Quote:
Originally Posted by 3MI Racing
Larger diameter also means a higher bearing speed and more friction and requires more oil flow. The EJ cranks are quite robust. I only know a handful of failed OEM cranks.
The EJ205/7 revised oiling crank, not shown above, I actually have guys spinning well north of 9k.
The crank was beefed up because with the tighter bore spacing of the block architecture, the crank had to be shortened. With the increased stroke to make up for reduced bore (see bore spacing) the bearing overlap was reduced, hence the increased bearing diameter. The throws are then thickened to further strengthen the crank and reduce flexure that comes with the increased stroke (as stroke is a moment arm) and the flexure also increases with cylinder pressure (more so acceleration rate of the piston).
I can go on but I think you have the idea  |
Interesting opinions here...
The bore spacing is the same as is the length of the crank.