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Cam timing question

Discussion in '348/355' started by markgllc, Jun 22, 2009.

  1. markgllc

    markgllc Karting

    Dec 25, 2008
    179
    Fairborn, OH
    I have read many posts about how important it is to properly degree the cams when replacing the Tbelt and read that you can't go by the "marks" and just change the belt. I do not understand why...

    I am considering doing my Tbelt myeslf as I was just quoted $7K *a guesstimate) for a major from a garage that does Ferrari work based on what I think I'll need...they have not seen the car yet so that price may vary + or -...probably + LOL when they see it.

    My question is this: if the car is running fine and you verify where everything is before taking the old belt off...why can't you lock everything down and simply install the new belt? If nothing changed ie cams were not unbolted ect...why could you not simply install the new belt providing everything was lined up and locked down when you took the old belt off? Install the new belt, rotate the engine by hand and ensure everythig is still lining up correctly....walla, done. I understand it's a Ferrari but there's olny 1 "right" way for everything to line up. If you establish those "marks" before taking your belt off...and put it back in exactly the same spot with the new belt...why would you need to dergee it?

    I can see the need to degree it if you totally take everything a part but I don't think I need to do that...I can tell my cam seals were done (fresh gaskets) and the engine doesn't leak a drop of anything. I just need a new Tbelt/tensioner and will also replace the oil pump tensioner and water pump when I'm in there.

    It appears my car has had a lot of service done to it as I see lots of what look to be new gaskets and the subframe bolts are new. It has a new alternator also...so someones been in there recently. I don't have any proof ie documentation on what service has been done which is why I want to do the belt so I have a good starting point and some piece of mind that my valves won't become close friends with my pistons. The car runs very strong...no smoke...starts right up everytime, NO LEAKS. I don't want to chince out on the service but don't want to spend money redoing stuff that just been done either because there's no document saying it was done. I am thinking: new Tbelt & upgraded tensioners, new water pump and oil chain tensioner and I'd be OK unless I find more when I get in there.

    Is my thinking all wrong? If the timing is lined up properly to begin with wouldn't everything be in the exact same spot with a new belt when you are done? I am a novice to this so be gental if I am being ignorant but don't want to discard new parts either if there's no good reason to do so. Common sense tells me there's only 1 right setting and if it's correct to begin with and you put it back in exactly the same spot...how can it be wrong?

    Sorry to start yet another Tbelt thread...but I need some advice. The opinions may vary but might help me decide better how I need to go about this. I've done timing belts and chains on other cars but this is my first Ferrari engine. I feel I can do the job mechanically speaking but have no hands on experience with this specific engine. Many thanks in advance... MarkG
     
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  3. Rifledriver

    Rifledriver Two Time F1 World Champ

    Apr 29, 2004
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    How do you know it is fine now?

    Most of the cars that come in here the cams are timed wrong and in most cases the owner didn't know.

    Ever see a post about slow down lights?

    Ever see a post about bad cats?

    Ever see a post about check engine lights?

    Ever see a post about failing smog?




    If you want to take short cuts, its your car. But get ready for an "I told you so".
     
  4. ernie

    ernie Two Time F1 World Champ
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    #3 ernie, Jun 22, 2009
    Last edited: Jun 22, 2009
    Since you have done work on other cars you should have no problem working on your Ferrari, just get over the fear of the name.

    Now.

    Since this is the first time you are going to change the belt on your 348/355 (dunno what model you have??) I would find out how things line up first. As Rifledriver said, "how do you know it's fine now".

    So ....... find TDC on the #1 cylinder and then see how everything lines up. Then after you have verified that everything lines up properly, or doesn't, you can either get set things straight or go ahead and change the belt depending on what you find. Then the next time you go in all you'll have to do is put everything on the marks and swap parts. But for the first time you should verify things. It's a little more work but in the long run it will make things easier.

    As for lining things up there are a few schools of thought on this.

    The 1st is to find TDC, find the opening and closing of the cam lobes, and then adjust the cams so that they are opening/closing according to the specs. This way you know exactly when the cams are going to open and close relative to the crank position.

    The 2nd is to find TDC, and then set the cams to the factory cam marks. Doing it this way you are relying on how accurate, or inaccurate, the cams where lined up at the factory before the cams and cam caps where marked.

    The 3rd is to time your cams while you have the engine on a dyno. The factory specs usually have compromises in them to meet emissions, or fuel ratings, and aren't always timed to make the most power. So if you are timing your cams to make the most power, or to make power in a certain rpm band, the best way to do that is to time the cams while it's on a dyno. That way you can play with the timing all you want until you are happy with the power the engine is putting out and where in the rpm range it's making that power. You'll still have to start at the factory specs, but then you can advance or retard to cams to see what the engine likes best. Once you have found the sweet spot you are good to go. The down side of this method is that dyno time is not cheap.

    How did I do it?
    I trusted the factory and lined things up to the factory cam marks. I was being a lazy butt and figured, if it didn't blow up the way the factory mechanic lined things up I'll just do what they did and be done with it.
     
  5. markgllc

    markgllc Karting

    Dec 25, 2008
    179
    Fairborn, OH
    I'm not saying I want to short cut anything...in fact it's quite the opposite but I don't know these cars which I why I asked the question.

    On the other hand I don't want to do things it may not need either. My question was: IF the cams are timed right to begin with, is it required to degree it? I have no warning lights or anything showing me I have a problem. Not to say I my timing is dead nuts on...I don't know and that was a very valid point you made.

    Again not looking for a shotcut but was trying to understand why the degreeing would be needed if it was right to begin with and you put it back the way it was when you were done. I figured I'd get some folks going as this is a vary touchy subjuect especially to those that have lost a belt. I was hoping I didn't come off like I was wanting to cheat because that's not what I will do. Just trying to understand where I'm at, what I should do and the process. If everything was taken a part then I'd understand degreeing it. If it's all going back like it was...what is degreeing going to do for me other than verifing it was right to begin with? That was more what I was driving at not if my timing was right to begin with.

    Your knowledge is vastly superior to mine as I have basicly none LOL so if you say you see them setup wrong all the time and folks don't know...then yes, degreeing it is probably what I should do.

    I know the cam timing can be off and still "run" but wouldn't you notice that when driving it or see some indication it's wrong like a miss, smoke, overheated cats or something...mine doesn't seem to have any issues other than the unknown. I am trying to verify from the past owners what the history really is but if I can't determine that for sure...I'm going to play it safe rather than join the "my timing belt broke" club.

    I am not against doing the job right at all which is why I asked in the first place. If I didn't care...I'd just slap a belt on it. I like to understand why I am doing something though and if everything is going back the same as it was, I didn't see the need to degree it. I respect your knowledge, heed your warnings and appreciate your comments.

    Many thanks...MarkG
     
  6. markgllc

    markgllc Karting

    Dec 25, 2008
    179
    Fairborn, OH
    WOW I got a reply from Ernie!! I've read your posts man...you've been through it all brother.

    Your reply was exactly what I wanted to know.

    Yes I will admitt I am somewhat intimidated by the fact it's a Ferrari but had the same fears when I started working on my Maserati. After I changed the belt (prevenative) my hand was shaking so bad I could hardly turn the key. I had checked and rechecked about 10X that it was right but still...I think you understand that feeling. It started right up and no problems to date.

    This 348 is the nicest car I have ever had...and so far I have done great fixing all the little stuff. It's coming easy to me after working on the Maz as it's very similar but dropping the engine isn't for the faint hearted. I'm a gearhead and have worked on all my own cars for years and many marquees: Triumph. Mercedes, Alfa Romeo, Fiat, Nissan, Volvo, Chevy and many more. I've also restored a few. Never had any real problems I couldn't figure out on any of them....but I don't "know" Fcars...not yet anyway. I am hoping to one day maybe be a stooge but I have to work my way to that LOL.

    Thanks again Ernie...MarkG
     
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  8. Rifledriver

    Rifledriver Two Time F1 World Champ

    Apr 29, 2004
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    #6 Rifledriver, Jun 22, 2009
    Last edited: Jun 22, 2009
    You may or may not have symptoms. The ones you might have may not be noticable, the point is unless you have timed it you do not have any way of knowing if it is correct.

    I know you didn't use the word shortcut but to avoid doing it that way is one, verbalize it or not.
     
  9. markgllc

    markgllc Karting

    Dec 25, 2008
    179
    Fairborn, OH
    Thanks and I totally understand your point. I didn't get my feathers ruffled up hope I didn't fluff yours either ;-) As I said I know nothing 348 specific but have worked on many cars and done belt(s). In the past all I've had to do is line everything up and was wondering why degreeing is required if it was right to begin with. That was more my question.

    I understand now why it can be considered a shortcut ie if the timing is wrong to begin with, you're basically putting the belt on wrong...again. That's what I was wanting to know.

    Many thanks...MarkG
     
  10. Rifledriver

    Rifledriver Two Time F1 World Champ

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    No problem. I was just trying to clarify a point.
     
  11. markgllc

    markgllc Karting

    Dec 25, 2008
    179
    Fairborn, OH
    And your point is right on the money and well taken. Like I said, I have no knowledge and based on my other belt changes I saw no reason why if nothing had changed what degreeing would do for me. I didn't consider that it could be off to begin with.

    That's why I ask you guys ;-) you know the answers...I don't. Many thanks again..MarkG
     
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  13. ernie

    ernie Two Time F1 World Champ
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    Mark the point Brian is making is this.

    There have been instances where the cams didn't even line up to the factory cam marks, and this is even after a fresh engine out service. So if you just keep things locked down where they are, swap the belt, and then go, you have no idea of how the cam timing was lined up? That is why it is just better to check things out first. If the previous mechanic's work is worth a damn the timing should be within the specs, or at the least line up to the marks. But again, you won't know that until you check.

    So before you remove the old belt line up the #1 cylinder to TDC and see how the timing looks. It's not hard bro, especially since you seem to be handy with a wrench.

    Lefty loosey, righty tighty. ;)
     
  14. angelis

    angelis F1 Veteran
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    Jun 18, 2004
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    Stoopid question......

    The marks refered to, are they the ones etched on the cams which are then lined up to a mark etched on the cam housing?

    If those marks are lined up, would you still need to degree the cambelts afterwards?
     
  15. ernie

    ernie Two Time F1 World Champ
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    #12 ernie, Jun 22, 2009
    Last edited: Jun 22, 2009
    Yo Sy, waaaasssaaaap.
    Yup

    The caps are the things that hold the cams to the head.

    For me, if #1 is at TDC and the marks on the cams and caps line up, I'm good to go. The way I figure it is, if the boys at the factory lined things up, marked the cams and caps, fired it up, drove it off the assembly line, and the thing didn't grenade, if it was good enough to roll out of the factory then it's good enough for me.

    But.........

    Are the cams timed perfectly? Won't know until the actual opening and closing of the valves are compared to the position of the piston. And that will require a full on cam timing session. Is it making every ounce of power that it can make? Won't know until it gets slapped on the dyno and, a full on cam timing session is done until no more power can be squeezed out of it.
     
  16. markgllc

    markgllc Karting

    Dec 25, 2008
    179
    Fairborn, OH
    You guys are great...I am glad I asked although I knew another Tbelt thread is just what everybody wanted to see. Sorry for that but many thanks for the enlightenment and the encouragement.

    Based on time alone though, if the Tbelt was done in 2006 it's due anyway....right? Some say 3 some say 5...mine is at 3 years IF my info is true. Logically speaking I can do it now and be driving a car I am confident with or wait a year and basically spend the money then providing nothing bad happens...I've been to Vegas...don't usually do too well...that should tell me something LOL.

    It sounds like I just need to just Nike the belt and associated components and get on with production. It's only money right LOL and if I wait and it goes KABOOM it'll be even MORE money IF it's repairable...I'll take the lesser of 2 evils LOL thank you.

    I guess there's really nothing left to ponder...it's a no brainer. Looks like I'll be doing a belt change or getting it in for the work soon.

    See it wasn't hard to bring me around...just needed a wallet reality check from the brotherhood...thanks guys.

    MarkG
     
  17. ernie

    ernie Two Time F1 World Champ
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    Turn the wrenches yourself Mark, it's not hard. Plenty of guys on here have done it and you can too. You will learn a TON about your car in the process, and you'll save loads of money.

    You can do it.
     
  18. markgllc

    markgllc Karting

    Dec 25, 2008
    179
    Fairborn, OH
    Thanks Ernie,
    I am sure I could do it however my garage is a total mess right now...have a Maserati that needs a new home and my Mercedes 450SL is in it's final stages of restoration...then there's a 59 Triumph TR3A tucked away in the corner...then a Fiat an Alfa and a Subaru in the drive way ALONG with a Hugh Jass Formula boat....my place is simply maxed out. I would love to do it myself and sure I could do the job, but don't have the room at the moment.

    My original game plan was to sell some cars BEFORE I bought my Fcar...I only added to my cramped quarters. I may have to enlist a shop for this one and prepare myself to do the next one.

    I have been thinking about how I would go about it though...everybody suggests a lift and I see the value in that to get it up to get everything disconnected but when you are ready to "roll the engine out" don't you still have to lift the body somehow? I was wondering if it's feasible to connect a lifting bar to the shock towers (after unbolting the shocks) and raise the car with a winch without damaging anything? After the engine is "dropped" ie subframe is removed how heavy is the back end at that point? Just wondering how everybody raises the car once everything is unbolted or am I not seeing things right...again LOL. I'm new to this so don't slam me too hard...I don't know which is why I ask. Trying to "see" the process in my mind and determine what others have done so don't have to reinvent the wheel.

    MarkG
     
  19. ernie

    ernie Two Time F1 World Champ
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    DO NOT lift the end of the car via the empty shock tower mounting points on the body. It WILL bend the crap out of the body. Again DO N O T lift it via the body, you WILL bend the rear.

    If you don't want to use a lift you can use two floor jacks to get the job done. That's how I lifted the body off the subframe when I did my engine out service the last time. Two floor jacks works fine, but a lift does make it easier.
     
  20. markgllc

    markgllc Karting

    Dec 25, 2008
    179
    Fairborn, OH
    Thanks Ernie...Not to worry brother I'm not doing that just asking if there's a way to lift it without causing damage...thanks for the answer.

    As I said I'm not going to probably do this one myself no room. I wasn't sure if there was a way to raise it from above verses jacking up on both sides. Seems to me that would be easier if possible...from your reply it sounds like a REALLY bad idea LOL. Sorry if I made ya rupture a Ferrari vessel, you've been through enough...I could see the veins poping out on your forehead from here LOL Sorry. MarkG
     
  21. AceMaster

    AceMaster Three Time F1 World Champ

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    #18 AceMaster, Jun 23, 2009
    Last edited: Jun 23, 2009
    When doing the next major (which will be my first since owning this car), is there a way to tell if the timing was done wrong previously? And once it is set properly, does it ever get out of the correct timing setting? Sorry for such a novice question, but i am trying to learn myself. Thanks on advance
     
  22. markgllc

    markgllc Karting

    Dec 25, 2008
    179
    Fairborn, OH
    The only way to KNOW for sure if the timing is correct is to degree it. That's what the brotherhood cautiously schooled me on today. Read the post...it's told that many cars are not set right. The marks may or may not be correct. If your timing is off to begin with, simply changing the belt will give you a new belt but your timing will still be wrong. From what I understand it's not uncommon for it to be off and the only way to know for sure that it is right...is to degree it. If you look at what the experts told me earlier in this post...you'll know why you should check it.

    That's why I asked too...I didn't know. That's how we learn...Ernie provides some really helpful information as does RD. MarkG
     
  23. angelis

    angelis F1 Veteran
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    Thanks Ernie :D
     
  24. Rifledriver

    Rifledriver Two Time F1 World Champ

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    Except he is wrong. The factory didn't do it that way. Never did, since 1949.
     
  25. Ferraripilot

    Ferraripilot F1 World Champ
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    I can tell you my personal experience with the factory timing marks is they are sometimes right. I only know this because when I degreed my cams 3 years ago, the front bank cam marks from the factory were dead-on correct with what my degree wheel was showing to be correct while the rear bank was off a couple degrees on the intake cam. The true TDC mark for 1-4 was off about a degree as well. This was on a '76 308gtb.
     
  26. ernie

    ernie Two Time F1 World Champ
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    Okay.......

    So why does the factory mark the cams and the caps then?

    I'm willing to learn if your are willing to teach.
     
  27. gidge348

    gidge348 Formula Junior

    Dec 12, 2008
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    Perth West Australia
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    Ian Wood
    Mark I would strongly recommend that you DO NOT get the job done by someone else you WILL regret it...... do it yourself if you have a modicum of mechanical sympathy.

    If you need space, push one of the other projects out in the rain or find some space somewhere else for the projects to go you, don’t need a huge amount of room, 2 car bays area would be fine.

    These cars are not hard to work on as a matter of fact in a lot of ways they are easier than many mass produced cars, but they do take a lot of care and attention to detail, I have yet to see a shop that cares more about a car than the owner……

    My car was serviced from day one at a major dealer and the level of workmanship was horrible. http://www.ferrarichat.com/forum/showthread.php?t=225152&highlight=348+burnt+valve

    Once you get the engine out (need 2 jacks, 2 people & 2 hours).... Then check EVERYTHING, put a degree wheel on it before removing the belt and just see if it is correct may be right may not be (I would be betting on not). Check valve clearance, cam gear fences, everything.

    Once you have done that you will KNOW it is correct and have learnt a hell of a lot, the fun of driving will be much higher.

    Do it yourself & enjoy
     
  28. ernie

    ernie Two Time F1 World Champ
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    #25 ernie, Jun 24, 2009
    Last edited by a moderator: Sep 7, 2017
    Since I don't want to be one giving out wrong information to the Brotherhood, or anyone else for that matter, I pulled out my hard copy of the workshop manual and had a look at what the factory had to say about the matter.

    The 1st pic says to fit the cams so that the notches are aligned perfectly, and then do the same to the other head.
    The 2nd pics say to put #1 piston at TDC and make sure the marks on the cams line up with the caps
    The 3rd pic say turn back to TDC and make sure the marks are still aligned.

    Hmmmm?

    How is it again that the factory hasn't done it this way since 1949?
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