Cam belt tensioner question

[Grenouille 4 1 Cars]

I am changing the cam belt (113 tooth and spring style tensioner) on our 1991 1.6 XU engine and have a question on tensioning the belt; the Haynes manual states that the belt needs to be tensioned, the engine ran and then re-tensioned.

 

However, I cannot see any way of increasing the tension generated by the tensioner spring, (other than forcing the tensioner across mechanically and clamping it down at that place) nor why you would need to; surely that’s the design?

 

Currently the belt is fairly easy to twist by 90 degrees on the longest section between the crank and cam sprockets. 

 

I haven’t replaced the spring as it didn’t come with the kit, but I guess that could be stretched. 

 

A steer on this would be appreciated. 

 

Oh and if anyone has any good ideas on how to torque the crank pulley bolt whilst the engine is in a stand with no flywheel, I’d appreciate it. I don’t fancy using the timing holes to lock it. 

 

 

 

[DamirGTI 323]

Spring type tensioner by design is made to tension the belt automatically , but can increase/add some additional tension manually if needed .

 

If you got the sump off jam the crankshaft with an piece of wood or similar .. or can feed some rope in one cylinder trough spark plug hole and jam/lock the engine that way .

 

 

D

[Roeland_Vester 5]

On 2/14/2019 at 1:21 PM, Grenouille said:

Oh and if anyone has any good ideas on how to torque the crank pulley bolt whilst the engine is in a stand with no flywheel, I’d appreciate it. I don’t fancy using the timing holes to lock it. 

Mount the flywheel and use a locking block? You can make one from a small piece of scrap wood easily, just use the gearbox bolt hole to hold it in place, and file a few negative starter ring teeth in the wood. The diameter of the flywheel ensures that the shear force on the wood stays low.

Edited February 16, 2019 by Roeland_Vester

[Telf 222 2 Cars]

Whenever I set mine I just got the belt and manually crank the engine round a few times. When the longest section feels at its tightest in terms of twist/deflection I lock the tensioner in the manner described in the Haynes. You can quickly get a feel for it being tight after a few turns of the engine. This method works fine for me

[Grenouille 4 1 Cars]

Thanks all for the help. I think I'll rotate the cambelt as you suggest Telf and then loosen and retighten the nuts; seems sensible.

 

As for tightening the pulley, I've sealed up the sump so loathe to take it off again. I think I'll take the engine off the stand and mount the flywheel. I can't see much else that can be done. Just means I have to manhandle the engine sooner rather than later...

[Roeland_Vester 5]

If you can wait to start your engine until it's in the car, it's also possible to tighten the pulley bolt by putting the car in gear, applying the brakes and torqueing the bolt. You need to remove the inner wheel well cover to do so.

[tartanbloke 35 1 Cars]

Evening,

 

A 10mm socket placed within the recess of the pulley over the 10mm bolt locks it in place so you can tighten it up. I have done this on three cambelt replacements without any issue. Happy to supply photos if needed.

 

 

[Grenouille 4 1 Cars]

On ‎2‎/‎24‎/‎2019 at 9:05 PM, tartanbloke said:

Evening,

 

A 10mm socket placed within the recess of the pulley over the 10mm bolt locks it in place so you can tighten it up. I have done this on three cambelt replacements without any issue. Happy to supply photos if needed.

 

 

Hi Christopher,

 

I'm away with work at the moment so can't look at my engine at the moment, so forgive me if I've misunderstood. Isn't there a risk still that I could crack the block 'mouldings'?

 

Thanks,

 

Andy.

[Tom Fenton 1,524]

Personally I'd just wait until its off the stand and lock it with a pry bar in the starter ring gear on the flywheel. Use Loctite on the crank bolt and ensure you torque it to spec.

[Grenouille 4 1 Cars]

Agreed Tom, I think this would be best. Just need to remember to do it!

 

Thanks again.