36 replies to this topic

[Steve220]

Hi all, bit of a strange one. After Moke mentioned about putting a few degrees of timing in to help with the chain stretch as the engine wears in, i went to play with mine. Something a noticed that I hadnt before is the crank pulley sits more proud than the camshaft pulley on the duplex. Ill get the exact distances but it looks like around 1mm! Any advice?

[nicklouse]

any shims under the crank pulley? is it seated fully?

[alex-95]

As above are you sure there isn't any shims under the crank pulley? I cleaned mine, got it ground and balanced and didn't notice them until my crank pulley was sticking out a little. What make of chain/gears is it?

[carbon]

Also has the timing cover backplate been replaced by an aftermarket (alloy) version? Some of these are thinner than the factory original backplate.

 

Thinner backplate has the effect of moving the cam drive pulley towards the flywheel end, while the crank pulley is not affected by backplate thickness.

[Spider]

Just check too that the Cam is up against the thrust plate.

[Steve220]

Crank is reconditioned, zero shims on the crank and new triangular plate. Turned it over about 10 times and its now straight!

[nicklouse]

so what moved? crank pulley not seated? 

[carbon]

Steve,

 

Worth checking the camshaft end float

[Steve220]

Crank pulley has always been torqued up. I think the cam has moved. Does the camshaft float measure the movement of the camshaft against the triangular piece? Ie its trapped between the camshaft and its sprocket?

[carbon]

Yes, camshaft end float is essentially the clearance between the triangular plate and the faces of the cam and cam pulley.

 

Clearance (ie camshaft end float) should be between 3 and 7 thou

[Steve220]

Ok, will go check it

[Steve220]

Its 0.11mm/0.0043

[Retroman]

Check the end float on the crank too, looks like the cam is ok.

 

Something has moved significantly...turning over by hand will not fix pulleys out by so much.

 

You say the crank pulley has always been torqued up...its not even fitted..?

[Steve220]

Retroman, i refit it and did a visual check after the photo. The crank float was nicely within tolerance, probably on the tighter side of it too.

Just measured the distance between the chain (once pushed home on the sprocket and tappet gently with a rubber hammer) and the backplate. The difference is 0.2mm/0.0078, the crank was the proudest measurement.

Edited by Steve220, 10 March 2018 - 08:06 PM.

[Retroman]

Not sure how that works accurately, can't understand "the crank was the proudest measurement"..??

 

What did you measure the gap with?

 

End float should ideally be measured on the crank with a dial gauge, 0.002 to 0.004" is the aim

 

So if it is 0.078" its way off