Nitrided, 84mm stroke, cross drilled 1.625" "S" big end journal; for 1300 block.
Forged EN40B steel nitrided cranks are considered the ultimate in specification, even over the "billet" type. This is mainly because the grain pattern of a forging follows the shape of the webs and bearings whereas the billet type is machined across the grain. We stock all the forged types as well as re-stroked standard material cranks and new cranks. All are cross-drilled, except C-AEG601/2, and heat treated for maximum durability. All are machined to fit 1275/1300 non-S center main except C-AEG479 which is "S".

Forged EN40B steel crank

for the 1300 solid wall block with the main width of 1.211" but has 1.625" big end journals sizes as per the original Cooper S.

All cranks have been re drawn to benefit from latest technology by having the larger crank webs designed to reduce whip and resistance at high revs giving smoother running and easier balancing, plus being mass centre balanced.

The bored holes for the big ends reduces weight of the crank and does not require drilling through the largecounterr balance C shape webs

Nitrided, 76mm stroke, 1.625" "S" big end journal, for 1275/1300 non-S block.
Forged EN40B steel nitrided cranks are considered the ultimate in specification, even over the "billet" type. This is mainly because the grain pattern of a forging follows the shape of the webs and bearings whereas the billet type is machined across the grain. We stock all the forged types as well as re-stroked standard material cranks and new cranks. All are cross-drilled, except C-AEG601/2, and heat treated for maximum durability. All are machined to fit 1275/1300 non-S center main except C-AEG479 which is "S".