What's New with the Nissan K21 Engine?
The New Nissan K21 Engine
The Nissan K21 has been restructured and there’s a lot of new tips and data you cannot afford to miss. For example, Nissan enables its new K21 engine as a 2.0-liter liquid-propane-gas or gasoline-powered four-cylinder engine. This is an engine you can find in the LX-series forklifts of Nissan.
What you may have also missed is the fact that the LX is considered to be a smaller, a bit inferior hauler version of a forklift that’s made to transport palletized cargo in the weight range of around 1,500 and 3,000 pounds. There are more clarifications like this here, and so let this article offer you both the essentials and nuanced information about the Nissan K21 Engine.
Another important description about K21 is that it is the only forklift type being used in 2,500 pounds or anything lower. Anything beyond that, such as weight load of about 2.5-liter or 3.3-liter diesel, should use a heavier-duty variant forklift, preferably a K25.
When the K21 received structural changes from Nissan to replace its current 2,065 cc design, its essential parts have been upended, too. One of the primary parts that received reformatting would be the fact that the new design now comes with a carburetor or electronic fuel injection. This addition enables the K21 to produce about 46.23 horsepower at 2,200 rpm rate.
You may easily expect that this new design will have a 116 pounds of torque even at around 1,600 rpm. With the fuel-injected K21, the engine can produce as much as 60.1 horsepower at 2,700 rpm and 118 foot-pound torque even when the range can reach as high as 2,000 rpm. That said, you can see the K21 already being used in the following models: PL01A, FL01A, UL02A, YL02A, and Lo1A forklifts and many other variants.
The new K21 would now always have the 3.5-inch bore and 3.27-inch stroke. Such design has also given the engine a two-valve cylinder head with bathtub-shaped combustion chambers that give it an even more powerful performance boost. The 1-3-4-2 firing order here that’s ingrained into the piston closest to the water pump would also now be installed with a number 1 classification. It must be added that the new K21 would measure 28.85 inches long, 22.16 inches wide and 29.25 inches high, with the engine weighing about 304.24 pounds dry.
The good thing, too, about this new classification is that it doesn’t include counting water in the cooling system or even the four quarts of 10W-30 oil in the engine’s filter and oil pan. Incidentally, you can expect that this new engine’s compression ratio now has a variety of fuel-type. The first type of compression ratio is a gasoline-powered engine with 8.7-to-1 compression rations. The LPG engines types would have to be about 9.3-to-1 compression ratio. Lastly, the gasoline-type engines would require about 89 octanes or greater. On the other hand, LPG engines of this type would need about 30P or higher in areas where the seasons are generally colder.
Cam Timing Specifics
You should know that the new K21s today, whatever the fuel type, would be using the same cam timing, as well as idle and ignition settings. Intake valves from this engine type would in default be opened at around 14 degrees before its specified top-dead-center.
Closed at around 30 degrees after bottom-dead-center, the exhaust valves of the K21 would be opened at around 32 degrees before the bottom-dead-center, at the same time it would be closed at 12 degrees after the top-dead-center. In terms of clearance, you can expect that there’s around 0.015 inch of clearance between the valve heads and the piston crown when the engine is particularly hot.
Timing and RPM Specs
It’s important to establish here that the K21 ignition has now set itself apart by being installed with a default stock of an exactly zero advance or retard; in other words, zero degrees BTDC. The reputation of K21 has been made even more superior because it has set its standard idle speed at 700 rpm. If it’s idle the K21 could go so far at 2,700 rpm, which is what also happens in a high-idle mode.
Trusting this engine for long-lasting and heavy-duty performance is no problem, too, since the K21 is now idle to run at 3,000 rpm under continuous load. The no-load rpm can even be governed to as high as 3,600 rpm. The new mechanism in this engine renders power from the engine’s crankshaft to its hydraulic pumps through a silent-drive chain.
Specialty Tools Tips
Maintenance of this K21 engine requires just as much specialized attention as in learning its basic and timing specs. This means you’d have to avail of a variety of specialty tools to service your K21 engine, which fortunately you can easily acquire through any reliable forklift dealer or through Nissan itself. Some of these powerful and yet necessary tools include a pulley puller (the No. KV11103000); what is called an engine attachment tool (No. ST05240001); an engine stand assembly (No. ST0501S000); and a crankshaft main bearing cap puller with two adapters (No. KV101041S0). You may also find a great use for a valve lifter (No. ST12070000) and a valve guide reamer set that has a 7.00 mm reamer (No. ST1102S000) to maintain your K21 engine at top condition.
Another specialty tool required for K21 engines would be an oxygen sensor socket (No. KV10113700) and a front and rear oil seal drift rod (No. ST1524S000 and No. KV10105500, respectively), which also goes well with an oil seal drift rod (No.ST15243000) specialty tool to keep the K21 engine always in its top shape.