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Timing belt a tooth out on cam sprockets?


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I always lose complete confidence in myself when doing timing belt so could someone just sense check me please?

 

Got old belt off and new one starting to go back on although I'm getting a new auto tensioner rebuild kit (which may cure this worry I have). Got the belt around cam sprockets (aligned), ignition sprocket, and crank sprocket with crank at TDC but there seems to be a little too much belt slackness between cams for my liking. The problem is it's not a tooth worth of slack.

Once the tensioner is back on and engine turned by hand, will this tighten up and sort itself out or am I possibly a tooth off somewhere?

Done this so many times on cars but always makes me nervous so please be kind! 😁

https://youtu.be/xrAWgPsG2e4

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  • Gold FFM

It's hard to see in the picture but the clip does show quite a bit of slack. The exhaust cam could be one tooth out, assuming it can rotate half a tooth when the belt is tensioned. You could put a spanner to the exhaust cam to rotate it and tighten the belt, that will give you proof one way or the other.

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I have made many mistakes in my life. Buying a multiple Lotus is not one of them.

 

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  • Gold FFM

I think it's clear to all that what we need here is a set of clearly marked timing dimples and a decent picture of them.  Anything else is pointless.

British Fart to Florida, Nude to New York, Dunce to Denmark, Numpty to Newfoundland.  And Shitfaced Silly Sod to Sweden.

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Ok I need some advice from the good people on here regarding the cam belt for the Elite.  
The cam belt I was told that was correct was a Gates 5146, which I have fitted. The car runs , but it’s not road ready, so engine hasn’t been pushed. 
Soldave has started this post , and I now have doubts whether it’s the correct one , regarding belt width.  The 5146 fits but is 25.4mm wide, the cam wheel is 30mm. 
Is there a belt that is a perfect fit ?

What spec. are you fitting Soldave ?

Tony 

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  • Gold FFM

5146 is the correct belt.

Dimples, when closest to each other (unless head has been massively skimmed) will result in a fairly tight fit of belt teeth between the sprockets, without all the slack you've demonstrated.  It's that simple.

British Fart to Florida, Nude to New York, Dunce to Denmark, Numpty to Newfoundland.  And Shitfaced Silly Sod to Sweden.

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  • Gold FFM
11 hours ago, Chillidoggy said:

Well, if they’re lined up why are we having this discussion?

Because they're lined up with a slack belt. Once it is tensioned, they will move out of alignment as the exhaust cam rotates to take the slack. I found it easiest to turn the exhaust cam back just a bit, enough to be able to easily fit the belt. When tightened the belt again both cams should align.

I have made many mistakes in my life. Buying a multiple Lotus is not one of them.

 

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23 hours ago, Chillidoggy said:

Surely, if they’re lined up with a slack belt, they’re not lined up? A decent photo would be nice.

The little youtube clip gives a better view of things. But I agree, problem and solution have clearly been identified. In the end you can only be sure after everything has been properly tensioned and the engine turned at least 2 revolutions by hand.

I have made many mistakes in my life. Buying a multiple Lotus is not one of them.

 

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Unless I am mistaken, there are not dimples in the cam pulleys, but there are marks akin to divots on the inner edge of both pulleys. These appear to be aligned in the top photo. 1 divot beside the tooth underneath 'IN' on the LHS pulley and the other lined up with the 'X' on the RHS pulley.

I have coloured dimples in the outer edge of both of my pulleys as well and not marks like these.

I recall being concerned about my alignment and went through a bunch of checking once I had tensioned everything up. It all turned out ok.

All we know is that when they stop making this, we will be properly, properly sad.Jeremy Clarkson on the Esprit.

Opinions are like armpits. Everyone has them, some just stink more than others.

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