911 2.2S Engine Rebuild – Part 4: Cream-Crackered Crank!!!

Beautiful re-ground and polished short stroke crankshaft
Beautiful re-ground and polished short stroke crankshaft

Mon 16th September 2013

I’d had a call the previous week from Steve at Jaz to let me know that he’d had a blazing row with the company sorting out the cylinder heads. They’d had the heads since mid-July but still hadn’t started any work on them so Steve is going to have to take them back and give them to another company.

The 1st choice company was preferred as they make their own valve guides but the second company will do just as good a job provided Steve can persuade them to take on the extra work of fitting new Porsche valve guides.

The biggest drama came on Mon 16th Sep when Steve called to say that my crank was cream-crackered (cockney rhyming slang for knackered for non-UK readers). The different engineering company he uses for re-grinding and polishing cranks (who also do lots of work for the F1 teams) had finally gotten around to checking my crank only to find that one big end had been over ground (an off-set grind used for 2.4 cars) from 56.995 mm to 56.295 mm (the maximum factory recommended regrind for 2.2 cranks) BUT with the other big ends left at the standard dimension for 2.2. So in effect I’ve been driving a hybrid with 1 cylinder on the way to being wonky 2.4 spec and the remaining 5 cylinders as standard 2.2. Can I claim back congestion charges from Boris?

– Disaster!

Steve said he’d try to find a replacement 2.0 or 2.2 counter balanced crank (2.0 and 2.2 T cranks are not counter balanced) but these are now like hen’s teeth. He said I might need to go for a 2nd hand 2.4 crank which are more readily available. Not an ideal solution as with 2.4 rods – it makes it a full blown 2.4 long stroke engine which might have better overall performance but is not right for the car.

 

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