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crank end float

bob dunn

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Mmmm - 4mm is a lot - approx 160 thou, and 2 orders of magnitude out of tolerance! (which I think is 4 to 10 thouish).

Your crank and block are officially 'thrusted' and I only know of 2 solutions; one is GT6 David's above and the other involves machining and expense. A machine shop can reshape and finish the end of the crank to a smooth square surface, then machine the mating section of the block to receive a custom made phospur-bronze thrust washer. This is usually pinned into place on little indexing pegs to avoid the problem that got you to this situation in the first place - spinning of the original thrust washer.

Its a faff, and costs, but on rare/valuable/sentimental engines its worth doing and gives the crank/block a new lease of life.

Sorry to bear bad news ;(


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Bob, you thinking of fitting a thrust to end cap, as well as the housing.
so having 2 , facing,and rubbing together,  !!!!

when you say you got 4 mm, is that wid the thrusts in or out, !!!

what ever you doo, try and use diff sized thrusts,
IE, if its 10 thou, then use a  standard and a 10 size,   [ nstead of 2   5,s or what ever you can get,]
BUTT, put the thickest  10,  on the clutch side, as this is where all the thrust comes frae, follow.!!

good luck   M

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If fitting a thrust  to the cap it should be arranged so that both it and the thrust on the block share the load. However unless there is a special reason to save this crank and block; the better course it to do as David suggests and replace them.
                                                                               Good luck,

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the orig thrusts are held/ arrested from rotation by lugs on the main brg cap, if the float is excessive these can get worn off by contact of the crank. you can with care and not too much heat  build up weld and fettle a new lug to replace the bits that  got worn off,

if the crank has contacted the block it it likley to need a metal spray( or similar) to build up enough to enable  regrind to reform/size the  crank journal thrust face

but this reclaims a disaster


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Hello Bob,

I'd say your two options are to take it to an engineering machine shop (not engine building machine shop) and see how feasible it is to machine and fit an insert or find another block and rebore it then fit your internals from the original engine. I suspect the latter may be the cheaper


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           Give yourself an upgrade..........One of the guy's with a hurricane on the sideways forum has this Engine:


It didn't sell at £60, it's a small crank so will go better than your last engine. This will be cheaper than anything else you can come up with and might even run as is???

Just a thought.....


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