1275 midget conversion worth it or not?

[les]

I don't like the idea of drilling the Minor flywheel, too many holes! Could the Marina flywheel really be used, if reduced in diameter?

[philthehill]

Les
Having had a close look at the flywheel for sale in the link above I see no reason why the Marina/Ital flywheel could not be trimmed down in diameter and a step for the ring gear machined out at the same time - as suggested by bmc above.
The centre plate rubbing face of the flywheel would have to be faced off and new pressure plate locating dowels fitted, also the clutch cover retaining bolt/set screw holes drilled and tapped.
I would suggest that the above is more suitable when using a Marina/Ital crank than a re-faced/re-drilled 1098cc flywheel.
Also the Marina/Ital crank/flywheel register is retained
I recently had a 1275cc Midget flywheel refaced, locating dowels fitted & retaining bolt/set screw holes drilled and tapped (all done on a CNC machine in one foul swoop) to enable a 7.5" clutch to be fitted and it cost me £85 inc VAT. To reduce the overall diameter of the Marina/Ital flywheel and put a starter ring step in place should not cost much extra.
The re-worked flywheel should be re-balanced before use though.
I agree with you in that drilling a Minor flywheel to suit a Marina crank results in too many holes. 8 holes against the 7 of the marina and possibly the loss of the crank/flywheel register.
It will be interesting to see what faversham999 has to say.
Phil

[mike.perry]

If you are fitting the 1275 engine just fit the flywheel and diaphram clutch with modded 1098 linkage and to save thrust bearing wear you can also fit a roller bearing thrust. Job done!

[les]

I'll look out for a marina flywheel, and make a comparison.

[philthehill]

Mike
As said above the 1275cc Marina/Ital flywheel cannot be fitted to the 948cc/1098cc Minor crankshaft or the 1275cc Midget crankshaft nor can the 1275cc Midget flywheel be fitted to the 1275cc Marina/Ital crankshaft or 948cc/1098cc Minor crankshaft.
I am not sure where you are coming from as they are not interchangeable - do you mean 1275cc Midget engine/1275cc Midget flywheel which will work with the mechanical linkage - please elaborate.
The Marina/Ital flywheel question arose because of the post by faversham99 - see above.
The OP question I believe has been answered.
Phil

[midget]

Further to this--I have just been told by the Machine shop which I contracted to carry out the above mods to my A+ flywheel/crank, that they are refusing to complete as they believe that it will lose the requisite register between them.
I have decided to obtain ESM exchange Minor flywheel(to fit Ital crank) and modded back plate. As this flywheel comes with new ring gear fitted I think its the more economical solution.

[mike.perry]

1275 Midget engine, flywheel and clutch and modified 1098 clutch linkage. Sorry if that was not clear

[philthehill]

Mike
Thanks for the clarification.

Midget
The crank/flywheel register is most important what ever crank/flywheel is used.
I understand that the different registers were intentionally made so as there could be no mix up on the engine production line.

Phil

[midget]

Sounds feasible explanation Phil, but surely A+ were not made at Coventry along side older engine?
I was under the impression that it was a popular mod for Minors that had been done many times, although the machine shop has had no request for these in the past. Am I mistaken?

[bmcecosse]

ASK if the modified flywheel has the correct 'register' before buying... I suspect it may just have the extra holes drilled......

[philthehill]

The 1275cc 'A' & 'A' Plus engine - reading from 'The 'A' Series Engine Its First Sixty Years' refers to the new engines being made at Longbridge East Works.
As regards the flywheels - a most popular modification was for the 1275cc MG Midget crank (with 1275cc midget flywheel) to be fitted into the 1275cc Marina block which had the same main bearings but had larger big ends to compensate for a reduction in the grade of crankshaft material.
The 1275cc Midget flywheel could be faced off and a 7.5" heavy duty clutch fitted.
If you were really flush with the money a special steel flywheel would be utilised which was safer than a lightened cast item which could shatter at high revs.
Over the years I have tried most flywheel / clutch combinations but never come across (or used) the Marina/Ital flywheel being used on a 1275cc 'A' Series when mated with a 'A' Series gearbox.
This is an O/E 1275cc Midget cast iron flywheel modified to accept a 7.5" clutch.[frame][/frame]
This is the clutch cover to suit the modified flywheel.[frame][/frame]
Whilst the ESM Minor/Marina flywheel may no doubt suit some applications I would not use a flywheel without a register to locate the flywheel.
Having been let down by a well known and bought in modification which allowed the flywheel to loosen on the rear of the crank it was the register that saved the day and little if any damage was done.
I now run a special steel lightweight flywheel machined to have the correct 1275cc Midget register on the rear of a 1275cc Midget crankshaft.
And if you really want to go to town how about this flywheel especially made for me by Manx Racing in light alloy.

Phil[frame][/frame]

[faversham999]

My upgrade was done by ESM they tried my 1275 clutch and MG flywheel ,1st and 4th gear were difficult to get and the clutch was heavy . They made the changes the car now very good . It was also fitted with a 1098 refurbished carb