Rod Journal Size

Curious as to the benefits of going to the 2.20 rod journals vs the standard 2.375

My thoughts, feel free to correct me if I'm wrong.
Less block clearancing
Lighter rod?
less bearing surface = less friction (free's up some HP?), but since there's less bearing surface is that harder on the bearings?


Engine I will be looking to build is a race motor and I'm looking to make 625-650 HP.

Lower journal overlap means slightly weaker crank (still safe).
Smaller journal means slightly reduced local oil pressure, which is a function of circumference × engine speed (still safe).

Unless you are burning fuel, there is never a reason to use a 2.375 rod throw. 2.20 is plenty big. 2.100 is more than doable most of the time N/A.

BTW, the smaller rod throw also reduces the weight of the rod, the rod bearing and the rod throw.

I agree, late SBC 2.100" is safe with any conventional stroke, but there are fewer rod choices by length than with BBC.
Caveat: if the grinding doesn't unmask an oil passage.