range of the thickness of half the line itself....additionally I have seen so many mistimed cams to loose count that had absolutely NO appreciable telltale signs on running condition and would never have been known without the visual inspection.. >>Max open is the best way...but in my experience, it ALWAYS leads to the notched marks on the caps being within less than half a line width inaccuracy.<< also agree that the best way to time cams is max open.... if one would look at the Porsche cam timing procedure they will note that Porsche (911)cams are not marked and have to be set with degrees, or more acurately Time & MM of Lift. | ||
| Phil Hughes (Ferrarifixer)
Junior Member Username: Ferrarifixer Post Number: 84 Registered: 7-2003 |
But if your clearance for timing purposes is set to 0.48, or 0.52 (or worse) rather than the perfect 0.50mm, your timing adjustments will be early or late depending on which. Max open is the best way...but in my experience, it ALWAYS leads to the notched marks on the caps being within less than half a line width inaccuracy. The consequences of very slightly (6 crank/3 cam) mis-timed cams is also negligable, and only effects the rpm at which the various performance/emmission outputs are achieved. I've said before somewhere, in controlled one make racing......cam timing can be played with to move the power band to better suit a given gear ratio if the gear ratios are fixed. | ||
| James J. McGee (Dr_ferrari)
Junior Member Username: Dr_ferrari Post Number: 158 Registered: 7-2002 |
Also, You are watching the point at which the cam lobe contacts the valve in reference to the degree wheel readings. That is why the two cyinders have to be set at .50mm Thanks and regards, Jim | ||
| Henryk (Henryk)
Intermediate Member Username: Henryk Post Number: 1112 Registered: 8-2001 |
Jim: That answers my question.......I didn't think of the difference in diameter, but can now appreciate it. The smaller diameter will definitely have more error in it. Thanks. | ||
| Henryk (Henryk)
Intermediate Member Username: Henryk Post Number: 1111 Registered: 8-2001 |
Jim: That answers my question. Thanks. | ||
| James J. McGee (Dr_ferrari)
Junior Member Username: Dr_ferrari Post Number: 157 Registered: 7-2002 |
Henry, The difference is the diameter of the wheel. the flywheel marks are more accurate due to the fact the diameter is larger. Also, do not forget that the Ignition signal comes from the crank sensor that picks up it`s signal from the flywheel. The flywheel machining and marking is much more precise than the cams. Best regards, Jim | ||
| Henryk (Henryk)
Intermediate Member Username: Henryk Post Number: 1110 Registered: 8-2001 |
Jim: That makes sense, however, if the cam marks can be incorrect, then why can't the flywheel marks also be incorrect?.......aren't both punched in by a human? With the degree wheel, are you physically watching the valves open and close? | ||
| James J. McGee (Dr_ferrari)
Junior Member Username: Dr_ferrari Post Number: 156 Registered: 7-2002 |
Both the internal and external cam marks can be incorrect. The ONLY way to properly set the cams is with a degree wheel (or the flywheel marks) and measuring intake valve open and exhaust valve close as shown in the Workshop manual. If you set the timing by just lining up the internal cam cap marks, You can be assured the cam timing is close but far from correct. JMHO. Best regards, Jim | ||
| Henryk (Henryk)
Intermediate Member Username: Henryk Post Number: 1109 Registered: 8-2001 |
I also thought that these where the "....only real marks". If the belts can be timed to these marks, then what is the reason for using a degree wheel?....assuming that one only wants to time things to original. | ||
| JRV (Jrvall)
Intermediate Member Username: Jrvall Post Number: 2239 Registered: 11-2002 |
>>Do you generally find the "internal" cam marks to be acurate,<< Uhhhhhhh...those are the marks I thought everyone was talking about????. Because they are the only real marks. You mean someone is trying to set cam timing using external marks? and without the tool used to set to the external marks? {  } Those little external marks and pointers are just a guide to aid in diagnoising problems ...and in emergency cases to aid in installing a belt and insuring the valves don't hit. All fully correct & accurate operations always reference off the internal marks that are indexed at the time the cam is made. btw: chains aren't really more accurate than belts and suffer many of the same ills over time. The most exacting way to set timing is with adjustable gears.. | ||
| Jeff Green (Carguy)
Member Username: Carguy Post Number: 458 Registered: 10-2002 |
Thanks JRV and PHIL for the eduction. Do you generally find the "internal" cam marks to be acurate, the ones on the cam and retainer cap? It seems that these are at least more acurate than the external ones. I guess a degree wheel is the only way to go. Yes JRV...these belt driven systems may be simple, cheap, and quiet. But I agree with you in that there is a lot of variation...you'd think for something so important as the cams (the engine's mechanical brain) that they would have used chains. Oops, there's another topic that has been beat to death. I appreciate you guys sharing your experience with me and the rest of the gang. I have never used a degree wheel before but do understand the idea. Looking at the whole picture I feel like burying my head in the sand. But if I take little steps, I may be alright. | ||
| JRV (Jrvall)
Intermediate Member Username: Jrvall Post Number: 2238 Registered: 11-2002 |
>>then, how hard do you shove the feeler gauge in...?? << { } | ||
| Phil Hughes (Ferrarifixer)
Junior Member Username: Ferrarifixer Post Number: 82 Registered: 7-2003 |
While dave Helm's theory is quite correct, The 3 deg misalignment effecting the emmissions so dramatically part is probably a bit exaggerated!! There's about 1.5 deg of play in the flywheel bolts, and as the belts get older and stretch a bit the cams gradually retard by a further couple of degrees, so the degree wheel is just a blueprint operation. The Ferrari quoted valve timings are based on a clearance of .50mm, which is way bigger than they run at, so you need to change the shim to get it right...then, how hard do you shove the feeler gauge in...?? It's really not THAT marginal. I always plot a valve timing chart on paper, then calculate the point of max opening of the valve within it's cycle. This way the clearance is irrelevant to timing, assuming symmetrical cam profile...which ALL Ferrari road, and MOST race engines are.... | ||
| JRV (Jrvall)
Intermediate Member Username: Jrvall Post Number: 2236 Registered: 11-2002 |
>>Since the motor is symetrical side-to-side with the same pulley diameters and distances from the crank, then I would think the teeth should also be in the same orientation. << Disagree with that theory. The reason there are multiples of adjustments indicates that nothing is exact or stays unworn & exact and there will need to be adjusting done to effect exact alignments. My understanding of the discrepencies between the factory marks and degreeing differences after the fact has more to do with wear and secondary procedures rather than the marks being inaccurate from the beginning. The marks are calibrated at the factory after the cams are profiled & degreed, so generally start out correct (within inhouse factory acceptable tolerances). Additionaly, if one looks at the system as a whole, the Belt Combination including pulley teeth is by far the least accurate in terms of thousanths of the entire system due to the nature of the parts, build quality, wear factors which include stretch and tension. | ||
| Jeff Green (Carguy)
Member Username: Carguy Post Number: 456 Registered: 10-2002 |
Thanks Everyone for your input! I am going to do the whole nine yards. JRV...I wasn't using the cam pulley teeth as an alignment method or anything, just a "symptom" of something else not quite right. Since the motor is symetrical side-to-side with the same pulley diameters and distances from the crank, then I would think the teeth should also be in the same orientation. That's all. So many reliable sources have now told me that none of the marks, external or internal, can be trusted. So I'll get a degree wheel and follow the procedure. | ||
| Philip Airey (Pma1010)
Member Username: Pma1010 Post Number: 380 Registered: 7-2002 |
Jeff At the risk of "selling past the close", the tech used a degree wheel to set the cams on my 308 - we were setting the [P6] cams at a different spec than suggested by the marks anyway. When he came to fit the belts the pulleys [sourced, BTW, from GT Parts in alum - perfect] wouldn't line up. Had to rotate the pulleys on the cams to get them exact - the pulley hole spacing appears to gradate by very small increments versus the teeth as you rotate precisely to deal with this situation. Philip | ||
| JRV (Jrvall)
Intermediate Member Username: Jrvall Post Number: 2235 Registered: 11-2002 |
>>The passenger's side cam pulley teeth are perfectly aligned to each other vertically,<< If I'm understanding this correctly , why are you looking at "pulley teeth" ????? Have you found a secret paragraph in the WSM that compares pulley teeth rather than alignment marks??? This reminds me of the guy that wanted the valve stems on his wheels aligned at 90 degrees to each other so that at speed the rotational forces of the protruding stem would cancel each other out. | ||
| Craig Dewey (Craigfl)
Member Username: Craigfl Post Number: 663 Registered: 1-2001 |
I agree with Phil too. Mine was off by about 1 tooth when I changed my belts. I assumed the last person wasn't as careful as me. I sleep better at night knowing I set it up better than it was before . I swear it runs more smoothly too(but that may be my imagination). | ||
| Dave Helms (Davehelms)
Junior Member Username: Davehelms Post Number: 99 Registered: 5-2003 |
I would venture to guess that around 25 to 30% of the stampings on the cams and caps are off as well. These stampings only tell you that the valves wont hit. If you go that far, time the cams properly with a degree wheel as the factory suggests. The factory gives a opening and closing point of the valve. If you are off by 3 degrees, and the cats are anything but brand new, it wont pass emissions, or will destroy the cats. If you are this far, do it correctly. Lining up marks, is just the starting point! Dave | ||
| Malcolm West (Ferrari_uk_tech)
Junior Member Username: Ferrari_uk_tech Post Number: 61 Registered: 7-2003 |
Agree with Phil, however the car would probably run okay, but the emission readings CO - HC would be out due to the cam timing. Our dealership in the UK ALWAYS removes the cam covers when doing a cam-belt service in order to verify the timing marks and correct if necessary, if a job's worth doing it's worth doing well. MW | ||
| Phil Hughes (Ferrarifixer)
Junior Member Username: Ferrarifixer Post Number: 78 Registered: 7-2003 |
Jeff You'd be mad to just leave it and hope for the best! After all this work, and with Labour for free, you should remove the covers, fit new cam seals and new O rings to the housings, and then check your cam timing and adjust it as necessary. Then, while you're there you may as well check the valve clearances etc etc. You'll sleep better knowing it's all done, promise! | ||
| David Feinberg (Fastradio2)
Member Username: Fastradio2 Post Number: 285 Registered: 4-2002 |
No problem, Jeff...more than glad to help. Been down the cam timing road quite a few times through the years. On my BB, there are no external pointers, so it's always valve covers off to set the cams. I'm only an hour from you, by air...five by car, if you get stuck, or need help. Best of luck, David | ||
| Jeff Green (Carguy)
Member Username: Carguy Post Number: 455 Registered: 10-2002 |
Thanks David I truly appreciate that offer. You know I think I will dig in all the way, gonna order parts tomorrow. HERE'S AN IDEA: When I get everything in place, I think I may just scribe my own (exact) timing marks externally instead of using those awful "reference" marks on the back covers. Has anyone else done this to their car? It sure would clear up a lot of confusion right off the bat! I can't see why the factory guys didn't do it. | ||
| David Feinberg (Fastradio2)
Member Username: Fastradio2 Post Number: 284 Registered: 4-2002 |
Jeff, The question of the car running fine "in this condition" is mute...The cam timing appears to be off and the correct way to set back to the precise factory specs is to remove the valve covers, align the cams with the marks on the end caps...assuring that the crank pointer is aligned at the PM 1/6 mark...and adjust the cam pulleys accordingly. Granted this is much more work than you had anticipated, but you've gone through a whole lot of labor to get to this point, why not do it "right", so to speak. In addition, you'll have the opportunity to check and adjust the valves, whilst you have to covers off. IMO, the reference pointer which are mounted externally to the valve covers are merely approcimate positions of the cams, and not intended for precise cam timing.... More work, more time...and more expensive, with the benefit that the engine will run 100%, verus just "fine"... Please feel free to contact me if you need extensive details on how to proceed... Regards, David | ||
| Jeff Green (Carguy)
Member Username: Carguy Post Number: 453 Registered: 10-2002 |
Thanks Preston for your two cents...that's why I posted, to get opinions. Kelly...TRs also have the multiple pin holes for getting the belt pulleys right. And this is why I question the mis-alignment. What started out as a crank seal replacement has snow balled into a nearly full blown service. Since I've done about 80% of a service now, and the next scheduled service is in about 3 years, I guess I ought to just go the whole distance and extend that next service out to 5 years. If I could rationalize the mis-alignment through measurements, or a difference in belts, I would not do more work. But I have checked everything to the thousandths of an inch, and cannot see why the pulleys should be this way. All I can say is I've learned a lot about Testarossas from working on mine. If all goes well with my car, I may consider doing this for others if there is interest. A private individule like me would take maybe two weeks and charge perhaps....well....I better think about this before my mouth overloads my butt. Thank You for your input. | ||
| Kelly (Tifosi1)
Member Username: Tifosi1 Post Number: 726 Registered: 2-2002 |
Jef, that's why on a 308 there are pins to rotate the Cam gear without moving the cams, thus adjusting for the different belts you will get. My 2cents. Kelly | ||
| Preston Davis (Pdavis)
New member Username: Pdavis Post Number: 24 Registered: 4-2003 |
My two cents. If the car is running fine with this condition why not just leave it alone. Or put another way -- why are you looking for a problem if, as a practical matter, none exist? pd | ||
| Jeff Green (Carguy)
Member Username: Carguy Post Number: 451 Registered: 10-2002 |
With the motor at top dead center, I've locked the cams into position. I've pulled off the belts, and the old tension bearings. But there is a confusing "situation"...it may be nothing but my over reaction but I need some advice. Problem: The passenger's side cam pulley teeth are perfectly aligned to each other vertically, like a mirror image of each other. The driver's side cams are about a half a tooth off and if moved vertically together would mesh like gears. The reference marks and rear belt cover pointers show they are aligned. But I just can't get comfortable with this apparent discrepancy. I've used calipers and measured pulley diameters, and distance between their centers, and both sides are identical. I can take swap the belts across each side and they fit perfectly too! The car seemed to run fine when with this condition. How can these pulleys measure the same and two belts fit the same, yet the teeth are not in the same position? I'm thinking I may have to do what I did NOT want to do and that is pull the cam covers and check the "master's marks". What do you guys think? |