Timing belt hanging over tensioner

I just installed new timing belts on my 78 308. The rear belt looks fine. However, while looking things over I noticed the front (5-8) belt is hanging over the tensioner slightly. By slightly I mean like 1/16" or so. is this okay?


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Install error. Without tension belts need to be fully installed on cams and tensioner with cams straight up on marks and #1 piston at TDC. Then tension belt. Then rotate motor in driven direction until you are back to #1 piston at TDC. Everything should look perfect and the motor spin easily and freely when doing this. 308 run best if cam timed but work just fine on assembly marks.

 

Thanks, I agree. But where was the error?

I installed the belts without tension. In fact, I would say it is impossible to install them unless the tensioner is fully compressed. The #1 piston was at TDC. All the cams were on the factory marks. The motor spins easily. And, in the picture, it is clear the belt is fully installed on the cams.

 

Why is your exhaust cam pully so much further forward than the intake? At least thats how it looks in the photo. Could be a perspective thing, but looking at the stud, it looks to be not seated properly on the cam snout..

 

Thanks for the posts and private messages.

The good news is that after a few engine rotations the belt is back on the tensioner. This happened getting the engine back to TDC.

The bad news is I still have to take the whole thing apart. I discovered this morning that the exhaust pulley lip is cracked. It's not completely broken but I can pull the lip a little bit away. I would not want to roll down the road with it. Now I have to go find a pulley. I'll check everything carefully when I reassemble.


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I have replaced the pullies before with billet aluminum pullies offered from a respectable supplier. I had the center bolt leak oil from both cams on one bank. I finally found the aluminum was slightly thicker and didn't allow the o ring to crush properly. I ended up using two o rings stacked and this stopped the leak. Just be aware of the possible issue if you use aftermarket. I have used them more than once and only had the one issue. Just check it so you don't have to go back in a second time.

 

Thanks, but I am not following. Probably me. I do not recall any "leak" in this area. The pictures are showing the timing belts which are outside of a fluid area.

 

I am trying to find a replacement pulley.

First outfit (which I trust) is asking me if my pulley is plastic or steel.

Mine is plastic.

My ignorance. Why is the vendor asking plastic or steel? Is it bad to mix and match?

 

I'm guessing so they give you the correct one. Ferrari loves to change things mid year...If I remember correctly though, Hill engineering makes an uprated set of those. You'd be well advised to look into them before buying another Ferrari part

 

Seen that many times, if these cars still have the plastic pulleys we toss them for aluminum.

 

You will probably hate to hear that, but when the lip of one of my pulleys cracked while doing a belt change I replaced all four. Because I expected the other three following soon with less luck and perhaps cracking while the engine runs. I purchased original Ferrari steel pulleys back then in 1998, because no aftermarket alternatives were available. They were big $$$$$$$ and the biggest challenge was timing while fiddling with the three holes for the pin. I wished, there were alternatives with five or more holes on the market, like available today.
Or even seamlessly variable oblong holes. (In which I don't trust)

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Best from Germany
Martin

 

I have been wondering about the timing. If I just use the factory (assembly) marks on the cam it doesn't matter, correct?

I know the "right" thing to do is set the timing with a degree wheel. But it's been running great just using the factory marks.

 

Yes, the timing marks on the cams are sufficient. But you will struggle anyway, because your replacements you will get are not, and cannot be exactly identical regarding the radial position of the holes for the pin. In relation to the belt tooth pitch.
My fight took a whole working day (8hrs.). Maybe experienced pros are faster, but I regard this job as a major pain in the arse.

BTW. I just looked into my records and compared the costs from 1998 for my steel pulleys with the damned three holes with the current price from Ferrari UK (Maranello Conc.) While I thought, the 1.600.00 DM for the set of four (former Deutschmark, now around € 800.00) were expensive, now the price did skyrocket. 312.00 GBP plus VAT / pc.
I would have a closer look on the set from Superformance. Their set of four is around GBP 500.00 +Vat and they also have five holes. I have no experiences regarding wear of the aluminium though. But it's not so wear-resistant one might think. It's not much better than the GRP they used for the plastic ones.
Maybe there are others here, who have long-term experience regarding the wear of the aluminium pulleys.

Best from Germany
Martin

 

Just my opinion.....My 308 GTS has the plastic ones, my GT4 has the steel. I want to replace those plastic ones at the next service because they have visible wear, and I have seen those gear fences crack off on another 308.

This was decades ago, and we bought replacement from the dealer. The replacement part was steel, and ~ $300 ++ for that one gear. We had the engine out, so that was much easier to access to set up timing etc. Looking back, I kind of wish we would have replaced the whole set (12-1600 $$). It was a buddies car, and he wanted to pump the brakes on replacing if the other gears were functional. We looked them over pretty carefully and pulled on the fences and didn't see any signs of failure so it was just the one. Maybe Eurospares has a good set of used steel gears??

 

I gave up on a used one after searching for several weeks. My main source for used parts never came through. So I am going with the Superformance set. Supposed to arrive next week.

For sure I am not going to put the air gun on that pulley installed in the car. I tend to think it would be fine. On the other hand, something could go wrong .

So... I need to "hold" the camshaft while breaking loose the bolts holding the pulley with the air gun.
And... I need to install the new pulley and presumably torque the bolts - or maybe they just need to be snug - I don't know.

Tips on removing the old pulley and installing a new one?

 

Air gun is least traumatic but you need to lock cam from moving. Matchbook cover is the way but if you have to ask....skip the airgun and just match book and use a torque wrench. If you are well over the install torque upon removal, stop and report back here for next step.

 

BTDT.

Those cam end pulley bolts are TIGHT. I doubt that you will be successful in removing them without potential damage while the cam is in situ on the head.

Better to plan now on removing each cam and holding it in a vice while you hit them with the biggest air gun you can find.

DM

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