I've set up a molasses bath and have cleaned up a few rusty mini bits , i pulled a rusty flywheel out today ,( been in for 2 months ), hosed it off , dried it , i'm impressed . I also pulled a crank out that had been in for the same time , cleaned up nice .

Here's a pic of 2 flywheels , a rusty one that i have put in the bath today, and the one on the left that i took out today .



Can someone explain the differences between the 2 for me please , one being a 2 piece .

Fantastic result.
I've been using vinegar baths but will give molasses a go. What ratio of water to molasses did you use?

Cheers
Eiles

Approx 50/50 , mixed the molasses (came in a 14 lit tub ) in a bucket with hot water to dissolve it well , and then topped up with water .

I understand the difference to be the earlier 2 piece had the centre turned from steel, the later 1 piece was machined from the casting and was there for not as strong. I have heard it said (from an old time Mini mechanic) the 2 piece is less prone to fretting the crank, I don't know the truth of this and have always just made sure both surfaces where clean and in good condition and lapped them together lightly as Vizzard suggested in his first book
As for rust removal I have been using washing soda and a battery charger, it is a lot quicker but yours looks like a much cleaner result, where did you get your molasis?

You can buy molasses from any horsey supplies shop, or stock feed merchant.

Re the flywheels, I've seen less fretting probs with the 1 piece cast iron one, however I always lap them on anyway.
You can lighten both types, if you don't go overboard. However I've only done this by turning, I don't drill dirty big `oles in em.
Don't try to lighten the thick centre boss of the 1 piece one, cast iron needs that thickness for strength.

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DrMini- 1970 wasaMatic 1360, Mk1S crank, 86.6HP (ATW) =~125 @ crank, 45 Dellorto (38 chokes), RE282 sprint cam, 1.5 rockers, 11.0:1 C/R.

Goodie results there!!!!! .. no seriously, it does make sense to concoct one of those brews if you have the space..... i am jealous..

now thread hijack .... for flywheels that are on and off a lot ( race engine etc) , what are the symptoms/ results if the flywheel creeps up the crank..AND if so would it be advised to use a metal spray filler once every now and then to build up the taper??? ... i am ALL for lapping and getting the right fit, but a 50 year old crank with 20 years of race life has me wondering? Darryl

I would not trust metal spray for this, usually the flywheel hub (on the 2 piece) wears more than the crank does. Find a better hub and swap it like mickmini did recently.

If it goes on a long way past normal, it will foul the primary gear's C washer, however you can machine the recess in the back of the flywheel hub deeper to clear.

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DrMini- 1970 wasaMatic 1360, Mk1S crank, 86.6HP (ATW) =~125 @ crank, 45 Dellorto (38 chokes), RE282 sprint cam, 1.5 rockers, 11.0:1 C/R.

So the single piece 1 is a later type, will they only fit smallbores, or are all flywheels the same ? Will they fit a 1275 ?

I have another 3 rusty ones that i'll clean up soon , along with other engine bits (clubbie ) that i'll sort through soon .

I gave up on that idea and got a MED all steel flywheel instead. GR told me that changing the centre piece was more trouble for balancing than it was worth given the cheap price of the all steel flywheels. The steel ones are lighter than you could ever make a cast one anyway.

And if you count 5 years ago, yes it was "recently"

cheers
michael

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the world is a book, and those who do not travel read only a page
66 Mini Minor sponsored by http://www.lifeonthehedge.com.au/ The Dog Harness Specialists
It was a pleasure ausmini. I'll miss all you misfits and reprobates

All diaphragm spring flywheels (both types) will fit bigbore and smallbore, except to an 850 with the early wet tail crank (which was only 1-3/8" dia not the usual 1-1/2".

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DrMini- 1970 wasaMatic 1360, Mk1S crank, 86.6HP (ATW) =~125 @ crank, 45 Dellorto (38 chokes), RE282 sprint cam, 1.5 rockers, 11.0:1 C/R.

Thanks Doc .