Onan Rings Gaskets Seals Kit P224 T260 NHC 113-0296 Set

Piston ring set, complete gasket set, crankshaft seals and valve seals for the Onan 3-9/16 inch bore twin. IN THE KIT Ring set - Onan 113-0296, 5/64 inch compression ring Complete gasket set Crankshaft seals - 509-0040 front, 509-0041 rear Valve stem seals THE ENGINES. P224, T260, NH and NHC - all 3-9/16 inch bore, 3.000 inch stroke, 60 cubic inches. Onan's own spec sheets round the bore to 3.560 inch; the machining spec is 3.5625 to 3.5635. NOW READ YOUR SPEC LETTER. This is the part that matters, and it is the reason this page has to narrow its claim rather than widen it. Onan used THREE different ring sets on this one bore and split them by engine spec letter rather than by horsepower or by model: 113-0312 - 3/32 inch compression ring - early N series, NHC and NHCV specs A to C 113-0296 - 5/64 inch compression ring - P224G specs B, C and D; T260G on original pistons; NHC from spec D; NHD specs A to E; NHE specs D to H - THIS KIT 113-0311 - .058 inch compression ring - P224G from spec E; later T260G pistons; NHE from spec J; NHM from spec C The spec letter is stamped on the engine nameplate next to the model number. THE COIN TEST. If the engine is already apart, a nickel fits the top two piston grooves on the 113-0296 engines and a penny fits on the 113-0311 engines. COUNT YOUR HEAD BOLTS. Ten per head is this family, on gasket set 168-0191. Nine per head is the smaller P216, P218 and P220 family, a 3.250 inch bore engine on gasket set 168-0187 - a completely different kit. Note that the valve stem seals are not part of Onan's own gasket set. They are added here because the job wants them.

• WHAT IS IN THE KIT - Ring set, Onan 113-0296, which is the 5/64 inch compression ring set. Complete gasket set with crankshaft seals 509-0040 front and 509-0041 rear. Valve stem seals. Everything for a ring and reseal job on the 3-9/16 inch bore Onan big block twin.
• READ YOUR SPEC LETTER - ONAN SPLIT THESE BY SPEC, NOT BY HORSEPOWER - This kit ships 113-0296 and that covers P224G specs B, C and D, the T260G on original pistons, NHC from spec D onward, NHD specs A through E and NHE specs D through H. The spec letter is on the engine nameplate beside the model number and it is the check almost nobody knows to make.
• WHICH ENGINES THIS KIT DOES NOT COVER - Early N series and NHC or NHCV on specs A, B and C take ring set 113-0312, the 3/32 inch ring. P224G from spec E onward, and later T260G pistons, take 113-0311, the .058 inch ring. Neither is in this kit. Same bore on all of them - the difference is ring thickness, not diameter.
• THE COIN TEST IF YOU HAVE THE ENGINE OPEN - Onan split these sets by compression ring thickness. A nickel fits the top two piston grooves on the 113-0296 engines, which is this kit. A penny fits on the 113-0311 engines, which is not. It is a crude check and it works.
• COUNT YOUR HEAD BOLTS TO CONFIRM THE FAMILY - Ten head bolts per head is this engine, the 3-9/16 inch bore 60 cubic inch twin, gasket set 168-0191. Nine head bolts per head is the smaller P216, P218 and P220 family, a 3.250 inch bore engine on gasket set 168-0187, and nothing in this kit suits it. Count them before you order.