Any one used the 1100 crank in a 1275 block ?

i was reading my manual the other day and noticed the 1100 crank has 2 mm extra stroke just wondering if you can use the crank rod setup out of 1100 to make stroker motor for 1275?

Any one done it or know any one that has done this?

The main bearing sizes are different on the 2 cranks. Most people offset grind the later big journal 1275 crank for a stroker motor.

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Steve

What he said. I just did one, got 84.3mm stroke out of it, still with standard size bearing shells. That's about 0.6mm more stroke than a Morris 1100 one.
You could get a little more stroke than this, if you're prepared to sacrifice crank life by grinding the crankpins even smaller to take undersize shells.

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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.

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No offence intended here but--> anyone writing a book about minis 30 years ago may not have experienced such worn or stuffed-with components as we are finding these days.

You should put your heart & soul into everything you do.

I thought of you Matt, but didn't say a word.
How is the world's supply of -.080" big end shells lately??

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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.

hee hee,,, i have one set in the 1510 donk now,,,gave a set to my dad,,,& have 2 more sets in the draw right beside me as i type,,,but i`d almost bet there are more around somewhere,,,probly people have them sitting in their shed somewhere & don`t even realize what they are or even that they`re there

that`s how i found the last 2 sets just kept plugging people for them

even Doug, who used to work for Mini Mania in the USA, said that they wouldn`t be able to be found anymore,,,GONE!!!,,,then i get this e-mail from him a few months later saying that they`d done a bit of a clean up & guess what was sitting on top of the bearing cupboard?,,,, yep a set of .080 unders & he reckoned that they`d have to have been sitting there , covered in 20 layers of dust, for over 15 years ,cause that`s how long he was working there for & no one knew they were even there.



gotta love the back yard sheds hey???

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No offence intended here but--> anyone writing a book about minis 30 years ago may not have experienced such worn or stuffed-with components as we are finding these days.

You should put your heart & soul into everything you do.

In that case Matt you should have a clean up over there.

You'll prolly end up with a wheelbarrow full of em






Aww heck, i'm in deep sh!t now!!!

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Metal to burn, sparks to fly...

Are the crank pin smaller or bigger on the 1100 if they are larger you could tunnell bore the main caps out to suit. any one got any info.

hey doc what are you talking about
which part of the engine is this?

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Inconspicuously Conspicuous
Appreciation without Depreciation
forever chasing clearer skies...

There is a 1098 block that will take an 1100S or Cooper S crank, it's a Sprite Mk2A..
2" mains in block already, but what's the point- it's still only a small bore and won't bore past 68mm.

Grab a 1275 block, there's still some about.
Boostedmini had one for sale for a coupla hundred$ recently, PM him.

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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.

I have quiet a few 1275 blocks

& the sprite (10cc as it`s known) block is the large journal block as Kev says, but it`s the crank that`s the problem,,,it`s a "North/South" crank , so the flange would have to be cut off & the stub pinned on,,,i don`t like doin it,,,many people have done it & some have failed & some are still ok,,,i`m not a fan of suspect stuff,,,rather do it right first time & have it last & last & last

one of my good friends up here in Brissy (Peter Tighe) has done a sprite with that donk, bored it out to 73mm (yes Kev, 73mm ) & fitted the 10cc crank & a supercharger & an alloy (mini gearbox modified) sump,,,pretty extensive work really,,,& you shoulkd see the bucket -o -puss sprite that it`s all fitted too,,,you wouldn`t expect it to have all that under the bonnet,,,tue sleeper

& metalFab,,,trust me,,,i`ve looked

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No offence intended here but--> anyone writing a book about minis 30 years ago may not have experienced such worn or stuffed-with components as we are finding these days.

You should put your heart & soul into everything you do.