What engine is this?

[Rc legend]

What is this nitro engine?

 

[cbaker65]

It appears to be an Ofna force engine,I don't know what size,however they make 28,21,18 an I think a 12 sizes.It being a 3.5,its probably a size Force 21

 

[Rc legend]

It appears to be an Ofna force engine,I don't know what size,however they make 28,21,18 an I think a 12 sizes.It being a 3.5,its probably a size Force 21

is it worth rebuilding or not?

 

[cbaker65]

is it worth rebuilding or not?

I don't think so,they were a common engine in the Ofna RTR's.
You can buy new economy engine for what it would cost to rebuild that one.
Probably for under $ 100. An I've seen them on ebay for about $ 70.00 bucks.

 

[ninnon]

is it worth rebuilding or not?

If you've got all the parts then why not, keep it as a backup

 

[Diesel3077]

Looks like the hpi 3.5