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madmax

Cambelt tension query

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Whilst under my 82 Turbo trying to remove and reinstall the exhaust manifold, I notice last night that on the Long belt run from the exhaust cam to the bottom pulley that the belt is almost ‘baggy’ and far too loose. 

It feels ok on the short top run across the short gap between inlet and exhaust pulleys but it clearly been moving around enough to almost wear through the 90 degree hose coming off the water pump. 

Can this be adjusted in situ perhaps from underneath now I have the undertray off and if so, any pointers?

Thanks again 

Simon

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If that hose is a silicon replacement unit - they are typically a very poor fit replacement for the Lotus rubber ones.

grab and twist the belt - typical twist is between 45-90degrees

i won’t start mentioning cricket or phone microphone tension methods as that will degenerate into a whole myriad of bluster

Yes you can adjust in situ. Once you’ve done that - turn the engine over by hand as the tension will alter

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Look for a flanged bolt head on the tensioner and tighten which will push the black piston onto the tensioner assembly and tighten the belt. This is the tensioner. 

20180215_114501.jpg

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Thanks guys

I’m familiar with it on my Elite but access on the Esprit is not something it’s kbown for  

The bottom hose is a rubber one but close to being worn through so SJ will no doubt have to come to the rescue  

Not sure how I make sure I describe the correct one but it does appear to come from the water pump  

When we talk about the twist in the belt, will it not twist far more readily on that long run than elsewhere and will tha tensioner take up slack in that long run as it sits round the bottom pulley, away from that long run  

It’s good to run these things past people - I don’t feel like I’m making critical decisions on my own 

Thanks

 

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Yes, the long run of belt will twist far more easily than the short run. Also, the engine will have stopped in an random part of the cycle so you can end up with additional tension in the long run, or additional slack in the long run, as compared to the normal you'd experience when at TDC. The reason being that the cam lobes will cause the tension in certain sections to increase or decrease depending on whether the cam is just about to fully open a valve (and so resisting the spring force) or just starting starting to allow a valve to close, so the spring is forcing in the direction of belt travel. The slightly aged belt will have stretched, but that's fine.

Don't worry about the tension in the long run, just concentrate on what's in the short run used for tension checks, and then only when at TDC on a newish belt (or allow for reduced tension on an aged belt).

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Not familiar with the TE but are you talking about the water hose which connects to the aluminium pipe that runs through the chassis? If so, check that the ali pipe hasn't been pushed backwards, putting the hose in harms way. I had this happen resulting in a lot of steam when the cambelt sliced through and all it needed was to replace the hose and push the pipe an inch forward and clamp it in place to get it just out of reach of the cambelt. It's still a very close gap between the two.

Pete

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I had exactly the same happening. The original rubber bent  hose was half worn by the belt. I changed it by a new rubber one from SJ. When I compared the two hoses , I could see that the old one had bulged from age and that caused it to  come too close to the tension belt. The new one does sit a lot better.

And yes, The belt can be slack at that end. It is important to overhaul the automatic tensioner AND to use new springs in it . SJ does sell these too.

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