SG or pilot shaft? That is the question--Q&A

Radio Control Car Action, Sep 2002 by Gonzalez, George M

I own an HPI RS4-2 and plan to get a new engine for it; I'm Novarossi RS 12 engine. After a bit of research, I found out that there are two types of crankshafts for it-SG and standard. What's the difference between these two types of crankshafts? The engine is also available with a slide carb or a rotary carb. Which version will fit my car without any modifications? [email]

Arel T. Z.

In SG-type engines, the pilot shaft is built into the end of the crankshaft, while standard engines have threaded crankshafts and require a clutch nut with a built-in pilot shaft. Only standard crankshaft engines can be installed in your vehicle, and HPI provides the clutch hardware for that installation. So stick to a standard crankshaft engine. Your vehicle comes with the necessary linkage to install both slide and rotary carburetors. Again, if you're looking for the simple way out, pick up the rotary-carb version.