New Cranks / Rear Flange

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D Johnson
Posts: 21
Joined: Wed Feb 04, 2009 10:39 pm

New Cranks / Rear Flange

Post by D Johnson »

Hi All

I have the problem of an OHV engine that has a cracked parallel rear flange.

Firstly does any one have a spare parallel flange or have the dimensions so I can have one made. (I know this has been asked before)

The second option would be to replace the crank. Does anyone have experience with new cranks who can i get them from, how much do they cost and how long would it take to get one.

Also when the engine was removed the front engine mounting was found to be broken does anyone know where i might acquire one of these.

Is there a second hand part dealers for Morris parts.

Thanks

For all your help
Ian Grace
Site Admin
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Location: USA

Re: New Cranks / Rear Flange

Post by Ian Grace »

See my e-mail!

Ian
Ian Grace
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Posts: 5035
Joined: Sun Nov 19, 2006 12:55 am
Location: USA

Re: New Cranks / Rear Flange

Post by Ian Grace »

From Paul Rogers:

Colin Lee had exactly this problem. The parallel crank really is only fit for show pieces and you shouldn't bother with it if you intend to ever drive your car. All of the flywheel load is taken by the key which, however well you make it, won't last long. The flywheel will then be able to rotate through just a degree or two until eventually the flange splits along the keyway. Making a sleeve which is a good press fit onto the end of the crank is also futile since this introduces a hoop stress leading to premature failure of.... the flange keyway.

So, get hold of a taper crank and associated flange. There are sure to be spares sitting on shelves, though the MG people will probably have killed a lot of them off already. Failing that, either call Mike Dowley at Sports&Vintage, or try Phoenix crankshafts. I think they now make/have Minor/Mtype cranks which I think are VERY slightly shorter than the Jtype ones. This will probably need new rods to suit, so definitely the most expensive options.

Whatever you do, be sure to lap the flange onto the crank. Get a new nut and torque it to 100+ lb ft (how brave do you feel? Mine is 100 from memory) Loctite it in place.

Paul
halbe
Posts: 447
Joined: Sat Nov 10, 2007 11:08 pm
Location: holland

Re: New Cranks / Rear Flange

Post by halbe »

Hello,

What would be the the engine number where they changed the crank/flange to the tapered spec.?

Regards,
Halbe
Ian Grace
Site Admin
Posts: 5035
Joined: Sun Nov 19, 2006 12:55 am
Location: USA

Re: New Cranks / Rear Flange

Post by Ian Grace »

U12326, so you are safe!
halbe
Posts: 447
Joined: Sat Nov 10, 2007 11:08 pm
Location: holland

Re: New Cranks / Rear Flange

Post by halbe »

Thanks for the peace of mind
Now the only thing to worry about is the frost crack in my block :(

Regards,
Halbe
Toby
Posts: 1017
Joined: Tue Jan 09, 2007 4:49 pm
Location: New Forest

Re: New Cranks / Rear Flange

Post by Toby »

may have 2ndhand crank if needed... :D
if it's got wheels or chips - it'll cost you dear
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