I was out skiing an early winter storm and did not know this thread was reserected from the dead. Anyway Verell is correct in what he writes. I did not re-read what I wrote but basically about finding true TDC Verell is correct. I happen to use a dial guage but you could do the same thing with a piston stop which is how most v-8 chevy guys do it. Both work. The advantage of a piston stop is you dont have to read a dial guage. There are other ways too like a whistle. Basically you cannot begin to degree a cam until you find true TDC. If you dont have true TDC everything else you do it wrong. To Greg I use matchbook covers under cam caps not to lock cams because we are not replacing timing belts but we are degreeing cams to ensure the belts and cams are in the right relationship to each other. You use a camlock or my crude way to lock a camshaft in position and just slap belts on when you are in a hurry. This method is basically using a nail instead of a proper cotter pin. Both work which do you want to have? I use matchbook covers in caps to lock a camshaft down that I want to torque or lossen a cam bolt to set a cam cog or remove a cam cog. IMO I think you need to degree cams in your car always for max performance new or old. I think you need to do it at least once to see where your marks are relative to true degreed positions and then you can be lazy if you want. I also think you can just use the timing marks and forget about degreeing all together and have a consumer acceptable running engine. I believe that 99% of real mechanics do it this way and 1% are degreeing cams the best way. It is threads like these that not only educate owners who may have no intention of doing it themselves but also raise the bar for diyers and raise the bar for pros because they know more owners are expecting this level of detail. Paul I do not think it matters whether you use the opening method or the centerline method as long as the lobe is symmetrical. They are both equally as accurate. John made the point about symmetrical lobes for the centerline method and he is correct on that issue but it is unproven whether the 348 lobe is symmetrical or not. This thread was not only informative but exploratory and exposed some uncertainties of Ferraris documentation. In this thread I proved in this one datapoint on my engine that not only were the marks spot on but that the timing could be verified by either the opening method or the lobe centerline method yielding exact measurements per Ferrari specs. Therefore I assume that the lobe is symmetrical. In this example the centerline method confirmed the opening method and vice versa and both methods lined up with the scribed marks.
First idea is a great idea. Do you put them under all caps or only a couple? Excellent point about 348 symmetry. I am guilty of assuming it was asymmetrical. Thank you for such an excellent writeup when you started this thread. It just goes to prove that there is a massive amount of data on this board but we often don't search to find the jewels.
I used this method just on the end caps next to the belt gears, and it worked great to hold the cam in place on the cam marks while I installed the new belt.
An interesting thread. However, we found when racing, that we would make better power when we set the cam timing by the lobe centers. Getting those exactly where we wanted them, produced the most power. The problem is that the cam lobes aren't alway the same from lobe to lobe. If on the other hand you've got the centers degreed in, then you've essentially got the same breathing in all of the cylinders. Worked for us. Art
And while I havnt voiced it, this is why I dont believe the opening points are any more accurate. Unless someone was anal enough to check every single lobe, unless you are anal enough to adjust clearances so all opening points are exact, its impossible to reach total perfection. But when you see your camshaft index mark is 20+ degrees out of proper alignment, you know for a fact these engines need to be degreed. I first heard of degreeing when I was about 12 or 13. A guy working on plain old Chevy's told me he never seen a cam that was true or even indexed all that close. He would check a cam on V-blocks and record all the opening points, and re-index the cam to a point midway between. That way the majority would be "about right". Some manufactures run pretty tight tolerances, some have wild variations, and your just not going to know without checking. When I have some time I will play around and see how close these 308 cams are. I have heard they can be vary wildly lobe to lobe, but it would be nice to see for myself. I have a feeling they are pretty close.
Greg I think this way too. I am skeptical about variations with todays manufacturing ability and todays design ability but I have never bothered to measure lobe by lobe now was there anything I could do about it anyway. i would be more willing to check a custom valve grind because more people are involved in the process. Today even tires and wheels are so good that on the racetrack at speeds over 100mph I make sure wheels are balanced and they mostly are perfect and just put rubber on without balancing because everything manufactured is so good and I can't feel any vibration. Those are pretty gross items but does speak to manufacturing capabilites and how far we have come from 20 years ago in wheel tire manufacture. I remember wrenching on 308's and dinos and how stuff would not fit and parts on some cars had to come off for access but you can work around them in other dinos. Today every 355 is the same every 360 is the same. It is amazing how far we have come dispite the amount of stuff still done by hand at ferrari.
Agreed. The key to Artvonne's statement was "plain OLD chevy"? With todays CNC machines, every part can be duplicated perfectly. (Or as close as possible)
Or as someone else once said, ever wrong part can be duplicated perfectly I think it was in reference to some screw up at Hyundai where they had to recall 1.5M cars because of some design flaw. Computers and robots dont see mistakes. I havnt ever bothered to check a cam either, but I know even a few years ago I read in some hot rod or import magazine about people seeing flaws in lobe syncronization even among some top camshaft manufactures. But like FBB said, what ya gonna do about it? At least with a Ferrari you could simply find some good middle area by pushing the extremes equal distances apart early and late.
It stuns me to think that we are computer controlling engines today but can grind perfection into cam shafts! Holy smokes!
I understand, but we are talking high tech products here. Why should anyone have to check them? That is expected in the purchase. Think of it this way. I spend $350K on a 599. Do I expect those cams are not properly ground?
I no longer have very high expectations, in fact they are lowering by the day the older I get and the more I see. If someone can screw up a part, all they need is a computer to help them screw up even more parts. All the computer has done is let us make 10 times more parts in the same amount of time as conventional machinery with much greater accuracy part to part. So if the input data was screwed up, you just made 10 times more perfectly identical screwed up parts. And if no one is going to check them because of all that percieved high tech accuracy, out the door they go into the world, where maybe you get one of those high tech products that you expect to be perfect. And unless its a major blunder, no one might ever be the wiser. If the factory didnt catch it, and if no one complains, the factory itself may never know they goofed.
When i was younger, and first sew the Ferrari 355 i thought it was a really high-tech car. Now when i have one, i only have one thing to say about it - It aint a high tech car. Definetely not. Its just a mechanichal car. The engine construction is very simple. If we are gonna talk about high tech cars/motors, maybe we shall move to Bmw:s, or Hondas engines... Variable cam timing, Variable intakes, Valvetronics, Super high-speed ECU/electronics with millions of measuring points and so on... Ferraris are Passion, cars with feelings, but definately not high-tech. Maybe these later models are, but not the older ones. And Ferraris quality of assembling... Definetely not compareable with other Car-makes... Kimmo /// Sweden.
I don't doubt that there have been valve opening/closing differences in lobes on the same cam. The manufacture of them have come along way with the invention of the Spintron though. In pro stock, with very high spring loads (like 400# closed, 1000#+ open) we had problems with the camshafts twisting. GM pro stock engines ended up going to Ford journal size to help, but it still happens. One way to band-aid the problem was to adjust ignition timing on each cylinder. Small differences in the static part is one thing, but people would **** if they saw what is actually taking place in a running engine at full RPM!!! Steel/iron/and aluminum move and flex more than most people would think.
You are right on about this. I do biz with some of the biggest brands in the U.S. They have been trying to outsource everything (no surprise) but what really cracked me up is how they put the "quality" issues solely on all there vendors and basically have started telling them "we don't even want incoming inspection ... if something is wrong with the parts you supply and we install/ship them you will be responsible for return shipping costs & rework" ... paraphrasing terms on purchase orders. So basically fly by night companies get these massive contracts from well branded companies, deliver crap products, get paid and shut the doors before the big company has a chance to "excercise there rights" in the P.O. ... what a joke ... in a perfect world it's a great concept but manufacturing is far from perfect ... that's why there's tolerances and different engineers put different tolerances on things . I'm not sure if it's got this bad in Europe/Ferrari but I'm sure the guys running these companies learned this is the "right way" from some book or biz school ... like JIT manufacturing ... for those of you that don't know what that is it's when you don't stock any inventory and just build everything to order ... that's why delivery dates started becoming so important because everyone was late delivering because they carried no inventory and their "spreadsheets said" this project/product should only take 90 days or months or whatever ... then someone like me actually measures something they're assembling and all hell breaks loose 'cause you got no rework time ... I know ... some manager looking at a spreadsheet is gonna pipe in "rework means someone made a mistake which is unacceptable" ... which I would now reply "don't you have a tee time or something to get too .. piss off" . We were making this one frame assembly and the engineers and the incoming q.c. did not know how to check what THEY had put on the blueprint ... I am not making this up. This was a big company and I said "how do you expect us to give you good product if you can't even check what you designed?" ... he handed me a 4 page document which explained how to check the part which the engineer didn't even understand ... the part couldn't be made to the blueprint spec's so they had all these "scenarios" that were okay ... just pathetic! That was when I pretty much stopped interfacing with them myself and started sending someone over to just give lip service which is really all they wanted. I actually wanted to understand how to check the part ... they just wanted someone to tell them "we can do it" so they could check if off on their daytimer or whatever planner is cool these days . cheers
Steve that did Nick's 4.0L is nearby and he has a cam profiler which gives you not only lift and duration but: velocity acceleration jerk Talk about TMI (too much info), but after my cam failures had no choice but to start looking at all these relationships . He just profiled a cam for my buddy and there was a flaw in the original cam that was copied to the new one ... the cam guys will probably tell him "it's within tolerance". Happened with some valve springs .... they were standing straight when I installed them ... leaning to the side after 175 hrs ... was told "they were probably like that when you installed them ... our tolerance on how square the spring is +/- 1 degree" ... which is "about" .017"/inch. I didn't get into a yelling match with the guy how I'd checked them before installation ... just making the point that just 'cause you're paying "silly money" doesn't mean it's right/high quality/"world class" as the spreasheet management like to call it LOL .
I know they finished the 3.5 liter (dyno is on the Carobu site), but I never saw anything where they finished or ever had a 4 liter running. Would love to hear or see photos of how that turned out.
yeah you're right they didn't finish that yet 'cause the typical $$$ flow but I think they're getting ready to get back on it ... I think 'cause they want to run the 4v head to get a "worthwhile" amount of power it kinda stalled things 'cause means all the cams, etc. need doing for those heads. I'm contemplating doing the 3.5 now I've got the ITB intake sorted. With the stock plenum intake I guess I wouldn't make the power that Nick did and I didn't want to spend the money on the TWM's ... geez then there's the cams ... those are some monster cams in that engine ... using every bit of the shim under bucket ... now I remember why I shyed away from it ... my engines are on a lawnmower budget in comparison . cheers
Yes, I thought that $$ might be it - I can relate. From what I remember, all of us are on lawnmower budgets compared to that engine. For those who did not get to follow this amazing engine, it was a 308 2 valve taken out cost-no-object to a whopping 3.5 liters with titanium internals, wild cams, ported head, 10.25:1 pistons, Electromotive Ignition and ECU and the TWM throttle bodies. On the ENGINE dyno (not rear wheel) it made 338 horsepower and a 269 ft-lbs of torque. http://www.carobu.com/html/308_gtb_3_5l.html
This post needs to be bumped.....great post FBB and others. Just degreeing my cams and a couple of silly questions someone may be able to answer. 1. The 348 engine turns the normal clockwise as viewed from the front..... Why does the timing diagrame show direction arrows ANTI clock wise? 2. Other diagrams I have worked with show intake on the centre line and exhaust on the outter line... How can we know that in this case intake is the "Outer" does not seem to say in the WSM? 3. If the timing diagram is describing "cam" angles and not "crank" angles we would have cams with 240 deg+ dutrations, this is obviously not the case why do the numbers only work using "cam angles"? Or are these all mysteries of the italian translations.....
Great write up, i do have some questions. What does angling them at different angles do? increase performance? Visit donate2wade.webs.com
They're taking this from the best Japanese companies that have been doing this since the '80s. Part of the culture that Demeng helped them develop. I remember studying it as being one of the techniques that helped bring Japanese auto makers to the forefront of cost effective high quality production. Unfortunately, It sounds like it doesn't work here. I suspect it works in Japan because of their strict sense of honor combined with their corporate practices of cultivating decades long relationships with suppliers. Different things work/don't work in different cultures. I remember hearing that Bell helicopter has a similar vendor quality requirement. However, periodicly they bring in the senior management from their suppliers, walk them thru the plant showing where each of their parts goes on a helicopter. At the end of the tour, they walk out onto a landing pad & are invited to take a ride in a just assembled helicopter. Those who refuse the ride get their contract terminated very quickly.
