revs dropping with clutch in
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got my car out of the garage yesterday and when i press the clutch the revs are dropping by about 400rpm.
Its been about 1000 miles tops since it had new shells/thrusts etc, surely the thrusts aren't fooked already are they?

recently swapped to an ultralight flywheel and a grey with a Rally plate, since i fitted it the clutch as slipped like crazy, so i took off a driving strap from each post as it had 9 in total, clutch was a bit better but still slipping with just 6 straps in total. Just thought i'd add this incase it could be anything to do with clutch setup rather than the thrusts.

i had planned on taking the flywheel setup off next weekend to measure it all up to get full clamping.

Nick.

If the thrusts are fooked, it's easy to measure the crankshaft endfloat. Remove the starter motor, and put a dial gauge on it. Use a crowbar to wiggle the crank back and fourth on the damper pulley.

Where to mount the dial gauge, that's another story :)

cheers dude, hadn't thought of that. i'm sure i can make some sort of bracketery for the dial gauge :)

just a thought, you might be able to get a reading by sticking the probe in the timing hole on the clutch end plate and stick the magnetic base on the block just above.

my engine was doing this a few weeks back, it was my thrusts which where fooked.

Team Racing

arse.........looks like i'll be off into the garage now then to find the damage.

Anyone got any ideas what could cause them to be knackered after 1000 miles though? I dont sit on the clutch at traffic lights etc, its only had 9 emergency starts at avon. just really miffed by it all. :(

think i've found the cause of the problem.

my pedal box is fooked and the clutch pedal isn't returning fully, you have to hook your foot under it and pull it back up and it takes a fair bit of force. So it looks like its constantly been putting load on the clutch which would explain the slipping aswell probably.

tested it before i pulled the engine last night, with the pedal fully up it idles at 1500, press it down and it drops to 1000, let the pedal push itself back up and it idles at 1200. not until you hook your foot under does it come back to 1500....grumble i hate those feckin clevis pins.

bugger

Can i re-fit the new thrusts without taking the whole crank out? all i've done for now is taken off the centre main and slid the top half of the thrust round to pull em out, so hopefully re-fitting is the reverse of removal?


*edit* i picked that chunk off with me finger nail

Edited by Nick on 6th Sep, 2005.

Provided your crank is not badly damaged and clean of bearing swarf you should be fine, just recheck the end float.

Give it a good blow out with the air line and lube it up well.

JF.

cheers dude :)

Just to add. When this happened to me, I had to regrind the thrust faces of the crank. If there's ANY scoring there, you'll have to do this. If you can feel any ripples with your fingernail, a regrind is mandatory. If not, the new thrust bearings would sit on the "high" spots, and when these are worn into the bearings, end float would be massive.

Edited by Vegard on 7th Sep, 2005.

cheers dude, i had a quick feel of the crank last night and it felt ok...will check it over properly tonight though :)

i'm guessing when you have the faces ground that you use oversize thrusts?

and excuse the dumbness but how do you take up excess end float in the crank and cam if there is any?

ah cool so its just with the thrusts then to take up the float...just thought there may have been some other magical type of shim or something.

and yeah been there done that with the fecking woodruff key, i usually end up bodging my primary gear puller on to take off the chain wheel and knocking the key back into place with a screwdriver.

looks like the crank does need a regrind aswell, bugger!

Hello,

I made my engine new. (crank, bearings, thrusts,...)

After installing the clutch (lighten, grey diaphragm), at the first run the rev drops a lot. I don't know how many revolutions, because i do not wantet do destroy anything and went of the pedal. So i checked the clutch for correct install, spacers and so on but i could not find any mistake.

So i installed a standard clutch (not-lightened), with a blue diaphragm. And now the rev drops a little bit. About 100-200.

IS THIS NORMAL? Has the engine to shake down first? Or is there any other mistake in the system?

pre-verto
long lever
new thrusts

Regards,
Andreas

http://www.minifreunde.at

Andreas,

My engine is newly built and has a double-grey. When I first tried the clutch it was horrendous as the revs would drop 200 to 300rpm.

Now I have used it a bit (car not roadworthy yet, but moving in and out of garage etc) the revs now drop maybe 50 to 100rpm, I suspect as the thrust washers are bedding in to the crank surface.

It is not nice at all, but see how you get on with it......

With a blue diaphragm it should not drop at all.

We had exactly the same with the new engine this time, Tom. It was a worry at first, but now it is back to normal.

http://www.twin-turbo.co.uk
http://www.hillclimbandsprint.co.uk/default.asp

A man without a project is like a like a woman without a shopping list.

Cheers Ben, that is nice to know.

Thanks, good news!

http://www.minifreunde.at

Alright, new similar problem, I have an just built engine here, checked crank endfloat myself, and its good. But still it stalls when clutch is depressed, what else can this be?????

So André what was the reason for the rpms dropping?

you like to pull my leg dont you VeRg? I will admit I was a big jerk and had one of the thrusts the wrong way around, luckily I understood it early. Will post a piccy of the thrusts later on.

Nice eh?

cranks okay though, as I used the clutch only 10 times before I understood that something had to be fundamentaly wrong yes I am a FOOL:)

Edited by miniminor63 on 16th May, 2006.

Hi,
A very lucky one though! If that happened to me , I'd be needing a crank re-grind :(
Cheers,
Gavin :)

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