Setting the cam timing belts on a 355

Degree Wheel
Cam Pulley Locks

 

Cam pulley locks?


Why?

 

How else do you keep the proper timing when re-installing and tensioning your belts?

 

The procedure is a lengthy one that I have offered to write up before and always turns into a pissing contest so I will just not be bothered to try again but it does not include holding the pulleys.

If you have done it the proper way and know what the pulley locks are for please enlighten us all.

 

I'd say that it is obvious that pulley locks...lock the pulleys...preferably with the cam pulleys already set to the correct timing positions. That would also seem to me, a layman, as the safest way to insure that the cam timing you set is the cam timing that you get.

If there is a safer way to set the cam timing without using pulley locks then perhaps that would be a likewise acceptable method of setting proper cam timing.

I'm sorry to hear that such a method has experienced on-line controversy for you, but I'm not altogether surprised (if you are getting away from cam pulley locks, surely you'd expect people to be shocked out of their comfort zones).

 

Crap...What the heck is the online controversy? sounds like your trying cover up your lack of knowledge. hahaha. Here we go again advising people on something you have never done. I have done several cam belt changes on 348s and 355s and have never needed to lock the pulleys. If you lock them into a postion how would you adjust the timing. Just because you think the timing is correct before you started the belt job how do you know its right? you should always verify the cams and their relation to one another and to TDC using factory specs.

Chris, when you remove the cam covers on a 355 you will see some marks on the cams(pulley side)when cylinder 1 is a TDC and a corresponding on mark the frt. cap the holds the cam in the journel, these can be used for a reference piont. they are not always accurate ie; they need to be verified. Using a degree wheel and a dial indicator you can verify TDC and cam postions and their relation to each other. There are also marks that are stamped on the rear of the cams and their related caps that are put there by the engine assembler these are more accurate. I would still verify those too and make notes for the next belt job as to your findings of those cam marks. I even take pics of my jobs for future reference. Regards, Vern

 

For reference, go here: http://www.ferrarichat.com/forum/showthread.php?p=135723056#post135723056

http://www.ferrarichat.com/forum/showpost.php?p=135731349&postcount=22

 

That is a post for a 308 not a 355 and secondly if you trust your existing timing marks use that technique. Do a search on timing marks and the problems people have had with the factory marks there was one just a few days ago. You read that one you posted to it. ie, 355 engine burble. You need to verify the cam timing that is all there is to it.

 

Locks in place for belt change, not for cam timming
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That is my whole point you do not want to just do a belt change. And even if you did I have never found a reason to lock the cams in place they have never moved on me to warrent the need. Although I have used the paper clamps concept on your left hand bank(rightside in your pic) Regards, Vern

 

Vern, I meant that the locks come off for cam timing, I timed the cams later, of course without the locks, and you're right, the locks are really not necessary. I used them only for breaking the bolt loose, and tightening it again after all was done. It was my first and I had been led to believe that they were necessary for a belt change, I found out after the fact that they were not.

If the engine is at TDC, the cams won't move, but I didn't know that at the time.

 

The reference to the thread on what can happen with bad cam timing by not using proper technique or using the factory marks which in my case were significantly off is in this thread = http://www.ferrarichat.com/forum/showthread.php?t=121381

If you are not using a degree wheel and carefully going through the process assuming the factory marks are wrong you are making a hugh and costly mistake - I wish Vern would post his process. this thread shows that ignorance of the correct process abounds and it is time for a truly knowlegeable someone to write it down.

 

Ah.. I see, nothing wrong with extra precaution when doing something the first time. regards, vern

 

Actually Rifledriver is the one that got me in tune(no pun intended) to degreeing cams( also reading some of Dave Helms posts on the subject). I used to be under the mind set that if the engine ran fine before the belt(s) change, then just check that the factory cam marks are lined up(hell the factory should be correct, right?) so they are at TDC and use a little paint mark on the crank to mark its TDC postion in relation to the factory cam at TDC marks and change your belts. In a sense don't move anything from where it was and your good to go. As I find out from guys that do this all the time that there has been some discrepancy in what the factory has done, it is not always what we think as Dave T. has had 1st hand experiance.

Dave T. it would be interesting to see where your cam marks are in relation to where the factory said they should be, ie; see if the factory cam marks lined up with marks on the attachment caps. Anyway Dave T. I'm glad you got the 355 back to good running order.

As to the idea of writing up a discription on this, Brian(rifledriver) and I think Dave Helms, tried and got such a load of crap trying to explain why a couple of years back, he gave up I don't blame him. The inexperianced on this board need to listen more and keep their comments to themselves. The tech questions on this forum should be answered by the handfull of guys that do this for a living and the rest of us need listen and learn. Regards, Vern

 

Well said, no doubt others feel differently!

 

Niki pulled apart a virgin 355 yesterday for belts. As soon as I can figure out this picture posting process I will show some pics for those that think it is OK to go the extra years on belt changes. The photos she took tell quite a story.
So much valuable information has been shared and in some cases fell on deaf ears over the years. Shame as there is so much extra money spent fixing these cars because of that. Properly repairing this new breed of "quick fixes" has become a full time job.
Remember the famous quote "If it blows up again, its no big deal" being used as an arguement a month or so back? With that mindset, I no longer waste my time defending doing things the right way as I got a bad rap for doing so.

Cchris0411, The marks Vern is refering to are the engine setup marks. They will tell you if you are within a tooth of the correct setting and assure you that you will not bend valves turning the engine over. Once aligned, time the cams as the factory intended. Get a shop manual if you are going in this deep on your own. Practice on a Honda, not a Ferrari.
As Brian said in the "exhaust burble" thread, we spent a full day at the factory dealing with cam timing for the dealer tech's that didnt know the procedure. Even at that, the factory taught the wrong way and was off in their settings.
Consumer acceptable is not a term that should enter into a conversation when discussing Ferrari.

Dave

 

Dave -

For posting pictures, I use this terrific little/free Microsoft Image Resizer application. You can "right-click" on any image file, and it'll resize it to an Fchat friendly 800x800.

Yes, there are much fancier tools in the world, but this one is simple and works perfectly fine for my needs:


The link is here:

http://www.microsoft.com/windowsxp/downloads/powertoys/xppowertoys.mspx

and the actual download application is here:

http://download.microsoft.com/download/whistler/Install/2/WXP/EN-US/ImageResizerPowertoySetup.exe

 

Dave H. or Brian, What is the smallest increment in degrees that the vernier pins on the cam pulleys will adjust to?

 

Simply moving the pin from one hole to the next is something on the order of 3 degrees.
By moving the pulley in relation to the belt in concert with selecting hole combinations will get you down to around 1 degree.
In practice the pins are usually just a little sloppy in the holes so infinite adjustment is possible.

With that adjustment system I have never been unable to set the timing ANYWHERE I wanted to set it. It is more time consuming than some systems but it works.

The 360 went to slotted holes.

 

Hey daniel, thanks for the info I needed it too, regards, vern

 

Why not just make a new thread titled "How to properly time cams"?

I have posted quite a few DIY threads, with step by step instructions, as have others. I don't see why it's such a big deal.

 

The unwillingness to check valve timing is strange, after all, porsche 911s have been using the vernier hole setup for ever, and it has to be set with measuring of valve lift. Nobody has questioned that......And as Brian says, you have a virtual infinite setting, any porsche guru will have his own personal set up for different cams/models.

 

Hi fellas, am curious on this point. Could somebody explain why the cams won't move at TDC ?

Is it because the valves would touch the piston or because somehow all 40 valve springs aginst the cam lobes balance out?

Thanks...

 

...and is this also true for a 550 engine?
Ron