timing belt one tooth shifted (see a simple tool)

[renckensj2]

When I replaced the clutch of my Esprit I discovered that the timing marks on the camshaft pulleys were not correctly aligned. There was a shift of one tooth! Fortunately the pistons did not touch the valves and there is no damage at all. After all it is very difficult to see without a tool whether the dots on the camshaft pulleys are correctly alligned: on the picture it looks correct but it is not:

I made a simple and cheap tool to check whether the timing marks are facing towards each other. I just used a plastic CD-cover which I cut in a T-form ( see picture) and I put a line at 19 mm showing the connection line of the centers of the 2 camshafts.

On the next picture one can see that the 2 dots are not positioned on the centerline, however there is not much deviation.

When we turn the engine a little bit, such that one timing mark fals on the centerline of the tool, one can see very clear that the IN and OUT camshafts are one tooth shifted.

After the correction of the time belt, I could not feel a difference in performance.

I hope that this easy tool can help all of you with the positioning of the timing marks.

Regards

Jos

[rudolphwolven]

Jos,

Interesting.............very good idea.................!!!

Best regards,

Ruud

[Paula&Marcus]

Hi,

According to the pics your exhaust pulley was one tooth off. This is not correct, of course, but wont make too much difference nor problems. Fortunately it was not the intake one !!!!! With the intake one, one tooth off you would definitely feel the difference.

Cheers

Marcus

Edited February 14, 2008 by Paula&Marcus

[rudolphwolven]

Hi,

According to the pics your exhaust pulley was one tooth off. This is not correct, of course, but wont make too much difference nor problems. Fortunately it was not the intake one !!!!! With the intake one, one tooth off you would definitely feel the difference.

Cheers

Marcus

Hi Marcus,

I am interested to know:

"Ref. intake one tooth off": ........feel difference in horsepower or valves hit pistons.....?

If hitting pistons.........is this controlled in such a "sharp" way....?

Best regards,

Ruud

[ragingfool35]

how do u know which pulley was out without seeing the crankshaft pulley alignment marks?

Edited February 15, 2008 by ragingfool35

[Paula&Marcus]

Ruud,

With only one tooth off it wont hit the piston, but will run not smooth ...

BTW, the Lotus engine is not "cammy" at all. It has a lift (around 10mm) with an open duration only 250

[iainskea]

Nice tool there.

To add some complexity though, if the head non-flame faces or cam blocks have been skimmed then the pulley alignment will have progressed slightly due to the decreased geometry. Therefore, as Marcus implies, some thought needs to be applied to any misalignment to ensure the timing still runs true.

Making sense?

Iain

[renckensj2]

how do u know which pulley was out without seeing the crankshaft pulley alignment marks?

I made also a photo of the flywheel, which was very accessible since the bootfloor was removed because of the clutch replacement. Here it is:

[rudolphwolven]

Ruud,

With only one tooth off it wont hit the piston, but will run not smooth ...

BTW, the Lotus engine is not "cammy" at all. It has a lift (around 10mm) with an open duration only 250

[semi42]

my 79 s2 has the cam marks on the other side of the sprockets and making a similar tool, i found that the exhaust sprocket is off too. intend to replace the cam belt this winter and hats off to shb662. I have been getting a niggly misfire on the rear cyl hopefully this will clear it up. incidentally, there are also line popped marks on the sprocket teeth that dont line up with anything...what are they for?