Nissan K21 Engine Specsby Richard Rowe
Nissan used its "K21" engine -- a 2.0-liter liquid-propane-gas- or gasoline-powered four-cylinder engine -- in a number of its LX-series forklifts. The LX was a fairly small hauler, designed to move palletized cargo weighing between 1,500 and 3,000 pounds. The K21 was used only for forklifts rated at 2,500 pounds and lower; heavier-duty variants got the 2.5-liter K25 or a 3.3-liter diesel.
Description and Applications
The K21 displaced 2,065 cc. It came with either a carburetor or electronic fuel injection -- referred to in Nissan nomenclature as ECCS, or "electronic concentrated control system". The carbureted K21 produced 46.23 horsepower at 2,200 rpm and 116 foot-pounds of torque at 1,600 rpm. The fuel-injected K21 produced 60.1 horsepower at 2,700 rpm and 118 foot-poundst of torque at 2,000 rpm. The K21 was used in L01A, PL01A, FL01A, UL02A and YL02A forklifts and all of their variants.
All K21s had a 3.5-inch bore and 3.27-inch stroke, a two-valve cylinder head with bathtub-shaped combustion chambers, a 1-3-4-2 firing order -- with the piston closest to the water pump being number 1. The K21 engine measured 28.85 inches long, 22.16 inches wide and 29.25 inches high; the engine weighed 304.24 pounds dry -- without counting water in the cooling system or the four quarts of 10W-30 oil in its oil pan and filter. Compression ratio varied by fuel type: gasoline-powered engines have 8.7-to-1 compression ratios and LPG engines have 9.3-to-1 compression ratios. Gasoline engines required 89 octane or greater; LPG engines required 30P or higher in colder seasons.
Cam Timing Specs
All K21s, regardless of fuel type, used the same cam timing, idle and ignition settings. The intake valves opened at 14 degrees before top-dead-center and closed at 30 degrees after bottom-dead-center; exhaust valves opened 32 degrees before bottom-dead-center and closed 12 degrees after top-dead-center. There was 0.015 inch of clearance between the valve heads and the piston crown while the engine is hot.
Timing and RPM Specs
The K21 ignition came stock with exactly zero advance or retard -- zero degrees BTDC. Nissan set the standard idle speed at 700 rpm, but the K21 could idle at 2,700 rpm when in high-idle mode. The K21 could run at 3,000 rpm under continuous load; no-load rpm was governed at 3,600 rpm. Power made its way from the engine's crankshaft to the hydraulic pumps via a silent-drive chain.
You'll need a number of specialty tools to service the K21, all of which are available through Nissan or your forklift dealer. They include a pulley puller, No. KV11103000; an engine attachment tool, No. ST05240001; an engine stand assembly, No. ST0501S000; a crankshaft main bearing cap puller with two adapters, No. KV101041S0; a valve lifter. No. ST12070000; a valve guide reamer set with 7.00 mm reamer, No. ST1102S000; an oxygen sensor socket, No. KV10113700; a front and rear oil seal drift rod, No. ST1524S000 and No. KV10105500, respectively; and an oil seal drift rod, No.ST15243000.
Richard Rowe has been writing professionally since 2007, specializing in automotive topics. He has worked as a tractor-trailer driver and mechanic, a rigger at a fire engine factory and as a race-car driver and builder. Rowe studied engineering, philosophy and American literature at Central Florida Community College.