Originally Posted by
1QwkSport2.5r
The two crankshaft types are really only tied to whether it's a pullstart engine or not. An SG shaft won't have a pullstart (closed backplate) and a IPS shaft engine will. IPS is Traxxas' abbreviation for Integrated Pilot Shaft which just means it has the little nub on the crankpin for the one-way clutch to drive the crank.
Ive be seen some engines with a longer crankshaft output than others which can require cutting the end of the shaft off. Likely this is not the issue here. It sounds to me the OP removed the tapered collet before installing the flywheel.
The shaft type has nothing to do with having a pull start or not, there are both pull start and non pull start versions of the different crankshaft types.
A standard crank is completely threaded at the end and the pilot shaft for the clutch is integrated into the clutch nut. These are available in either short shaft or long shaft versions and are most common on small blocks.
An SG crank has the pilot shaft for the clutch integrated into the crank shaft and has a threaded hole in the end for the clutch bell retaining screw. This is most common on big blocks.
An IPS crank is basically the same as an SG crank but it also has a groove on the end for an e-clip to hold the clutch bell on. It still has the threaded hole in the end like the SG crank though. This is most common on Traxxas engines.
Then to be really confusing, most people call the IPS/SG type shaft a pilot shaft crank, but I have seen others call a standard shaft crank a pilot shaft crank, although I have no idea why.
There are also universal shaft/multi shaft cranks which can be either type with an adapter.