SBF Boosted Rod Ratio

[Bad Notch]

Hi guys

Looking to convert an already assembled nitrous engine into a blower motor. 9.5 SBF. 4.0 x 4.125

Possible issue at hand :

6.250 Rod ( Callies Ultra I beam )

2" Crank Journal ( Callies Magnum )

Its going to be an E85 Engine. I plan to have the compression between 10.5 and 11.5 and turn 8000 - 8300 RPM - HP Level 1500 ~

Is that long rod and small journal going to pose a issue getting this done ?

[Mark O'Neal]

No.
Use whatever gives you the best pistons layout.

[Mark O'Neal]

No.
Use whatever gives you the best piston layout.

[Keith Morganstein]

The rod to stroke ratio of 1.51 isn’t bad. I wouldn’t expect issues from that.

A bigger concern may be crank strength with a 2” journal at that stroke (not much overlap)
However, you’re using a good crank and rods, so it’s something I would attempt already having the parts.
Since the parts have been used and maybe hard, I’d want to mag everything to check for cracks.

Aftermarket block I hope?

[piston guy]

It's only a slight change from a STOCK 454 Chevy. No big deal , run it

[Bad Notch]

Thanks for all the help guys. Much appreciated !

[Bad Notch]

The rod to stroke ratio of 1.51 isn’t bad. I wouldn’t expect issues from that.

A bigger concern may be crank strength with a 2” journal at that stroke (not much overlap)
However, you’re using a good crank and rods, so it’s something I would attempt already having the parts.
Since the parts have been used and maybe hard, I’d want to mag everything to check for cracks.

Aftermarket block I hope?

Everything is brand new un used. Block is a Dart Iron Eagle.

[Mark O'Neal]

The correct rod to crank ratio is 8:1

Rod ratio is irrelevant.