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12G1505 CRANKSHAFT ANOMALY

Posted: Mon May 27, 2024 5:09 pm
by Striped shirt
Hello all.

As I understand it, the 12G1505 crankshaft has rolled edges on the bearing surfaces, hence why they can be offset ground for long stroke using AEG S rods.
The CAM A+ crankshaft have grooved edges.
I have a 12G1595 crank that has grooved edges. It's a standard crankshaft.
Has anyone else ever seen this?? Could it just be a crossover anomaly?

Re: 12G1505 CRANKSHAFT ANOMALY

Posted: Tue May 28, 2024 9:57 pm
by Lakeland997
Just to clarify terms here, the A+ crankshaft has rolled fillet radii. The idea here is to prevent cracking at this most susceptible point and improve fatigue life.
These cranks are really pretty good. I have a SH Engineering one in my rally car that regularly revs to 8500 and a little higher occasionally.
The earlier (1275gt/1300) cranks would still have a fillet radii but it would have been machined not rolled. They may therefore have a reduced fatigue life but it does allow them to be offset ground (typically to deliver 1430cc) as you say.

Could you perhaps post an image of the fillet radii on your crank so that the experts on here can comment?

Andy