G'day guys and girls! I am currently in the process of rebuilding a 1275. The thing is I am putting a Cooper s crank in an 1100 s block I read somewhere, which I now cannot find, that 15 thou needed to be taken off standard thrust washers for it to work. So I have just picked up my thrust washers from the mechanic and he took 7.5 thou off each which would equal 15 thou. I have just started assembly and there is no end float at all...... was he suppose to take 15 of each washer which would equal 30 all up? This is what I am thinking which means I need to take them back to the mechanics.... which is in a different town :s

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1964 smooth roof panel van
1967 Mk 1 X-Police cooper s
1970 mini k
1975 leyland

I thought it was +30's when using 1100's in cooper s block so I assume it would be the opposite going the other way

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120bhp with 450kg just fun waiting to happen

We were prob. drunk when we set it up last and thought this will be a good idea

I run an S crank in an 1100S block, standard washers need approximately .015" taken off each washer.
Centre main web on an S block is 1/32" narrower than all other 1275 blocks.
Why??? No idea, except this makes the S crank webs 1/64" thicker, so it's stronger.

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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.

Hi Kev
Other way round 1100S have thicker webs.
Graham Russell

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"It's better to be not informed than ill-informed"

Big journal 1100S crank webs yeah I agree, because their conrods are narrower width.
Not so with small journal 1100S cranks which use S rods..

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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.

Well I took them to a mechanic to have ground down.i said I wanted 15thou off so he rang me back and said was that total so 7.5 thou off each to which he had done. I tested this and could only just get the 2 bottom washers in not the top and sliced my thumb open in the process. So I rang him and told him it was 15thou off each not 7.5. Just tried fitting them and I have 45 thou end float according to my dial indicator! So something's gone wrong.....really hoping to hurry up and get this built but things aren't looking good

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1964 smooth roof panel van
1967 Mk 1 X-Police cooper s
1970 mini k
1975 leyland

So if he already took 7.5 thou of and you told him you wanted 15 thou of, not 7.5.
I suspect he did what you said and took 15 thou off. Unfortunately they already had 7.5 thou off.
So the original 15 thou plus another 15 thou off each = 45 thou.

Looks like a simple communication error to me !

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Find a job you love and you will never have to go to work !

yep will need some more thrust washers and start again sadly

Well I was just on the phone to the mechanic and guess what the problem is I have a dial indicator that's measures in mm not inches! So I have double checked and I have 0.4 which equals nearly 16 thou...... so I need new ones and not as much taken off so instead of 15thou taken off I need 8 thou taken off each washer....... correct?

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1964 smooth roof panel van
1967 Mk 1 X-Police cooper s
1970 mini k
1975 leyland

Make sure it has at least .005" end float. The .003" in the books is NOT enough if you are going to rev past 6000.
I found this out the hard way. Oil pressure went South after 3 laps at Wakefield Park running .003". I now use .007".

Edit-
the crank webs flex and tear the bronze off the washers if too tight.

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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.

What happenes if youa have too much end float?

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1964 smooth roof panel van
1967 Mk 1 X-Police cooper s
1970 mini k
1975 leyland

Way too much, and they fall out.
I'd replace them once you get to .015", but that's nowhere near what's needed to drop one. Measure the step in the thrust face on cap or block. Get to that and they're gone.

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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.

No worries thanks doc for your input once again. I will get my bro to pick me up a new set at mini King tomorrow and get them ground with less taken off this time. So instead of 15 I'll get 7 or 8 thou off each. Cheers

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1964 smooth roof panel van
1967 Mk 1 X-Police cooper s
1970 mini k
1975 leyland

So went to build my motor and I didn't realise I need s rods as well because I have changed the crank. I already have my new pistons pushed onto 1100s rods....

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1964 smooth roof panel van
1967 Mk 1 X-Police cooper s
1970 mini k
1975 leyland

Ergh. God that sucks. Ah well, live and learn, keep on going and chalk it up to experience
(Yeah I didn't expect that to make you feel better, but in 3 months time it'll just be another war story about rebuilding the engine )

Sent from my Nexus 6P using Tapatalk

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