Flywheel advice needed

Ok attached is a picture of my flywheel and as can be seenit has a ridge on it (less than a 1/64 ")
question is do you think this can be machined out and still have enough meat or should I bite the bullet and get myself a aluminium one ?

would really love your thoughts

Should machine out just fine.

1 Like

That’s what I’m hoping i heard somewhere but may not be true that it has to be ground and not milled?

Rotary milling, then a surface grind is what most reputable shops do.

If Gary has the crank out of the block would you advise bolting the flywheel to the crank
to check run out , if any ?

The machine shop should be able to do that, wrt the mating surface, for the crank.

just curious, what engine size and was it a spring or diaphragm clutch? Pat

OK I’ll try to respond all in one answer.
Damn you gotta love this site.
Wiggles:- that’s what I’m hoping
Peterjb:_ That’s a good idea but at the moment it is on an engine stand
Matchlesspat:_ not sure how this is relevant or is it perhaps a fetish of yours :slight_smile:
or maybe you have some information that I can use (please)

As always thanks for all the input VERY much appreciated.


dumb ass I forgot to answer

its a spring clutch

You don’t say what this is going into, but in general, absent any other drive train modifications, an aluminum flywheel will make moving from a dead stop more difficult. If this is a heavier saloon, an aluminum flywheel is not for you. Rule of thumb: Light car, light flywheel, heavy car heavy flywheel. Same for the rear axle ratio. Under 3.54, heavy flywheel, 3.73 and up, light flywheel.

1 Like

Good thoughts, although I have fitted a light one to my my E Type and that seems fine, but this is going on my MKII 3.8.

Kerb weight of the E is 2900 lbs and the MKII is 3300 lbs not a huge difference but maybe enough to make what you say worth thinking about.

FYI, When my shop disassembled my 3.8 engine from my S Type, manufactured in November '64, they found the flywheel was drilled for both the spring clutch (10 inch) and diaphragm clutch (9.5 inch). That makes it simpler for me as I plan to upgrade to the diaphragm type for ease of operation.

Now that’s a really good thought and my flywheel has a lot of extra holes drilled, so maybe mine also may take the diaphragm clutch ?.

To me - ultimate goal would be a 10" diaphragm. But this does not come from Jag linepup AFAIK.
This would make things easier with T-5 setup (Jeep 10" clutch plate).

Mine had the additional holes but they weren’t the correct diameter and thread. I decided to use the original spring type.

Well check out the Laycock 10” diaphragm fitted to early 4.2 E Types,
you might find one NOS.
Peter B

I used a spring type 10" pressure plate with a standard mustang 10" disc (for my T5). Works great, it’s not too heavy on the leg (as everyone said it would be) and grabs really hard and firmly.

Gary, pull those pressure plate locating pins out first if you can and save them. I drilled a smaller pilot hole straight through so I can punch them out next time. Or the shop may do it. Then the shop can just cut straight over the whole face, much easier for them.

1 Like

Great thought I am going to remove them and I love your idea of drilling a hole which means I shall have to use my new drill press that I set up after owning it for 5 years :).

Um… be VERY careful, using a inexpensive drill press to drill a precise-location hole: normal twist bits and cheap drill presses do not easily do precision drilling.