rustyrevo

Hi I have a new rb s3 conrod and wanted to know if it will work in my nova n21bf limited? thanks.

22Racer

iTrader: (67)

Rb's use a slightly bigger crank pin dia. so it would be a little loose on the Nova.

Rex

wingracer

iTrader: (24)

I don't think so but I could be wrong.

Nova rod lesson:

Nearly all Nova based .21 motors (including RB S, C and WS motors) use the R series rod, R1 through R7. They all have the same dimensions, higher numbers are just improved versions.

The exceptions:

1. I believe short stroke motors use a different rod and I believe the BF21 is one of those, not sure though as I have never had one of their short stroke versions.

2. Smaller crank pin motors. These are mainly onroad motors though I think they did try this on one of the high end offroad motors too. This would be the Collari edition and Cordoba motors (4.5mm crank pin) that use C series rods and the 353 (4mm crank pin) that uses a P series rod. These are the same length as the R rods, they just have a smaller lower rod bushing for the smaller crank pins.

Davidka

iTrader: (86)

Up until 2 years ago, RB engines had different crank pin sizes than most all others. I think it was smaller to reduce bearing surface speed. I don't know whether or not they changed, 2 years ago was the last time I heard it mentioned.

phoenix357

bf 21 uses a r7

wingracer

iTrader: (24)

If that's true, an RB S whatever rod should work just fine. I would break out the calipers and check it first just to be sure though.