Clutch issues
Turbo Mini Forums

What is the reason why an engine with exessive axial movement will drop the revs when the clutch is depressed?
As long as the block isn't touching the crank, what causes the slowing down?

How many thou will be needed to give this effect?? I always aim for maximum 4thou when building engines, I know that some manuals claim more is OK, but I've never had any trouble.

Its the crank touching the block, or to be more accurate the bearing housing.

Not sure on how many thou give you the effect thou!!

Alex

AlexF

a heavy diapraghm will pull very hard on the thrusts which will slow it down i guess. simple way ive always seen it. probably not right mind!

plus i guess the rods go out of line with the bore

Now that I've adjusted the 1/4" bolt in, so that there's 1cm between it and the clutch lever, the clutch is fine.

I've taken the WOK off, and found nothing wrong. I haven't checked the crankshaft endfloat, but I just cannot understand how 3thou will affect this.

Your thrust bearing, if not of the floating type, will not be "perfectly* in line with the centre of the nose of the crank, and hence not ride perfectly on the end of the clutch diaphragm if you are on non-verto type. The heavier the diaphragm is, the more you will notice the mis-match.
It shags the bearings faster, and wears that little plate in the centre of the diaphragm that it presses on.
Verto clutches should all have the later "floating" bearing which will self-align when depressed.

On a non-verto lump, its going to be the thrust bearing....

That said, on an old B-series Iwas working on, when you hit the clutch, the shift in the amount of weight the engine was driving (the flywheel effect) was enough to lower the engine revs at idle with a pretty lean mix...

Well, I'd like to blame Canada, but I guess the thrusts are the reason:

Edited by Vegard on 29th Oct, 2004.

I'll be checking my thrusts when I pull my engine this winter.

Vegrad is there a grey clutch diaphram on your turbo?

Team Racing

That must've been more than 3 thou...

Is the crank goosed???

Yes...
10 thou!

i had a car at work a couple of months ago that had 2.4mm of crankshaft endfloat(that was measured without even stripping off any engine components)
when i took the sump off the thrust washers had fell out(somehow)

no longer a series, but still 1.3 turbo.