Onan P224 T260 NHC NHD NHE 2 Piston Gasket & Seal Kit 983cc

Complete top end rebuild kit for the Onan 60 cubic inch opposed twin. Two standard pistons with rings, both crankshaft seals, intake valve seals and the full engine gasket set. WHAT IS INCLUDED 2 x 112-0265 standard piston with ring set 2 x 113-0296 ring set, 5/64 inch compression 1 x 509-0040 front crankshaft seal 1 x 509-0041 rear crankshaft seal 2 x 110-3604 intake valve stem seal 1 x 168-0191 complete engine gasket set NOT INCLUDED - exhaust valve stem seals. The factory parts catalog does not list an exhaust valve stem seal for this engine, so no kit can legitimately supply one. Also not included: valves, guides or the governor shaft seal 509-0008, which is a separate part and is not a crankshaft seal despite often being bundled as though it were. SPECIFICATION Displacement - 60 cubic inches, 983cc Bore - 3.560 inch, 3-9/16 nominal Stroke - 3.00 inch Compression - 7.0 to 1 Configuration - L-head opposed twin, two cylinders FITMENT. P224G specs B, C and D. T260G on original pistons. NHC from spec D onward. NHD specs A through E. NHE specs D through H. WHAT THIS DOES NOT FIT. The early N series takes piston 112-0141 and a 3/32 inch ring set, 113-0312. That is a different piston, not simply a different ring, so this kit will not serve it. Later P224G engines from spec E onward, and later T260G pistons, run a .058 inch ring, 113-0311. IDENTIFY THE FAMILY BY HEAD BOLT COUNT. Ten bolts per cylinder head is this family and gasket set 168-0191. Nine bolts per head is the P216, P218 and P220, which use gasket set 168-0187. That single count separates the two families faster than any serial lookup. THE RING GROOVE. A nickel fits the top two grooves on 5/64 inch pistons. A penny fits the later .058 inch grooves. Because this kit supplies pistons and matched rings as a set, you are not fitting new rings to old pistons, so this is a confirmation rather than a decision. OVERSIZES, AND A NUMBERING TRAP. Pistons run 112-0265-05 for .005, -01 for .010, -02 for .020 and -03 for .030. The matching 113-0296 ring sets use a DIFFERENT suffix scheme: -05, then -10, -20 and -30 for the same three oversizes. The later 113-0311 sets go back to -01, -02, -03. Read the suffix carefully, because the schemes are not consistent with each other. There is no factory .040 piston for the P224G. AVAILABILITY. Gasket set 168-0191 is discontinued by the engine manufacturer. Do not substitute 168-0190, which covers head removal only. WHERE THESE ENGINES WENT. Generator sets, engine-driven welders, air compressors, pressure washers, portable sawmills, garden tractors and riding mowers, and truck-mounted cleaning units, across many equipment makes. Identify the engine by the model and spec plate on the engine itself rather than by the machine it powers. BEFORE ASSEMBLY. Measure bore taper and out-of-round. Check valve guides while the heads are off. Wash the cylinders in hot soapy water after any honing to carry out machining grit.

• WHAT IS IN THE BOX - Two 112-0265 standard pistons with 113-0296 ring sets, which is the 5/64 inch compression ring. One front crankshaft seal 509-0040 and one rear 509-0041. Two 110-3604 intake valve stem seals. One 168-0191 complete engine gasket set. NOT included - exhaust valve stem seals, because the factory parts catalog does not list one for this engine. If you have seen a kit claim them, that claim is wrong.
• COUNT THE HEAD BOLTS BEFORE YOU ORDER - TEN bolts per cylinder head is this engine family, and gasket set 168-0191 is the one that fits it. NINE bolts per head is the P216, P218 and P220 - a different engine that takes gasket set 168-0187, and nothing in this box will suit it. No tools needed for that check and it takes ten seconds.
• FITS THE 60 CUBIC INCH OPPOSED TWIN - 983cc, bore 3.560 inch which is 3-9/16 nominal, stroke 3.00 inch, 7.0 to 1 compression. P224G specs B, C and D. T260G on original pistons. NHC from spec D onward, NHD specs A through E, NHE specs D through H. NOT the early N series - that engine takes piston 112-0141 and a 3/32 inch ring, and it is a different part, not just a different ring.
• THE COIN TEST, AND WHY YOU MOSTLY DO NOT NEED IT - A nickel fits the top two piston grooves on 5/64 inch engines like this one. A penny fits the later .058 inch grooves. Because this kit supplies pistons AND matched rings together, you are not trying to marry new rings to your old pistons, so the groove question largely disappears. Run the test anyway as a family check.
• THE GASKET SET IS NO LONGER MANUFACTURED - 168-0191 has been discontinued by the engine manufacturer, so a complete kit like this is getting hard to assemble. Do not confuse it with 168-0190, which is the cylinder head removal set only and will leave you short. While the engine is open, check bore taper, valve guides and the governor shaft seal.