Scat Crank Dimensions??

[Tim Ayers]

Originally Posted by JSeery

Don't know about flathead, but in general on high performance engines, the smaller bearing diameters are desirable. The reason being the smaller diameter bearings has less drag. This mainly applies to main bearings, but would think the same reasoning would also apply to rod bearings. You wouldn't think there would be that much difference (and I'm sure there isn't!) but when you are attempting to get every last bit of hp out of an engine these things add up.

Makes sense. This may be a question for Pete, but I'm curious if anyone attempted to make a roller bearing mains/split crank set-up like an Miller/Offy engine?

To me, that seems like it would offer the least drag of any bearing set up.

[JSeery]

Originally Posted by Tim Ayers

Makes sense. This may be a question for Pete, but I'm curious if anyone attempted to make a roller bearing mains/split crank set-up like an Miller/Offy engine?

To me, that seems like it would offer the least drag of any bearing set up.

Not sure how big an issue it is until you get into the really high rpm ranges. We ran one of our overhead cam engines in the 9000 rpm range and it was capable of 12,000 rpm with the right components (way out of my price range!).

[Lawrie]

Kiwi,
how to the larger rods clear the bottom of the bore,no grinding?
You watch the all blacks last week.
Lawrie