What's the difference between an OS SF engine and an FP?
 

I have a bunch of engines that I have collected through the years and I am trying to decide which one to put in the D-7 I'm building. The SF .40 has a big case-same size as an OS .46FX, The Fp has a smaller case but with the same displacement. Are the Sf's more powerful than the FP's or just bigger?

RE: What's the difference between an OS SF engine and an FP?
 

The SF engines have ball bearing supported crankshafts, while the FP's have bushings. The FP is a good line, but the FP 40 will not have as much power as the SF 40. Also, the SF has a two-needle carb while the FP uses an air bleed carb. The two-needle is a much better carb.

Sandy T

RE: What's the difference between an OS SF engine and an FP?
 

I have a .45-46? SF that is pulling great after 10+ years of abuse and neglect. I know that dosen't speak to your power question. But it's a great engine, starts right up and goes.

RE: What's the difference between an OS SF engine and an FP?
 

The SF was a predecessor to the FX and then the AX

The FP was a predecessor to the LA

RE: What's the difference between an OS SF engine and an FP?
 

Whats the difference?

About 6yrs--ball bearings--and $20. [sm=lol.gif]