I have five Perkins engines in the shop. Two are T4.236, (LJ, turbocharged) two are 4.236, (LD, natural), and the one in my Hyster forklift is a 4.248.2, (LG, natural) One of the turbocharged engines is a "stress block" configuration originally from a Cat 436 TLB. I rebuilt this one complete with OEM Perkins parts and the owner defaulted so I wasn't going to let the engine go. After two full years, I kinda figure it's time to do something with it as they scrapped the tractor. The others are forklift engines originally. My question is this: Are the oiling systems the same in these engines internally? The engine from the TLB has a thickened and drilled boss cast into the block for the turbocharger return oil. The others do not. None of the engines have piston cooling jets. I want to make use of one of these engines in a project but the stress block configuration is of no use to me. I could easily sell, or break it apart and build one of the forklift engines into a turbocharged variant if the oiling system can be completed. I've looked at the block thickness in the area the return oil line attachment point and I really don't want to drill and tap the block without this thickening. If the pressure side of the oiling system is the same between the engines, I can come up with something to facilitate drainback into the pan if need be.
I thought the 248 was basically a bored out 236 with the same 5" stroke.
They are very much the same with a larger bore and a different type head gasket and piston crown. Perkins called this a "Squish Lip" design.