Variation in flywheel thickness

[janstolp]

Why is it that there are flywheels of different thicknesses.
I have one of 23 mm and also one of 29,6 mm (roughly measured)
They are both on a 1098 cc engine ,10 MA-U-H ........
Regards Jan

[janstolp]

I just measured the weight on the bathroom scale....( i.e. not exactly high tec.)
One was 7 kilo's and the other 9.6 kilo so roughly 37 % more.
Regards Jan

[bmcecosse]

How strange! Any signs that the lighter one has been 'lightened' ? Certainly use the lighter one unless you see any problems with it.

[janstolp]

I'll show some pictures but at the moment I am too greasy just having a cuppa..
regards Jan

[janstolp]

The first picture shows a thick flywheel on a 1098 engine with a 'normal "flywheel leaning against it.
The second is a normal flywheel on a 948 engine .Same thickness as the other "leaning "one.
The third is a thick flywheel.
Regards
Jan

[bmcecosse]

Interesting! So - 948 engines have a thinner/lighter flywheel? That's the 'new' thing I have learned today!

[janstolp]

Well the thickness of the 948 flywheel is the same as the other "thin i.e normal " 'flywheel.
I also have another thick flywheel and that was on a 1275 Midget engine I had on my traveller alas that engine is no more because of a failing aftermarket oilseal .

Regards
Jan

[philthehill]

The thick flywheel is off a Series 2.
The first picture is not totally 1098cc and the engine has been played around with as it has the thin 803/948cc engine back plate. Maybe a 1098cc engine block but the rear end is definitely not.
Again the second photo is not totally 948cc as it has the thick 1098cc rear engine plate.
The thin flywheel is probably off a 948cc engine but a photo of the pressure plate face would determine exactly what it is off.
Both 1098cc and 948cc engines are not standard as regards rear engine plates and the flywheel of the 1098cc if it in fact is a 1098cc engine.
Are the first and second photos labelled correctly? Me thinks that they should be labelled the other way round which would make more sense?

[janstolp]

The engine block of the first picture is a 1098 cc, the second picture is a silverseal 948 cc engine.
You say that the thick flywheel belongs to a series 2, so you mean the 803 ohv engine?
By the way thank you both for your comments!
Learning everyday
Regards Jan

[philthehill]

Yes - 803cc OHV engine.

For reference these are the part numbers of the respective flywheels:-

803cc.........................Pt No: 2A516E

948cc.........................Pt No: AEA594E

1098cc.......................Pt No: 12G1802.

As I said in my post above a picture of the clutch plate side of the flywheel would be appreciated and would confirm what flywheels they are.

[janstolp]

Here is the picture of the thick ,803 ,flywheel.
regards Jan

[bmcecosse]

My head's spinning (pun) now.. I thought the 803 and 948 engines had the thin/light flywheel?

[philthehill]

According to the engine sectional drawing of the 803cc in the BMC Minor Wksp Man section AA the flywheel is the thick one.
See drawing below.
The photo above appears to show a 803cc flywheel but I am happy to be corrected.
The clutch cover (Pt No: GCC132) is the same for the 803cc and the 948cc.[frame][/frame]

[bmcecosse]

The last thing the poor wee 803 engine needs is a heavy flywheel!

[LUR759H]

Well Jan the very fact that you are talking about flywheels indicates that you know a lot more about Morris Minors than me, so I dont think I'm the best person to make comment however I would say that I get the impression that these engines have been played around with and it might be that the flywheels have too been changed around, added to and bodged, as you say here in the UK.
I hope I haven't offended anyone but I think if you have three flywheels lying around then someones playing with engines....

Kind regards

Alan
I apologize for my English, Grammar and poor punctuation but since joining the site it has much improved.

[janstolp]

It's exactly what you say Alan in all these years there has much been played around but thanks to the knowledge on the forum we now know what is what in the world of the A-series flywheels!

Regards
Jan

[philthehill]

To be continued
And we have not even touched on the modified flywheels required for example to fit Marina to Minor or skimming the plate face and re-drilling to fit different clutch covers. The permutations are endless

[bmcecosse]

So -can the larger 1098 clutch be fitted to the thinner 948 fly? Obviously some redrilling/tapping required - but can it be done?

[philthehill]

As regards the fitment of the larger 1098cc clutch to a 948cc flywheel - it can be done so long as the clutch plate face is machined flat and the pressure plate securing bolts are index drilled and the location dowels again index drilled, both at the new locations.
Better if fitting a 1098cc gearbox at the same time for more clearance. If fitting to a 948cc smooth case gearbox the clearances must be checked before modifying/fitting the flywheel clutch assy.
It would be much easier to fit a 1098cc flywheel and clutch assy though. Again check clearances before undertaking any work.


I have a 1275cc Midget/Sprite flywheel which has had the clutch face machined flat, the securing bolts and the location dowels have been index drilled for the fitment of a 7.5" Ford RS 2000 competition diaphragm clutch.
All things can be done if you have the wherewithal and a bit of technical common sense.

[bmcecosse]

I was thinking to get the benefit of the lighter flywheel!