has anyone heard of mini cranks splitting, in particular the 1100 cranks?

i want to know the strengths of these things, or would it pay me to shot peen it etc if i planned on turbocharging my engine:) I dont want to spend money on the block to have the crank split and punch a hole in the side of it

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[Maverick] 1971 Mini K

I put 8 cracks in a NEW 1100 crank in 20,000 miles..... but I did rev it past 9000 lots of times.... not a good idea.

And, I snapped the back off an old 1100 one, and the front off an 850 one ...

I'd find a standard one, or a NEW one if possible, grind the pins if needed, balance it, then get it shot peened, or tuftrided. and DON'T rev it too hard!

Really, a 1275 with large journal crank is better- it has bigger bearings.

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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.

thats what im worried about, although i dont want mine revving that high anyway. I want to keep boost to low revs if i possibly can to avoid such damage

Were the blocks you snapped those cranks in all throwaways kev?

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[Maverick] 1971 Mini K

Only the 9000 rpm one, which was 1220cc with Imp 68.0mm pistons..
A circlip came out of an Imp piston and the gudgeon pin scored the bore 5/8" wide... ouch!

Usually on the small bores IF they go, they only crack the crank at one end or the other. Block is usually OK.

I drove the 850 5 miles home!...

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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.

hey kev i can sell ya a 998 with a gundgin polish on the bore
makka

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Anonymous moderation means the agro that is built up towards the mods isn't aimed at an individual (fewer "Makk" attacks). Less stress for mods means less moderator "retirements".

ouch alright..lol

well it looks likr if i go ahead with it, ill get it strengthened, or look out for one in better condition and get that strengthened like you said!

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[Maverick] 1971 Mini K

My 1100 natural aspiration is good for 7000 and on its 2nd rebuild showed no crank cracks No shot peening etc.
Still good for 7000.
Top khana engine.

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Dean Hutton's first car was a Mini.

Geez Tombo, you really dredged this one up from the past..
Yep, a well built and balanced 1100 (we can get 1188cc easy now with GR's +.100" pistons) is fine to 7000. With good torque too.
68mm Imp pistons are too hard to find now (and exxy) for GOOD (ie UK) ones.

If you are going to rev it, I'd try and get a 1098 crank that is still at standard size or -.010".
Crack test then regrind it if needed, making the corner radii as big as possible. Then balance it.

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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.