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Clutch choice.

Posted: Wed Feb 24, 2021 5:59 pm
by midget
Sure that it has been done many times on here, but I have a choice to fit either type of clutch available to a rebuilt A+ engine and 1275 midget gearbox, and would like an opinion as to which is preferable please?
I have both types of hardware (ESM conversion for Minor type, or 1275 midget flywheel) to fit.
I will be using mechanical linkage and have fitted a Midget crank.
So which is better?

Re: Clutch choice.

Posted: Wed Feb 24, 2021 7:09 pm
by philthehill
The ESM modified flywheel is not suitable for the 1275cc Midget crankshaft.
Personally I would go for the refaced and re-indexed 1275cc Midget flywheel with 7.5" diaphragm clutch.
The fall back position would be to fit the standard 1275cc Midget flywheel and diaphragm clutch with the revised length arm on the relay shaft.

Re: Clutch choice.

Posted: Thu Feb 25, 2021 8:59 am
by midget
Sorry Phil,I should have said that I could swap the crank and rods back to Ital type if that type was preferable.
However, it is the question of difference in operation of the two types that I was meaning. I am aware of mod to lengthen the clutch fork arm have a " Declan" linkage to incorporate as well.

Re: Clutch choice.

Posted: Thu Feb 25, 2021 9:28 am
by philthehill
The 1275cc Midget diaphragm clutch is more suited to the application than the spring clutch.
Both hydraulic and mechanical operation are suitable. I have over the years employed both types of operation and neither gave any problems. If you retain the mechanical linkage I would recommend that you upgrade the relay shaft chassis bush as it is not really man enough to cope with the extra loading. The best bush for this application was the Minor Mania hard plastic bush but a hard poly bush will suffice. You can still use the 1275cc Midget clutch release arm. Put a thread on the Midget slave cylinder operating rod and attach to a modified Minor clutch release rod with a threaded joiner.

Re: Clutch choice.

Posted: Thu Feb 25, 2021 4:30 pm
by ampwhu
if you are using a modified clutch shaft, which i would guess changes the fulcrum point and lightens the clutch, would it change the throw of the clutch fork?

i am fitting a 1275 engine (all midget) to a 1098 box using mechanical linkage. I have remade my own clutch shaft and have wondered if i need to do anything with the clutch fork. I am using a standard 1275 clutch (6.75") and a 1098 fork.

Re: Clutch choice.

Posted: Thu Feb 25, 2021 6:54 pm
by philthehill
Use the 1275cc release bearing with the 1098cc Minor fork arm.

http://gerardsgarage.com/Garage/Tech/TO ... arings.htm