Clutch hydr/mech.

Post by **janstolp** » Sun Oct 29, 2006 10:48 am

In my traveller I have a 1275 Midget engine with a hydraulicly operated diaphragm clutch.I had troubles with the hydraulics and want to go back to mechanical .I than found out it needs a lot of energy to move the lever.That i s ofcourse where the hydraulics were introduced.What I now want is a normal clutch for a 1100 motor with a mechanical operated lever.Problem is however that the holes in the flywheel do not correspond.The clutch for a 1100 is wider.The flywheel is attached to the crankshaft with six bolts.
I.e. is it possible to have a 1100 clutch fitted to a flywheel with six holes .
I hope the Question is clear
Regards Jan Stolp

Post by **bmcecosse** » Sun Oct 29, 2006 4:15 pm

Anything is possible of course - but possibly the best bet would be to use a 1098 flywheel (which obviously takes the bigger 1098 clutch) - and have it drilled to take the six bolts. Two of the existing 4 holes will line up as it is - some just do another two - but best to get all six in. Other option would be to drill and tap the crank to take all 4 bolts from the 1098 flywheel - this is just 2 holes to drill and tap and may be easier to line up using the flywheel as the guide.

Post by **janstolp** » Sun Oct 29, 2006 4:28 pm

Thank you very much for your answer.
I don't think a 1098 flywheel has two holes to take the two protruding "guide pins".Must I get rid of those pins or bore two extra holes for them as well or does that weaken it too much?

Post by **bmcecosse** » Sun Oct 29, 2006 4:42 pm

Dunno - haven't actually tried this - the guide pins 'may' fall in with the other two holes in the 1098 flywheel. They should be used if at all possible - the bolts are not really meant to transmit the drive - just clamp the flywheel to the crank. However - if it's not possible to use the pins - I wouldn't lie awake at night worrying about it! 4 or 6 bolts whacked up good and tight with a spot of Loctite on the threads should be fine.
Depending on which crank you have - Spridget or Marina - there may also be some issues with the centre section of the crank interferring with the 1098 crank - may need a wee bit of machining. Can you not just get a smaller bore master cylinder (or larger bore slave cylinder) for the hydraulic actuation of the existing clutch - this would give increased hydraulic pressure at the expense of increased pedal travel

Post by **janstolp** » Sun Oct 29, 2006 5:07 pm

The hydraulics have been on the car for years.I have the car a year now and I think I put the wrong oil in and the cup failed.And because I didn't like the whole cramped business in the crossmember etc I thought in my innocence I had better go back to mechanical.And that is were it all started to go complicated.I can also fit new cups and put it all back together but I don't really like that.Do you perhaps know that it is normal that a diapragm clutch needs so much energy to move.With my 80 kilo's it was just moving a little bit.

Post by **bmcecosse** » Sun Oct 29, 2006 5:27 pm

Normally a diaphragm clutch is lighter! That was the 'big improvement' at the time. Obviously it is smaller diameter - and so needs higher clamping force to transmit the drive. I find the mechanical connections on the 1098 work just fine - and light in operation.

Post by **janstolp** » Sun Oct 29, 2006 6:04 pm

This is the clutch I have in the traveller.In my saloon is a normal clutch with a 1098 cc motor and that one is light in operation.May be the clutch is at fault?
As I said before with my 80 kilo's I could just see a wee little movement and maybe that is not normal.

Post by **Kevin** » Mon Oct 30, 2006 1:48 pm

The midget flywheel and clutch is well know for being quite harsh with a sort of in or out action because its designed for a much lighter car which is probably why the hyraulic kit was designed, if you use a modified Minor flywheel the action is almost identical to the standard 1098cc, I think the difference are quite a bit size wise with the midget 6 1/4" against a Moggies 7 1/2" if I remember correctly.

Post by **janstolp** » Mon Oct 30, 2006 4:33 pm

Thank you Kevin and bmcecoosse for your reaction!
Regards Jan
I still hesitate a bit to drill the holes and I think I had better let a professional do the job with precise machinery. To keep everything exactly balanced.

Post by **bigginger** » Mon Oct 30, 2006 4:58 pm

VERY wise

Post by **rayofleamington** » Mon Oct 30, 2006 6:13 pm

Yes - as Kevin already pointed out, this combinationis well known for giving a stiff pedal and sharp clutch bite if used with a Minor mechanical linkage.
At least one person has improved the operation of their Midget clutch on a Minor by redrilling the hole in the pedal arm so that it uses a different lever ratio.
Simple is usually best.

Post by **bmcecosse** » Mon Oct 30, 2006 7:18 pm

That sounds like a good idea - provided the slave cylinder has enough stroke.

Post by **janstolp** » Mon Oct 30, 2006 8:52 pm

Ray is writing about the mechanical method.But to my surprise I see he is living in Leamington spa and that is exactly where the bloody clutch was made!!Borg&Beck co ,Leamington spa.