17 replies to this topic

[johnnysti]

Hi all

Just looking around as im bored at the mo and while looking for things to get for Bertie found this
http://www.minispare....aspx?pid=35440
Why isnt it recomended for road use? Which one is best to get? The car is only a weekend car (if its lucky) and im not sure if my car has a verto or not (dont even know what that is!!!)

Johnny

[The Matt]

The reason they aint recommended for road use is because of the engine being free-er to rev and also decellerate. When you floor it there is less rotating mass so it will enable the engine to accelerate better, when you take your foot off the throttle there is still less rotating mass, so it won't run-on as long (which aint ideal in stop starty driving conditions I guess).

OMG that is badly worded, but I know what I mean!

[The Matt]

Generally the easy way to ID the type of clutch/flywheel assembly is to look at the clutch arm on the end of the bellhousing (the arms that the slave cylinder pushes), a long one is a pre-verto, a short one is a verto.

[Papa Lazaroo]

I'm not entirely sure but I think pre-verto clutches are pretty rare and are mostly confined to much early minis? Aren't most 1980s+ minis verto?

[johnnysti]

Mine is a 1970 mini but in its life i dont know whats been kept or changed!!??

Heres a pic
http://img.photobuck.../vertoornot.jpg

Does this help???

Also, is it worth changing? Will you notice the difference and is it hard to fit?

Thanks again

Johnny

[minimadjonesy]

johnny,

that's a verto clutch!

[The Matt]

They are quite difficult to fit yes. It won't be a 1 hour job put it like that.

[The Matt]

Oh, and yours is a verto!

[johnnysti]

johnny,

that's a verto clutch!

Hey Alan

Does that mean the wheel if ound at the start of the thread is no good then? Can i get a wicked one for a verto?

Johnny

[Guess-Works.com]

It's not no good, it just means you'll need to convert from a verto clutch slave and mechanism to a pre-verto ( Diaphram ) clutch mechanism...

Vertos can be lightened, but not to the same extent as diaphram, if you do want to go that way, I can probably get one done for about 50, which would be a lightened flywheel, pressure plate and the faces skimmed ready for a new clutch plate...

PM me or MRA-Minis if interested.

If you do decide to change to diaphram, then you will also want a lightened back plate http://www.minispare....aspx?pid=32797 and a decent clutch plate and diaphram.. don't expect much change from 250

[johnnysti]

Thanks everyone, cheers GW.

With all that said then, is it going to be worth doing?? My missus hates me having days off work because i get bored and spend too much!! (you will see it all unfold tonight Alan aka mad jonesy)!!!!!!!!
Whats worth getting done instead then?

Johnny

[dklawson]

In general, greatly lightened flywheels aren't recommended on the street cars because engines so equipped can have difficulty achieving a smooth, low-speed idle. The flywheel's job is to provide some inertia at low speed ( in addition to working with the clutch and supporting the ring gear ).

[Sprocket]

This extremely light flywheel is so, to enable the engine to rev higher, such as in race engines with race cams. The down side is the idle suffers dramaticaly as there is not enough inertia stored in the flywheel to smoth out the pulses from the firing of the cylinders. This also gets worse with long duration cams. Correct me if im wrong( which i am a lot) but all out race engines idle around 1000rpm or above because of this. This would not pass the MOT.

if you are going to buy a new one buy a lightwieght steel one and a steel backplate, not the ultra light one. Lightened standard flys can in some instances explode if not done right or lightened to far. Safer bet is the steel one

[Leonard]

if you change from verto to pre-verto, can you still use the same starter motor?

[dklawson]

I think a specific idle speed for a race engine is hard to define. I believe the speed they idle at is arbitrarily set by the tuner to keep it running reasonably without fouling plugs.

The real advantage in a lightened flywheel isn't a higher top end, it's greater acceleration. By taking mass off the flywheel you allow the engine to rev up faster which translates to better acceleration times for the car as a whole. There are formulas to apply but I've routinely heard round numbers bantered about implying that 1 pound off the flywheel is like taking 100 pounds off the car.


OK side bar:
This is a question for you people who know the old cars and in particular the older BMC variants like the MG-1100. CAN I use a flywheel from a 1098 transverse engine on my 1275? Are the crank tapers the same? There's a NOS flywheel on eBay at a good price but I can't match the BMC/MOWOG number the seller gives for the assembly. He says that it's a flywheel for an MG-1100. Please let me know if I can use a 1098 flywheel on my 1275. Thanks.

EDIT: About that verto/pre-verto question above... I've been told that the two are not interchangeable but I don't understand why. I know that the pre-engaged starter doesn't require that the ring gear teeth be chamfered. So this would prohibit you from using a Bendix starter on a verto flywheel. However, I don't know why you couldn't go the other way. I would think you could use the pre-verto flywheel with a pre-engaged starter... but I thought someone had told me not to. I have an Australian acquaintance who runs a pre-engaged starter from a Holden on his pre-verto Mini... so there's at least some anecdotal evidence that you can do it in some circumstances.

Edited by dklawson, 06 January 2006 - 09:21 PM.