Hi knowledgeable mini experts,

I have a crank that I would like another (or multiple!) opinions on. I think it will clean up ok at 10/10 but would like a more informed opinion. The crank is a large journal 1100S crank (12G1505).

The following measurements are averages (from 3 measurments) from around the jounals / mains and are as follows:

Front main: 1.991"
Centre main: 1.992"
Rear main: 1.992"

Journal cyl numbers:
#4: 1.741"
#3: 1.742"
#2: 1.740"
#1: 1.740"

The reason I ask is this is the better of the two cranks I have.

Cheers, Nick

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"In two years time your car will be like a lady's clothes, out of date, my car will still be in fashion when I am dead" - Sir Alec speaking to Pininfarina

I doubt it will clean up at -.010", as the wear on the mains won't be even when it's put between centres. And 2 crankpins are at -.010" already.
You can get the machinist to try for it, but I reckon it'll be a -.020"/-.020".

<edit> you could grind the crankpins down to 1.625" (std S), and use S rods.
This gives you the option to stroke or destroke it if you want.

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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 Kev

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"In two years time your car will be like a lady's clothes, out of date, my car will still be in fashion when I am dead" - Sir Alec speaking to Pininfarina

Std mains 2.005/2.001
Std B/E 1.7504/1.7509

Your crank is allready 0.10 undersize on the B/E and mains. You will need to go to 0.20. If the journals are badly scored you may need to go more, Let the crank grinder decide. You also have the option to grind the B/E down to 1.625 and use S rods, that way you can stroke/destroke to suit your requirements. But you may find that the crank is cracked and then you can use it to hold the shed door open!

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Have a Nice Day.
If already having a nice day please disregard.

Many of these old cranks are cracked, so check that first before spending time and $$.

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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.

On monday it is off to get crack tested so I know, at worst I've only wasted a small amount of money on a door stop

I hit one of the webs with a hammer and it rings like a bell. I have heard off of someone that it is more likely to be a good'un if it does that. I might just have to go to plan B and use the other crank if this one is stuffed

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"In two years time your car will be like a lady's clothes, out of date, my car will still be in fashion when I am dead" - Sir Alec speaking to Pininfarina

Yes, giving a crank a tap is a good way to tell if there cracked, if they ring there usually ok, if the "thud" then you may have a crack, but allways get them tested, along with the rods (as rods crack too!)
And it seems Kev can type faster than me!

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Have a Nice Day.
If already having a nice day please disregard.

He has had more practice.

I've been thinking about this...can any of you give me a price on how much extra it costs to stroke one of these cranks. I'm already planning on getting it wedged as well as getting the journals and mains ground 0.020" under.

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"In two years time your car will be like a lady's clothes, out of date, my car will still be in fashion when I am dead" - Sir Alec speaking to Pininfarina

When I got mine done 12 months ago by St George Crankshafts, it was $100 extra to stroke it.
A straight regrind to next size under was $140.
To also stroke it the cost was $240 total.

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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.

You just can't fault Spiro and close to home

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Stop Licking the Dog...I Don't Care Who Started It

Thanks guys. If it's only that much extra why not, even if it is only a couple of mm extra.

Just have to track down some S rods before I start the rebuild.

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"In two years time your car will be like a lady's clothes, out of date, my car will still be in fashion when I am dead" - Sir Alec speaking to Pininfarina

Kev, when Spiro strokes these cranks, does he widen the journal to take the S rod or leave it std width?

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Steve

Usually Spiro leaves the journal width stock, and GR narrows the S rods.
IMO widening the journal will thin the webs and could weaken the crank. But I know some have done this......

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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 would also get the crank hardened if i were you

we have them ground to just "above" what we actually want to end up with, (maybe 2 or 3 thou above)

then balance them to take off any large chunks (if there is in fact any large chunks needed to come off it)

then we harden them,,, this process can bend them a tad (sometimes,,,sometimes not) & they also grow bigger in the process... we make sure the crank gets placed in the middle of the tank & leave it in there all weekend for most fullest hardening

then we grind them true to the sizes we want (often only taking a wisker off them)

& then we balance them again

so,,, all up the process is a bit lengthy,,,, & a tad more expensive then the "Average" way of doing them,,, but none of our cranks have broken doing things this way since 1969

& of course now that i`ve said that we will have a bout of broken cranks happen yeah?

There is also a "Cryo" hardening treatment out now,,, i believe it doesn`t bend the cranks as much as Nitriding

& yes just narrow the "S" rods 15thou per side is fine

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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.