I've been told it may be possible to fit a Cooper 997 crank to an 1100, anybody have any ideas/opinions?

Why would you want to? Wouldn't that effectively shorten the stoke turning your 1100 into a 997?

That was the issue I had with it - someone suggested it but I can't see how it would be beneficial

Back in the 60s I had a 997 motor that broke its crank. We put an 1100 one in, no problems.
Had to deck the pistons a bit.... but OK, it went real good.

New 997 Cooper cranks now are as plentiful as a Dodo.... but you could find a NEW 1098 one if you look hard enough.

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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.

Doc, when you say that itt had to be decked, it more or less means that they're interchangeable, right?
Is there any kind of power gain, or is it more or less negligible?
The idea was posed by a friend of my dad's, who has a 997 crank, and who thinks it is possible, and might result in a longer stroke than an 1100 crank.
This is all passed on to me though my other half, so I apologise if it doesn't make any sense, I might have misunderstood. I'll blame the heat.

997 stroke is 3.20" (81.33mm)
1100 stroke is 3.296" (83.72mm)

It'll be shorter stroke..

A 997 willll rev better and higher more smoothly..though 1098's have no problem with revs imo..

But It will have less torque and ultimately less power..

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Starlet Conversion:
http://www.ausmini.com/forums/viewtopic.php?t=15484

997 cranks were weak, it will have no more `revability' or be smoother than a 1098. They were a weak crank....

Erin, you will lose power as displacement will be now 1066cc not 1098.
reason I had to deck the pistons is, they were 0.048" further up the bore, and stuck out the top a bit.

_________________
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.

doc where would one acquire such an item as a new 1100 crank

Minisport UK had them on special a month or so ago, around 100GBP I think. A mate bought a new 1275 crank there for 150GBP.

Then they will send via UPS etc, and you will be up for duty, GST, `handling charges' etc.
So yes can get still, but not real cheap.

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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.