QUESTION
I recently purchased a timing belt and the part number A907E0191Z indicates it is for a normally aspirated 907 engine.
My 1985 Esprit is turbo-charged and has a 910 type engine
Is the timing belt that has been supplied correct for my engine?
There is an arrow on the belt, should it be pointing towards the engine or away from the engine?
Also does a new belt require more tension will it stretch being new?
D.R. - Brookvale, NSW
ANSWER
With early engines up to 1987 (including 907 and 910) they all used the same square tooth timing belt, Lotus part number A907E0191Z.
In practice, the timing belt can be put on either way round.
However if the belt is removed in the near future (say for tappet adjustment) then it must be reinstalled the same way it was removed so the arrow is a useful reference.
This is because the belt is only driven from one side and it establishes a directional wear pattern.
A 1985 manufactured Esprit is usually fitted with an automatic belt tensioner mechanism that is operated by a dual spring assembly.
From experience, the springs do fatigue with age/use and the belt tension does gradually reduce over time.
With this in mind, the timing belt needs to be installed at the correct tension and must be checked with a Burroughs gauge - see the Lotus Service Notes.
Copyright © 2016 Lotus Marques
I recently purchased a timing belt and the part number A907E0191Z indicates it is for a normally aspirated 907 engine.
My 1985 Esprit is turbo-charged and has a 910 type engine
Is the timing belt that has been supplied correct for my engine?
There is an arrow on the belt, should it be pointing towards the engine or away from the engine?
Also does a new belt require more tension will it stretch being new?
D.R. - Brookvale, NSW
ANSWER
With early engines up to 1987 (including 907 and 910) they all used the same square tooth timing belt, Lotus part number A907E0191Z.
In practice, the timing belt can be put on either way round.
However if the belt is removed in the near future (say for tappet adjustment) then it must be reinstalled the same way it was removed so the arrow is a useful reference.
This is because the belt is only driven from one side and it establishes a directional wear pattern.
A 1985 manufactured Esprit is usually fitted with an automatic belt tensioner mechanism that is operated by a dual spring assembly.
From experience, the springs do fatigue with age/use and the belt tension does gradually reduce over time.
With this in mind, the timing belt needs to be installed at the correct tension and must be checked with a Burroughs gauge - see the Lotus Service Notes.
Copyright © 2016 Lotus Marques