Ruairidh

Far be it from me to question a veritable Austin Seven guru but I thought the only difference between the B&B and N-B set up was the setting of the clutch levers. I have certainly swapped both types of clutch plates into the same flywheel and withdrawal plate (cover)without problem. What makes you think the flywheel and withdrawal plate are different?

Location: Beautiful North Hampshire

Hi Martin,

I did study Guru Nanak at University many years ago... :)

I think that one flywheel design has a raised surface for the clutch plate, the other type is flat, this has just been confirmed via email (thank you very much).

I had wondered also if the centre boss was raised on one type and flat the other...

Can anyone offer which flywheel belongs to which type of clutch please? We think we know but would welcome hearing the same as our conclusions to be sure...

Thanks again.

Judging by the number of you who have kindly taken the time to help me via email and phone, thinking that there is no difference between the two, I think mine is a pretty obscure request and some explanatory photos are in order.

Here is my understanding:

Borg & Beck and Newton-Bennett clutches both have lined centre plates, they look very similar but the holes are spaced differently and one lining cannot be use on the other type. The design for each is slightly different also.

Here are both types of centre plate beside each other, it should be noted that they are smaller than the Austin centre plate. The lower plate should be lined and you can see the holes ready to accept this.




I am of the opinion that the flywheel for each type of clutch is also subtly different, I hope the following photos will explain my understanding of how each can be identified.

Borg and Beck

Centre plate is a single piece of steel, as below:



Flywheel has a raised area in the well that the clutch plate will run on as shown below:



Newton Bennett

The centre plate is made up of three layers of steel as shown below (the lining is removed from the example below):





The flywheel is is completely flat in the well which makes the surface for the plate to run about 1/16" deeper than the B&B.




A photo of both flywheels together for comparison:




I would be interested to know if anyone has a different understanding to me.

The problem experienced when mixing the two types (in my instance a N-B centre plate and B&B flywheel) is that it crunches into gear, I am hoping fitting the correct centre plate will rectify this but will report back for those interested.

Many thanks to all who contacted me, particularly Ian W who supplied some of the picture - thank you!

Father had clutch troubles on the RP in the 1990's with the rebuilt engine. Probably because he fitted a parts bin Ruby one believing it to be 'better'.

The problem he had was drag like you say. With the levers set correctly it woukdnt disengage enough.

Dads soloution was to fit washers cut in half between the flywheel and the cover plate. Obviously fitted in situ with the box on. These are about 1/16.

Sounds like it has a mixture of late clutch parts.

For completeness one item R forgot to note is that all of the above explains the 1938 Austin Service Journal advice about the need to adjust the height of the toggle levers when changing from a B&B plate to N-B plate. I also found reference to Austin manufacturing several types of 4 spd toggle lever presumably to suit the differing clutches, can any one shed any further light on this? After all these years and with so much written it is amazing what one can still learn about these fascinating little cars.

Location: Auckland NZ

Is the newton bennett plate 1/16 thicker than the Bork & Beck?

It most likely is Hedd - three plates vs the B&B single plate.

Ian - thanks for all your time and help today - every good day is "school day" :)

I've just fished out an example of both. Like Ruairidh's, my NB is unlined and the BB lined but the three layer NB measures 3/32" thick when all three layers are fully compressed wheras the BB seems to be 1/32" thick (not the easiest thing to measure with the linings on).

Steve

Location: North Yorkshire