Ferrari F355 Cam Lock Tool

So folks,

One of the guys that has the tools brought some issues up to me and I started doing some investigation. It's important to understand the benefits of the tool and the limitations as well as the theory and how it's to be used.

I've been working with Bruce (plugzit) as he was one of the few guys I knew with a motor getting ready to go back together as mine won't be getting assembled for some time. I also have another tech looking to do some testing for me.

Bruce has been a great champion and he has been texting me photos and we have been discussing the pros and cons.

I've asked Bruce to write up and honest review here stating his experiences and both the positive and negative points regarding these tools. So, please check back as Bruce will be doing so.

Thank you in advance Bruce for your help

 

I've now used Dave's tools installing the cams in the 355. I found it very useful in a couple of ways.
First, the tool provides an absolute lock of the gears for torqueing the bolts that hold the cam gears to the cams. I've had difficulty in this function in the past as I haven't found another satisfactory way to hold the gears in place while putting that much torque on the bolt. Torqueing against the belt seems wrong. Using a matchbook cover under the caps requires too much pressure against the caps for comfort too. Locking them against each other with vise grips could get ugly. Dave's tool allows me to positively lock the gears against each other. I did have to move the cams a few degrees to get the tool's pins into the teeth. It's easy enough to move the cams back into place, and even with the motor at TDC, there's no risk of valve-to-piston contact.
Second, the tool is useful when timing the cams. Using the backside of the tool, the gear is steadied in place while selecting the proper hole for the dowel pin.
Third, again using the backside of the tool, I could place enough pressure on the gears to keep the cams in place while installing the belt, yet still be able to move the cams a little to help seat the cogs on the belts (I think that'll make sense to those who have done it.)
In a perfect world, the tool wouldn't have to be removed at any time during the process, but the realities of installing belts and timing are such that any help is good help. This is an extremely helpful tool.

 

I like the idea of the tool holding the gears 'in place' (square to the seating surface of the cam) when rotating to align the desired dowel pin hole. That was always a bit unnerving to me.

 

I can see how the tool can lock cams to quickly tighten the cam bolts. Matchbook cover method is a tried and true method older than either of us. It works well and still what I do 30+ years later. But it is not fast. I would think a cam lock would speed the process. That is an advantage. Pros here say that you can torque against the belt. I use matchbook method. I don't know how to do the math but what pros say makes sense and then a cam lock tool would be extraneous. My thinking is 90ftlbs on the cam bolt is less that what the belt sees under normal operation. A cam belt lives in a violent environment. 8000 rpm, heavy pistons flying, 375hp, 200ft lbs of torque. But just like you feel uncomfortable with matchbooks I am uncomfortable with torquing against the belt. What we need is an engineer to do the math and decide whether the pros are right. If they are right then we are just being paranoid with no harm no foul being done just diy guys wasting time or money.


You will have to show me the other advantage you state. The camshaft snout have huge lands to retain the cogs. They do not need to be stabilized with anything else even during timing and cam cog pin removal.

 

But it should not be. The camshaft snout land holds the cog square. When cam timing you are only a few holes from perfect. I see technical issues with people who need more than fingers to pull cam cog pins or the same fingers to reposition a pin. Holding the cogs on place is done by an assembled belt.

Another advantage to this tool bruce did not mention is for those who lock and swap without cam timing but nobody does that right?

 

Bruce will be posting the photos later but using the tool with the belts on is challenging. The tool was designed based on the theoretical belt pitch and associated pulley relationship. With the belt tolerance and slack, it just does not fly without some intervention from the user by slacking the belt tension (you will understand when Bruce posts the pictures). I may re think this and work on another version to solve this issue.

Again, I first came up with this as my pulleys where on incredibly tight with a locking element (loctite perhaps) and I needed the tool to break the pulley bolts free.

It can be used to hold the pulley to tighten the bolts but you will see with the photos that it does take some finesse.

The tool is not the be all, end all. It has it's pros and cons and I'm not too proud to admit that. It's also fairly inexpensive so I feel the pros justify the cost.

In no way will I personally even use the cam caps with anything under them to hold the cams - break a cap and it's time for a new head. Now, we probably could make special caps for this purpose (as tools) but I still don't love that idea.

 

Again more math must be applied. Those caps retain a rocking 8000rpm motor 375hp few hundred torque. What is the force on hand tight caps over matchbook cover? Much much less is my guess. Don't forget how old this technique is and how universally it has been applied. I have never heard of one cap breaking or bending in over 30 years. "Ham fisted" should not be doing this anyway. Dumb people forget to take the matchbook out and destroy stuff but that is an issue for idiot proofing. It is unlikely that blunder could be made with your cam lock.

 

Well Bruce must be working on cars or drinking beer so I'll post the photos for him but I'll let him explain what he did
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Mine, while not as elegant as Dave's they do work to lock the cam while undoing/ torquing the pulley bolt.

Plus they were cheap, I made them out of bits and pieces laying around the shop.

http://www.ferrarichat.com/forum/139305367-post4.html

 

Dave, those are great - I love them and they are very elegant

 

You still have to mount the degree wheel and use dial indicators to set the cam timing. Hw does holding the cams solid in a questionable position help?

 

Again, the tool was mostly designed for lostening and tightening the pulley bolts. And, if you were the last person to degree the motor and you know it's correct, a lock and swap is all that's needed as you are starting off with a degreed motor.

 

Not true. The ferrari cam timing method is very precise. After proper cam timing and thousands of miles you will be one hole either way when you cam time 5 years from now. I proved that cam timing the 550 and also proved that factory scribed timing marks on the back of the heads are impossible to use accurately either. You will be very close however.

 

Sorry Carl, that makes no sense as belt stretch is insignificant.

 

Try it you will see.

 

I don't need to. A degreed motor with belts replaced is a degreed motor. The tolerance is not that precise. 1.5 degrees IIRC. People make far more out of this than it is. Many do such an inaccurate job of measuring the lifters and setting TDC, it's funny how belt stretch would even come into the discussion.

 

I'm struggling to understand a bit. If I degree the engine and make my marks on everything and the I degree the motor agin in a few years my marks won't be right? Do the lobes on the ams move?

I say in 5 years IF my marks line up I would lock it and swap belts. I wouldn't re degree an engine I've already done and marked.

If my marks were not lined up I would pull the belts line them up, lock it and put a new belt on.

 

Exactly Brian. The only variable is the belt and the stretch is insignificant.

 

I never said it was belt stretch either

 

While you struggle with that think about this. Ferrari tells you to degree the motor. If what you say is true and the factory timed the motor then every discussion we have ever had on fchat about cam timing is a waste of time because if we do as you say we would never loose the factory timing and there would be no reason to cam time a maintenance motor.

 

No, Ferrari does not tell you to degree a motor, they do explain the specifications, that is all. Please show me where they say to do so each belt change. The harsh truth is that makes no sense on a street car, OEM car based on the adjustment limits. I've always said I would degree a motor (or verify) what's been done by someone else. But if done correctly, no need to do it again when simply replacing belts.

 

If true then your camlock tool is of little use since there would be no need for its primary purpose to torque camshaft bolts. If everything stays perfect there is no reason to loosen camshaft bolts during a belt change.

 

Replacing cam seals requires the removal of the pulleys.

 

If we knew we could trust the factory marks then yes, it would be 100% a complete waist of time.

The only reason to degree a great running 355 engine on maintenance is that there is rumor that the factory timing marks are not always marked good so you may be off on reassembly. If I degree a motor and make my own marks I will go by those marks forever. I would NEVER redegree the engine unless I was changing a component.

Can you tell me the logic of redoing it? I'm serious, don't leave me struggling. What could change in the steal parts? Do the cams twist? Can the lobe centers change in relation to the area you have made your marks? What would make you ever doubt your own marks?

And yes, if you want to change cam seals, like most do, the pulleys are coming off.

 

I have always locked the cams, swapped belts, checked the cam timing and at least 1 or sometimes 2 of the four cams will need adjustment by 2-3 degrees. If that is good for you, then sure don't do the cam timing thing.

There are believers and non-believers of cam timing. One will never convince the other of switching camps. Tis your car, do what you believe.