Cam locks - 1 dumb ? a year allowed.

one set works fine... there are two sets of belts. they are not connected.

 

+1. Yes, you can do one at a time.

 

Actually the belts are connected because both belts connect to the crankshaft. The idea of the clamp is that both of the cam shafts are locked so that they cannot move independent of each other. The other thing is that the crankshaft cannot move independent of the camshafts either. The clamp only im-mobilizes the camshafts. The crankshaft is harder to rotate so there is no lock on it during the process. You have to ensure that you do not move it during the changing of the belts. If that happens, then the valves will not open or close on time and the damage from that would likely be catastrophic. The valves may hit the pistons if the timing is off enough.

To summerize, make sure the cams do not rotate. Make sure the crankshaft does not rotate.

If they do move, there is a procedure for making it right again. There's marks on each of the pulleys and they have to be lined up. That is all that I know about timing the camshafts. I did it many years ago on American V8's, but that is a little different game than this and the engine was out of the car.

 

Robert- Those marks are assembly marks to aid in the assembly of the engine. To correctly time the engine, you need to find true Top Dead Center (piston stops are good for this) and then use a degree wheel and dial gauge to get the cam timing correct. Doing a "lock and swap" using the assembly marks will cost you a lot of horsepower. Do a search here on degreeing cams for the correct procedure.

Taz
Terry Phillips

 

With a suggested 3 year belt replacement intervals, is anybody really going to pull cam covers every three years? Get real.
I've done three belt replacements since the valves were last adjusted. That adjustment was less than 3k miles ago.

 

Ok, it is best to lock all 4 cams at one time, but 2 at a time is possible.

As to factory marks on the cams vs. "degreeing" the engine for timing, I wonder if anyone would really notice the difference. Maybe on a dynamometer. (This should spark some controversy)

 

Yes, you can definitely do one belt at a time. Maybe this photo will help to show you why. One belt isn't behind the other -Steve
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No one has mentioned taking the spark plugs out so the engine is easier to turn over. Perhaps it's so obvious. I generally put tranny in 5th gear and place a flat steel bar between wheel studs. Stepping on it easily turns the engine over with both rear wheels off the ground. I don't have a socket large enough for the nut on the end of the crank pulley so this is my technique.

 

Glassman- Setting valve clearances and degreeing camshafts are two different operations, unless you meant both require removing the cam covers, which you are loathe to do for belt changes. For degreeing the cams, Ferrari recommends temporarily adjusting one valve for each cam to 0.50 mm to adjust cam timing.

Your car. Lock and swap belt changes will not damage the engine because the assembly marks are there to ensure that does not happen. You might ask Brian Crall or Dave Helms how it affects performance. They have commented on it so often, however, they might not wish to do so again.

Taz
Terry Phillips

 

For the 3X8 owers that want to spend the money to degree the cams (there are not many) I only do it every third service if the top end is dry and there is no reason to remove the cam covers. In our partial year driving season here and back in Minneapolis, the cars never got enough miles on them to warrant pulling a well sealed cover to adjust the valves at each belt change. That is not the case in a warm cliumate where the cars are used year around and is the reason that some logic must be applied when servicing these cars unless cost is no object...those days are long gone.

Some 10-14 years ago we never had leaking problems at thecam cover, cam seal or the housing o-ring, that isnt the case these days and is something we are currently studying. We can no longer get 2 or 3 services done with the top end remaining leak free unless the everything is gobbed up with sealant. One of the reasons we are now seeing so many bottom end failures with the oil pick ups plugged with silicone worms. Now that I am in the rubber molding business (yeh, really fun stuff!) we are working with new designs and ideas to eliminate those problems.

One thing I read about in so many threads these days is this 'cam lock' thing and that I am totally lost on...interesting how trends go through this hobby of ours over the decades. I AM on the other hand happy to finally see folks talking about cam timing, that was a hard trend to get started and we were beaten senseless getting the idea to stick. Looks like good came from that in the end.

 

A question Dave.....
How can the degreeing of the cams change from one belt to another?
I always thought the degreeing option was for initial assembly and that's it.
Enlighten me......thanks.....Larry

 

Dave- Thanks for the information. Always learn something from you. I remember Brian saying you did not need a major every time you changed belts. Now I know what he meant.

Makes me fell better about my lock and swap in spring 08 before I got my car. Bobileff did it, so I know it was done correctly. Guess I am good to 2013 unless I get a leak.

Glassman- Looks like you got it right and I got it wrong.

Taz
Terry Phillips

 

My two cents which nobody has mentioned:

Using cam locks on both banks, helps keep the crank from wiggling when changing the other belt.

Jay

 

At one time, I owned an Acura NSX. To hold the cams, the factory drilled a vertical hole in each cam, and holes in the cylinder head. All I had to do was slide the correct size drill bit in. Too bad Ferrari didn't do that. -Steve

 

The concept of the Cam Lock is really for us doofus DIY mechanics. This way we can be pretty sure we havent screwed anything up when swapping belts only. I am assuming the pro's mark the position of the cams and drive, and if they move during removal they simply turn them back where they were before. Thats too scary for me!!!!

 

Ferrari did that for adjustment of the clutch linkage....in the 70s.

I would hate to be the owner of the car where the mechanic forgot to take the broken drill bit out.

 

I would never claim being a 'pro', but I did it that way all the time. Never had a problem. I even move the cams a little bit - a tiny bit -, so that it's easier to slip the new belt onto the pulleys. I also don't have to hold the cams in position. Like Verell said - the 2V cams seem to be less problematic. When done - like you say - I just turn the pulleys back to their correct position with the help of the markings.

Best Regards from Germany

Martin

 

I have had the opposite experience. As the cars have gotten newer and the sealants better I have had less leaking than in my 308 days. Hondabond and yamabond have provided me with the most leak free cases in the last 5 years. I always hated silicone for the exact reason you posted. No matter what you did you always got worms. Bruno in L.A. used to be the king of silicone but I don't think he had anymore engine failures than anyone else. Maybe if you used a Bruno amount of silicone the mass was so large it would not break off and plug engines. I used hylomar for many years out of fear of the silicone worm. That stuff was just crap in my hands. It always leaked.

 

Blasphemy! Blasphemy!

LOL!!!!

 

Ernie- What do I know? I do not even have a dial gauge or a piston stop. I just read a lot and have lots of tech data. I even gave my Dino/Daytona/308 valve clearance adjusting tool to my techs today when I picked up the 575M.

But I do believe in the New Testament as preached by Brian Crall, Dave Helms, Steve Magnusson, and a few others.

Taz
Terry Phillips