Anthoop

Does the end of the crankshaft on the new engine look the same as the old engine?......there are two types of crankshaft....pilot and SG.

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.

krokodyl

Ok so i got the engine started today!! It idled nicely and so far im happy with it. It drank the fuel in over 15 mins but i guess thats fine since its very rich, fuel was flyin out of the exhaust. It took FOREVER to get the gear mesh right because the engine pullstart was bigger and naturly the pull start was facing the other direction. This means the fuel tank wouldn't allow the engine to move much. But i finally got it going.

Anthoop

Tim- Maybe I used the wrong terminology after looking into it...what I was meaning was the different crank types where the clutch is...when OP said he had a hub on the crank that he removed I was thinking he had the wrong crank type...pictures will possibly explain better (had a few drinks now)...

1QwkSport2.5r

Ah yes... Those dreaded prop hubs.. Usually you don't see them come on car engines.. Then again, I don't buy OS, so I don't know what they come setup with.

robwiljas

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.

Anthoop

Now you have put a spanner in the works Rob....

Looking at the pictures I put up there...I have always called the one on the left a pilot shaft...and the right SG.

Now I know (after searching) that is incorrect terminology but you can see the reasoning there....the left hand engine needs an extra piece (pilot shaft) to use a clutch/flywheel....

Just another thing of confusion in the RC world...and we are only talking about a crank shaft...

robwiljas

Yeah I guess that makes sense. I've always considered the SG/IPS type as a pilot shaft crank since the pilot shaft is part of the crank shaft. Most manufacturers do the same but I have seen some refer to the standard shaft as a pilot shaft crank.