36 replies to this topic

[Steve220]

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

Seems to be confusion here. The facts:

- On first view the crank sprocket appears to sit more proud than the camshaft. The photo was taken prior to tightening it all down although had been pushed back with a socket as a drift.

- There are no shims between the crank and the sprocket.

- The crank end float was within tolerance at the time of installing, it was actually on the tighter end of the tolerances. The clutch and flywheel is currently fitted.

- The camshaft has a 0.11mm/0.0043" float, so within tolerance (new cam, new back plate, new triangular piece installed with the build).

- After running the crank over around 10 times i re-did a line of sight check then measured the distance between the chains outer face and the back plate. The distance at the crank sprocket to the back plate was 24.00mm and at the cam sprocket it was 23.80mm. Measured with digital verniers.

Edited by Steve220, 10 March 2018 - 09:16 PM.

[Retroman]

Ok Steve thanks for the clarification I have added my comments in italics

- On first view the crank sprocket appears to sit more proud than the camshaft. The photo was taken prior to tightening it all down although had been pushed back with a socket as a drift.

   Having thought about the photo I think it could just be the chain deceiving all of us, and now its been turned over a few times now it has settled to a more central place. The sprockets can't be seen well on the photo.

 

- The crank end float was within tolerance at the time of installing, it was actually on the tighter end of the tolerances.

How was it measured?, and how much float was there ?

 

- After running the crank over around 10 times i re-did a line of sight check then measured the distance between the chains outer face and the back plate. As above.

The distance at the crank sprocket to the back plate was 24.00mm and at the cam sprocket it was 23.80mm. Measured with digital verniers.

  Ok so you have measured the crank sprocket and cam sprocket, that will give you an idea of how well the chain sprockets are lined up, and has nothing to do with crank end float. So the measurement you gave of 0.2mm is the pulley misalignment, not crank end float.

 

To make sure the pulleys are parallel it should be a straight edge across both. Its usual to shim the crank pulley, but yours would seem to be the other way. It could well be that everything is OK, not sure if your method of measuring is accurate enough.

[nicklouse]

i would never measure like that. as you are relying on to many unknowns straight edge across the sprockets and measure with feeler gauges and shim to correct.

[Sprocket]

Have you fitted a gasket between the fancy aluminium casing at the engine block? And if so was it the correct thickness?

[Steve220]

Ok Steve thanks for the clarification I have added my comments in italics

- On first view the crank sprocket appears to sit more proud than the camshaft. The photo was taken prior to tightening it all down although had been pushed back with a socket as a drift.

   Having thought about the photo I think it could just be the chain deceiving all of us, and now its been turned over a few times now it has settled to a more central place. The sprockets can't be seen well on the photo.

 

- The crank end float was within tolerance at the time of installing, it was actually on the tighter end of the tolerances.

How was it measured?, and how much float was there ?

 

- After running the crank over around 10 times i re-did a line of sight check then measured the distance between the chains outer face and the back plate. As above.

The distance at the crank sprocket to the back plate was 24.00mm and at the cam sprocket it was 23.80mm. Measured with digital verniers.

  Ok so you have measured the crank sprocket and cam sprocket, that will give you an idea of how well the chain sprockets are lined up, and has nothing to do with crank end float. So the measurement you gave of 0.2mm is the pulley misalignment, not crank end float.

 

To make sure the pulleys are parallel it should be a straight edge across both. Its usual to shim the crank pulley, but yours would seem to be the other way. It could well be that everything is OK, not sure if your method of measuring is accurate enough.

 

Crank end float was measured using a DTI and measured 0.055mm (0.0022").

[Spider]

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?

 

If the cam is ground correctly it can only ever thrust in to the thrust plate, it can't and won't don anything else ever. This is why when checking the alignment, the can needs to be moved (levered if you like) in to the Cam thrust plate. It won't bounce around, or thrust in any other way.

 

Never in 35+ years of building these engines have I fitted a cam that did not have tapered lobes, as be factory specs, and never have I ever bothered to adjust the Cam End Float if it's more than 0.004" and never had an issue.

 

If the cam is ground in some other way that differs from the factory fundamental design, then you really need to refer to the designer / grinder for their advice.

[Retroman]

 

Ok Steve thanks for the clarification I have added my comments in italics

- On first view the crank sprocket appears to sit more proud than the camshaft. The photo was taken prior to tightening it all down although had been pushed back with a socket as a drift.

   Having thought about the photo I think it could just be the chain deceiving all of us, and now its been turned over a few times now it has settled to a more central place. The sprockets can't be seen well on the photo.

 

- The crank end float was within tolerance at the time of installing, it was actually on the tighter end of the tolerances.

How was it measured?, and how much float was there ?

 

- After running the crank over around 10 times i re-did a line of sight check then measured the distance between the chains outer face and the back plate. As above.

The distance at the crank sprocket to the back plate was 24.00mm and at the cam sprocket it was 23.80mm. Measured with digital verniers.

  Ok so you have measured the crank sprocket and cam sprocket, that will give you an idea of how well the chain sprockets are lined up, and has nothing to do with crank end float. So the measurement you gave of 0.2mm is the pulley misalignment, not crank end float.

 

To make sure the pulleys are parallel it should be a straight edge across both. Its usual to shim the crank pulley, but yours would seem to be the other way. It could well be that everything is OK, not sure if your method of measuring is accurate enough.

 

Crank end float was measured using a DTI and measured 0.055mm (0.0022").

 

Looks like the crank and cam end float are fine.

We have all been deceived by the photo, as the chain can be out.

 

Its a simple sprocket misalignment and mis-measuring issue.

Measuring from chain or sprocket to backplate with a vernier is not accurate enough.

 

You need a straight edge on the cam sprocket and measure the gap under the other end at the crank sprocket...and shim the crank sprocket out so the two sprockets are parallel.

Job Done.

[Retroman]

 

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?

 

If the cam is ground correctly it can only ever thrust in to the thrust plate, it can't and won't don anything else ever. This is why when checking the alignment, the can needs to be moved (levered if you like) in to the Cam thrust plate. It won't bounce around, or thrust in any other way.

 

Never in 35+ years of building these engines have I fitted a cam that did not have tapered lobes, as be factory specs, and never have I ever bothered to adjust the Cam End Float if it's more than 0.004" and never had an issue.

 

If the cam is ground in some other way that differs from the factory fundamental design, then you really need to refer to the designer / grinder for their advice.

 

Ditto....never been an issue...never had to think about 'adjusting cam endfloat'

[Sprocket]

Just ignore me, thats ok.

[Steve220]

Just ignore me, thats ok.

Some of us work on the weekend and have minimal time for forum.

Yes and yes.

[Steve220]

Ok, so Ive pulled it all apart again and have a gap of 0.3mm/0.012 on the cam gear/sprocket

[Steve220]

Have you fitted a gasket between the fancy aluminium casing at the engine block? And if so was it the correct thickness?

 

Sprocket - I think this one belongs to you for an answer, chap!

 

So i bit the bullet and pulled the whole thing apart. Measured everything then gasket I put on Vs the spare on I have here. Turns out the gasket supplied with the DSN cover is thicker at 1.0mm and the standard rover item is 0.4mm. Typically I installed the Rover item thinking OEM is better. So i'm about to put it all back together and see what we have!

[Steve220]

Well there we go

 

Rover gasket

 

 

DSN gasket

 

 

Both pulleys drifted home and flat edge shows...

 

 

Bang on!

[Retroman]

The thickness of the gasket behind the front plate is irrelevant. There is no 'correct thickness'.

 

It has no effect on the sprocket alignment.

[Steve220]

The thickness of the gasket behind the front plate is irrelevant. There is no 'correct thickness'.

 

It has no effect on the sprocket alignment.

 

Not quite chap.

 

The thicker gasket pushes the triangular plate further out which in turn pushes the cam pulley further out which was what was needed in this instance.