4HP crank in a Raptor?

Thomas1971

Thomas1971

Member
I heard you can run a 4HP crank in a Raptor. It’s a shorter stroke (2.5”), so you need a long rod with stock Raptor piston. I just can’t figure out which rod I need? From my calculations the closest rod would be 3.88”. But that would give me 0.0365” of piston out the bore?
Any input on this would be nice.
Just seeing if I can piece something together for fun.
 
2.5 is not shorter.
Stock stroke on a 5HP flathead is 2.437."

IIRC, the 4HP engines I have worked on used the same crank, but smaller bore. I have one here in the shop currently.


-----
🏁Thanks and God bless,
Brian Carlson
Carlson Racing Engines
Vector Cutz
www.CarlsonMotorsports.com
Carlson Motorsports on Facebook
33 years of service to the karting industry ~ 1Cor 9:24
Linden, IN
765-339-4407
bcarlson@CarlsonMotorsports.com
 
The short stroke 4 hp crank is used to slow 5hp Jr Dragster motors down. So it's going to slow down a 5hp down not make power just saying.
 
You must log in or register to reply here.
Back
Top