7 replies to this topic

[Guess-Works.com]

Because of a recent engine failure, this has given me the opportunity to rethink the clutch and starter.

With the aim being to switch from an inertia starter to a pre-engaged, there are two ways of doing this, switch to a verto, or obtain a non-verto flywheel with a pre-engaged starter ring.

The only new ones available are of the lightened variety..... Shame :grin: !!

But anyway... Why not a verto I hear you say, and if you ever wondered.. what's the difference between the two....

Well apart from the exterior differences, i.e. the clutch slave cylinder is in different places, pre-verto it is located on the top of the flywheel housing with a long arm, whereas on the verto it located on the side of bell housing with a short arm, the internal differences are very noticeable, and quite simply work in completely different methods.

Both styles are basically made up of four components, the flywheel, diaphragm, pressure plate and clutch plate.

So, the verto clutch is pictured below, front and back.



On the front of the clutch is the diaphragm, but in the verto, is joined to the pressure plate as one unit. This is also the part which is connected to the crank shaft ( again different in the verto )



The other parts of the unit are the flywheel and clutch plate



The flywheel is connected to the sprung part of the diaphragm and the clutch plate is sandwiched between the two.

In a verto clutch it is the flywheel and diaphragm which is pushed away from the pressure plate ( the inner part of the diaphragm which is connected to the crank ) when the clutch is disengaged.

So what about the non verto.

The non verto, IMO, is much simpler and a lot easier to comprehend. Again it is made up of the four basic components. With the flywheel playing the main supporting role, and the part which is attached to the crank.



On the front is attached the diaphragm, and on the back, the pressure plate. These two are again connected, but by bolts through the flywheel.

With the diaphragm and pressure plates separated, you can see the round spring, which provides the ‘pinch’ on the clutch and the friction surface on the pressure plate.



likewise the friction surface on the flywheel and clutch plate.



How this works is, the flywheel is connected to the crank, and as you disengage the clutch the diaphragm is pressed which pushes the pressure plate away from the flywheel. Basically the opposite thing to the verto.

Question: Which is better ?

Answer: Depends what you are doing….

If you want a smooth town run-a-round to do the shopping, then the verto is the clutch, It is designed for the everyday car, and the springs in the clutch plate soften out the engagement, does not need adjusting and will last as long as your gearbox and engine, or there about.

But, if you want to play looney tunes with your engine, then you’re really going to want to be on a pre verto. The reason for this is two fold, the different diaphragm’s and clutch compounds available to you. When you hear mention of an Orange or Grey diaphragm, the pressure of the spring is being discussed, and Orange ( Fast Road) is stronger than standard, and Grey ( Race ) is stronger than Orange, and the stronger the spring the stronger the pinch which is applied to the clutch plate. Clutch plates also can be altered to higher friction compounds and also to what are called sintered plates, which provide very little bite before fully engaged, quite simply on or off.

Question: What about lightening?

Answer: This has nothing to do with thunderbolts!

I’ve heard it said that taking a pound of the flywheel is like removing 100 pounds from the car. Therefore the more weight you can remove from this section of the revolving parts of an engine the better.

A Verto clutch in it’s standard form weighs in at about 10.5 kg’s, 23lb’s. most of that weight is split fairly evenly between the flywheel (5.5kg) and pressure plate/diaphragm (4.1kg), Unfortunately this means there is very little which can be removed from either before the structural integrity of the unit comes into question. The most I’ve seen is a 1.5kg reduction.

On a non-verto, with an overall standard weight similar to that of the verto, there is much more to be gained. Basically the majority of the weight is in the flywheel, and over time with competition use etc. The weight of the flywheel has been reduced by nearly 50% in the ‘ultralight’ flywheels to 3.8kg. A similar weight loss can also be achieved in the pressure plate, saving another kilo.

With a total weight loss of almost 5kg ( 10lbs ), this outstrips the verto hands down.

An Ultralight flywheel. Just too dam pretty to hide away in the engine.



And talk about slimmers world, Standard top, Ultralight bottom.

[Jordie]

that cleared afew things up.

my new clutch is excellent, from mini spares and literally is on and off (pre verto).

Top man JG

[Madmax]

excellent, i think this deserves to go in the FAQ's

[Pickup76]

Ahh, always wondered why people say the pre verto is the best, now i know. Cheers GW

[TimS]

what would be needed then if satarting from scratch convertin gverto to non verto?i am really considering this now the engine is out

[Guess-Works.com]

Right, here's the deal...

First of all asses which sort of starter you are using, pre-engaged or inertia...

The easiest way to determine this is to look at the starter, and if it has the solenoid attached to the top of it, then this is pre-engaged, if the solenoid is separate ( normall stuck on the inner wing ) then the starter is inertia..

If you are considering changing from inertia to pre-engaged ( recommended ) then you'll need to obtain a new starter, and do a small amount of wire lengthening, can't tell you exactly what yet, cause I ain't done it..yet !

but on the clutch front you will need..

6(or 9) x Driving straps
3 x Strap to flywheel screw
3 x Locktab
1 x Clutch diaphragm assembly
1 x Pressure plate
1 x Clutch plate
1 x Slave cylinder
1 x Clutch release bearing
1 x 7/16ths nut and bolt for adjustment
1 x Pre-verto (long) clutch arm
1 x Spring anchor
1 x Clutch spring
1 x Anchor spring end
1 x Pre-verto plunger
1 x Clutch hose

Ohh... and a flywheel with you choice of starter ring..

The bits you can reuse from your verto setup are...

The flywheel locking washer and bolt,
The clutch/slave push rod
The clevis pins
The starter motor
The clutch master cylinder

It realy helps if you have an engine you can rob for bits

Piccie, red bits are new bits... that will be need on the outside ( apart from the slave and hose )

[Dan]

Depending on the combination of flywheel/starter/ringgear that you end up using there is sometimes a need to space the starter further away from the flywheel housing using a shim to prevent the gear chewing up the starter pinion. Washers under the screws won't do, you need to make a shim or the motor's torque will wreck the housing by twisting the starter mounting. Whoever sells the flywheel to you should be able to advise you about this, if not ask at Mini Spares Centre or check their website for Keith Calver's article on this.

Also depending on which pre-verto clutch release bearing and plunger combination you get you may need a retaining ring to hold the bearing on. You must use the right type of bearing for the plunger and use the ring if required by the setup you employ.

There is a thrust plate in the centre of the diaphragm assembly for pre-verto clutches which is held by a spring clip. If you buy a standard replacement diaphragm (uncoded, brown, blue) this plate is included and so is the clip but if you buy an uprated spring (orange, grey or double grey) the plate and clip are not always supplied with it. If you are using a second hand unit the plate and clip should both be renewed if the plate shows noticeable wear. These parts must be installed the right way around and the clip properly fitted.

I was under the impression that you need to use a Verto flywheel bolt with a Verto flywheel and vice versa since the bolt locking systems of the two don't interchange well (pre Verto uses a locktab whilst Verto uses an encapsulated bolt which should not be re-torqued according to Rover). But then I have only dealt with one or two Verto clutches so Guessworks is probably better informed about this than I am.

And remembr when changing a flywheel to have the crank the right way up or you'll never (really never, once you've started it it might well seize up completely if the crank is the wrong way around) get the old one off!

[Guess-Works.com]

Dan, good points, and yes I have also read that if you replace the ringgear on a flywheel from a inertia to pre-engaged you will need the spacer ( it's only a small size ), I believe that this is due to the machining of the flywheel. If you buy it new, eg the lightened ones, I'm led to believe that they are machined as to not require the spacer.

The bolt I was unsure about, and probably should have err'd on the side of caution, maybe best to keep like for like...

But what I would suggest is find a diaphragm ( fed up of calling them pre-verto )clutch mechanism and use the majority of that, Jordie may be a man to talk to...