the loader currently has what looks like a 336 in it, I've got about 30 4bt cummins some with sae bellhousings already, just wondering if anyone knew if the original flywheel would bolt to the 4bt or if not what other options I had without going back to a case engine, the original block self vented on both sides and would make a good bird house.
I can not answer your flywheel question, but here is a link to another thread with pictures. It appears someone swapped out a Case 301bd for a Perkins in a trackloader. HeavyEquipmentForums
Ask a machine shop about machining the Case flywheel to fit the 4BT crank. (I think that both are internally balanced, no balance weight on the flywheel) It might take an intermediate piece to make up distance.
You will have some homework to do. That flywheel on a 336 will have several differences, starter ring teeth is 137, thickness, center boss for the converter will all have to be worked out. I also think the common 4-390 run around 159 starter ring teeth. I would first get the engine and trans out of your w14 so measurements can be made. I would also talk with a Allison trans dealer, they should have the info as well as a good cummins dealer on what it takes to bolt up to a Allison series. They can take the tag info on the trans and match what you would need. I have seen around 20 machines that have been changed out to the 4-390 engine in different machines. The W14 is rated with the 336bd engine, rated horsepower at SAE net of 82 at 2200 rpm. The newer W14B and C went to the 6-590 and 6T with a clark 18000 series trans.
I swapped a 6bt Cummins in a Case W24c, it also had a Allison trans in it, I used a Flywheel from a Case 1845 skid steer (4bt) and had a .460 thou spacer made, the 1845 flywheel had the rite bolt pattern for the Allison drive plate it bolted rite up