Cam belt position on pulleys.

Did the 328-cambelts last week. Finished work and used the starter for a few seconds (without fuelpump) to check the belts.
The belt on the left bank travels midways over the cam pulleys. Seems okay to me.
The right bank belt rides the inner pulley side. This confuses me al little.
The lower pulley bearings are fine, without play or oil leaks.
New tensioner bearings are installed.

Is it okay to start the engine?

 

I would....but I'm just some goofball hiding in a small garage somewhere in Montana.

 

Are the new belts in the position of the old ones, riding the same track on the pulleys? Do the belts move back and forth on the pulleys? You can easily turn the engine over by hand using a large socket on the crank shaft nut. That way you can watch how the belts ride while turning the engine over by hand.

I wouldn't start it unless you are really sure the belts are positioned correctly and won't ride off the pulleys.

 

In my opinion the tensioners steer the belt direction over the cam pulleys. They are the last guide before pulley entry. So one of the new bearings must be slightly misaligned.
Maybe Ferrari technicians use shims to correct minor misalignments caused by the tensioners?? I don't know.

If the misalignment continues I will try the following:

- Reverse the bearing on its axle.
No result:
- Take the belt off and install it backwards.

In the forum 308/328 there is a picture taken showing belt change. One of the belts pictured rides the outher side of the pulley also. So it must be a common "failure".
A Dino GT4 belonging to a friend shows the same misalignment: the belts on both banks ride the outer sides. Only opposite, to the wheel side.

 

Interesting point. I use the Hill Engineering bearings with a single race. If you used the SKF double race bearing, perhaps it didn't seat all the way. However, I have a difficult time understanding how that could happen.

In the procedure, you are to turn the engine by hand 2 full revolutions and then torque the tensioner bolt to fix it in place. Did you do it that way? Maybe before taking things apart, loosen the tensioner bolt that locks it in place and rotate the engine 2 full revolutions to see if the belts move into a better position. If not, you didn't lose much time.

 

I would say that after turning the engine with the starter as the OP states, the belts are where they are going to go. If it is worrisome at this point checking the tensioner bearing by removing and resetting is probably a good idea.

 

Ok, thanks for the responses!

The present situation shows the belt about 0,5 mm too far out.
And yes, for the first time I use the single race Hill bearings. Last time it was SKF double race.
So, different parts.
The other (left) belt is leaning against the opposite pulley side.
It looks like both belts are steered by the protective sidewalls. Preventing them to ride off.
In my opinion this is not a very comfortable situation.
What I like to see is belts not touching any pulley side.

I wonder if shims are used to compensate the belt path.

In the old situation the right belt was riding about 1 mm inwards the bearing surface.
Tomorrow I take the cover off and have a look.

 

This is the situation.
Would it give you peace of mind? I'm not comfortable with this.
The belt rides 0.5 mm outside the pulleys.

Johnny thanks. This week I try to slacken the tensioner, give two revolutions and see the result.
Glassman, the bearing removal and resetting comes next.
If this situation continues maybe tilting the tensioner by adding a small spacer would help.
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Tilting the tensioner by packing it out is asking for trouble. Reset the belts so they are closer to the fence...

 

I agree with this. Try and reposition the belts so they are in the middle of the cam pulleys. They are wide enough that I don't think they will "walk". If they do, I would get the car to a professional and let them troubleshoot it.

 

I'm no pro but I can tell you this idea is insanity.

 

Okay, this might be a good idea. Probably belts stay in place at the spot of installation.
What wonders me; the left belt walks (or stays) to the opposite side (not on photo).

So, could it be that I swapped the tensioners in 2003 when a overhaul took place?
They are interchangable. Maybe they are machined (matched) to each bank?

This because of different belt behaviour left and right.

 

I know, but what I mean is adding approx 0.1 mm spacer behind the assemby and block. By doing this the bearing would point slightly outwards, steering the belt back on track.
Just brainstorming

The only thing happening would be the belt slighty turning on its axle before entering the cam pulley. Not harmfull in my opinion.

 

You've been warned, knock yourself out.

 

Well, I believe you.
Tomorrow at first slacken the tensioner. Slide the belt into the desired position. Two revolutions. Tension back on.
Cranking, no fuel, no ignition.

Option two.
Bearing out. Backwards installation.
Same procedure.

Option three.
Reverse belt direction.

Four.
Swapping tensioners left and right.

Thats the plan. No spacers. Okay okay okay

 

Calling RifleDriver .........

 

Take out the plugs and turn it over by hand ... 4-12 times is usually enough to show any misalignment.

 

Its simple. If the belts do not run true at least one of the arises is not true.

All must be perfectly parallel.

 

And you'd be right. Simple problem with an even simpler solution...

 

No, please not Rifledriver
I know what wil happen. He is already crying reading this 1.000.0000.0000-st thread involving cambelts. Worst: problem is caused by amateuristic behaviour. Not his game at all.

Problem solved thanks to you guys!
I followed your advice to slacken the tensioner, give two revolutions. At the same time pulling the belt into pulley centre. More revolutions: belt stays put.

Belt tension. The Ferrari/Verell method. Tensioner loose. Find the tightest spot in the longest part. Easy, because it feels like a string at some point (about TDC right belt). Fasten tensioner. Ready!

My lesson: installing a new belt, centre it manually. It won't find the pulley centre by itself!
Tomorrow the same treatment for the left belt.

Thanks !
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Excellent! Happy driving!

 

Some new knowledge:

On high mileage V-8 the lower drive pulleys suffer on surface wear. This can result in "slope" effect causing the belts to wander sidewards.