revs dropping with clutch in
Turbo Mini Forums

why would you need a regrind when I didnt need it?

i had mine do this when i converted to pre verto with ultra lite fly wheel, grey plate and paddle clutch, it kept dropping the rpm, but i adjusted the clutch stop so it was just pressing the flywheel housing and it didnt do it any more, now its fine, may be its not this prob but i figured thats what they were there for to stop you loading the thrusts??? or is it just the pressure of the grey plate that causes these thrusts to wear out??

I'm having the same problem now.

Pressing the clutch petal, drops the revs by about 500rpm.

It didn't do it until I changed the clutch arm and re-adjusted it as per Haynes.

Should I be checking thrusts, or is there anything else that causes this?

In the 13's at last!.. Just

Hi,
Try tightening the big nuts up a little.. It maybe over throwing with the new arm on.
Cheers,
Gavin :)

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No idea ot be honest mate, if it wasnt doing it before your clutch arm broke then its probably down to adjustment?

http://www.manchesterminis.co.uk/index.php...sosinfo&sosid=9

That page comments about the haynes method not being entirely accurate and theres another method there.

Try it first before you have to pull anything I guess. :)


Reading the other posts I remember when I built my block up STD size thrusts wouldnt fit between my crank and block.

So I took it to the local engine machinists and they machined the crank and the thrusts went in ok, little to no endfloat though which i was concerned about, but they said they will wear in ok once used? :S Im paranoid.

Edited by richminiturbo. on 31st Aug, 2008.

Cheers guys. I'll have a look at the adjustment as per Daves description before I start pulling it apart.

In the 13's at last!.. Just

i have tried everything, but no amount of adjustment makes any difference to the rev-dropping. It makes no difference to the operation of the clutch either.

The revs drop by about 500rpm as soon as I touch the pedal, so I don't think it's due to throwing out too far.

I have got a fair bit of play in the arm though. Is this normal?

In the 13's at last!.. Just

Hi,
Could it be the release bearing is knackered and the drag is what's slowing the engine? That's the only thing I can think of that would happens as soon as you touch the pedal.
Cheers,
Gavin :)

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Right lads, I am starting this back up again as I am having the same symptoms on my mk1.

Now the thrusts are new, and I cannot remember what the end float was. Today I had a play with it, gave it a bleed and it started to work, but the revs still drop not as much and it didn’t stall. Then I had a go with the spring removed from the arm and I could drive it up and down the street.

So the big question is what should I do now then? I am not too keen on pulling the engine.
Thanks Simon.

I have started posting on Instagram also my name on there is turbomk1golf

Nothing is impossible it just costs more and takes longer.

I have always found new thrusts tend to cause a drop in revs for a short while, then the symptoms subside. I found it worrying at first, but the last 4 engines I built all did the same and none were a problem.

It was worrying as it would stall last week when i did it.

I have started posting on Instagram also my name on there is turbomk1golf

Nothing is impossible it just costs more and takes longer.

just had a skim read through all this and im not sure if its been mentioned but...

I have had rpm dropping problems before now, and this was due to not having any oil pressure after starting the car when it was warm.

If you start the car cold it will take about 5 seconds to get pressure? and if you press the clutch in when it hasnt got any pressure the revvs should drop (dependant on diaphragm, i have a grey one). And this will cause the thrusts to wear out quite quickly. so in the next few days of driving the car it got worse and worse. Anyway i replaced them and i now never press the clutch untill i have pressure. if you do (which i have done by accident) i can feel the engine diing. But this is only if you dont have pressure. Im guessing this would be the cause to most problems you guys might be having? cause i know a lot of people just start their cars and drive away without waiting for oil pressure?

Mine takes about 8 seconds when its hot to build up pressure.

I always start mine in neutral with the clutch off...starter will barely crank the engine if it is engaged (orange diaphram & light fly). I had the rev drop issue with my new motor, but after a few hundred miles, no problems now with rev drops, but still won't start with the cluch in.

Eric
my pics.... http://www.fototime.com/inv/7AAF37CF3EFA956

simon , it does sound a bit like you have a bucket load of pre load on the clutch ,what about doing up the big nut on the end of the wok ,until it start to be hard to shift gears,then give it a bit more play .or what about setting the clearance to tthe manual ?

Edited by robert on 4th Jun, 2011.

Medusa + injection = too much torque for the dyno ..https://youtu.be/qg5o0_tJxYM

Fastest 998 mini in the world? 13.05 1/4 mile 106mph

Bit of a post excavation here.

Ok, i managed to get a temp clutch master cylinder on the car today. All went well until i put my foot on the clutch, and yes, you've guessed it, the revs dropped a good 300-400 rpm.

Now as background, the engine is freshly built, brand new rover crank etc, pre-verto ultralight flywheel and what i recall is either a grey or double grey diaphram. Up until today, the car has only been run a few times and not driven, today was the first time the clutch as worked to engage drive. Also note oil pressure is steady when the clutch is depressed. If i recall, the thrusts were at the tight end of the tollerance when they were installed.

Now reading above, a few have suggested this can happen with a new built engine. My question is, how long does it take to bed in before it settles down? I don't want to screw it up now if i can avoid it.

Your thoughts are appreciated as i'm just about ready to pull the whole lot back out the car

has the car /clutch been stood any length of time Rab

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Engine has been built for a couple of years.

i would press the clutch in and out a few dozen times without the engine runnnig as the diaphram spring can stick/ rust where it sits on the flywheel , this will not allow the diaphram to pivot correctly and just push the lot towards the thrusts,

try a litte lube between the two parts if you can get it in there, spray a little duck oil etc


carl

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also rob , make sure you have enough timing and mixture right so there is as much bottom end trq as possible .

Medusa + injection = too much torque for the dyno ..https://youtu.be/qg5o0_tJxYM

cheers guys.

I'll double check timing as it is on an old megajolt map. As for fuel mix, i'll need to connect the afr guage.

Will let you know how i get on