The IRL motors have a smaller rod journal. I think the Hondas are 1.88 versus 2" for a small journal Chevy and a 2.1" diameter for the large journal small block Chevy.

The smaller journal diameter is just doing 2 things, less bearing speed/friction and less overall weight (both the rood itself and the crankshaft of course).

I believe some pro stockers go as small as 1.772 lol !!


But the "Honda rod journal" is a real common size. Just last week we had a stock car engine with an Eagle lighweight crank with Honda rod journal size instead of 2" or 2.1" diameter rod journals. This very crankshaft goes in a SBC with crazy rules that make them have to pull 17" of vacuum at idle, have to run cast iron heads ect, lol. Neat stuff to find buried in an all steel small block covered in mud.

 

good to know graham

 

Thanks graham