new Lifan NRF200 4-valve engine

Discoveror · 01-28-2023, 02:14 PM

Is (when?) Lifan bringing their new 4-valve, high-compression, liquid-cooled engine to America, this year?

I think this is an especially nice engine design:

4-valves yield better combustion chamber cross-flow breathing for more power & torque from a given displacement
11:1 compression ratio makes more power and torque than the lower compression ratios, needed for air-cooled engine longevity
liquid cooling brings more stable temperatures, allowing more ignition advance, again for more torque & power

The only thing missing is horizontal orientation - for lower center of gravity; this engine is, apparently, designed for vertical deployment. A gas tank atop a vertical engine doesn't help lower center of gravity.

Lifan claims 15 kw @ 9000 rpm (15 kw / .74 = 20.27 bhp) and 17.5 nm @ 7500 rpm (17.5 nm * .74 = 12.95 ft-lbs of torque) - not bad from 200 cc (not 250 cc or 300 cc). In fact, those power & torque numbers are right up there with and FAR more efficient than Lifan's own KPX250 cc air-cooled engine. However, the torque is a bit less than Lifan's 250 cc air-cooled engine (12.95 vs. 15.1 ft-lbs); nothing make torque like cubic inches.

Given the YT videos, I've seen, showing the 125 cc Honda mini's on dirt, it seems like 10 - 15 hp is sufficient for exploring off-road (KPM offerings notwithstanding). Is it true (I saw on some YT video) that Lifan is/was making some engines for Honda?

I suspect that this will make a Great world-engine design which Lifan can deploy in sport, cafe and dual-sport bikes. I suspect that Lifan will see widespread (world-wide) demand for this strong 200 cc engine?

The cafe and sport bikes, using this new engine, on the Lifan world site are spec'd at 152 kg (152 kg * 2.2 lbs/kg = ~333 pounds). 333 pounds seems to be nearly as light as manufacturers can make a liquid-cooled bike; the Kawasaki KLX300, liquid-cooled is said to weigh ~302 pounds (wet); the Honda CRF300L, also liquid-cooled is 306 pounds (wet); the CRF300Rally with a bigger tank, more fairings and a wind-screen is right up around 333 pounds, too. 333 pounds might be liftable and 'flickable' off paved roads?

01-28-2023, 02:14 PM	#1
Discoveror Join Date: Nov 2022 Location: Wyoming Posts: 87	new Lifan NRF200 4-valve engine Is (when?) Lifan bringing their new 4-valve, high-compression, liquid-cooled engine to America, this year? I think this is an especially nice engine design: 4-valves yield better combustion chamber cross-flow breathing for more power & torque from a given displacement 11:1 compression ratio makes more power and torque than the lower compression ratios, needed for air-cooled engine longevity liquid cooling brings more stable temperatures, allowing more ignition advance, again for more torque & power The only thing *missing is horizontal* orientation - for lower center of gravity; this engine is, apparently, designed for vertical deployment. A gas tank atop a vertical engine doesn't help lower center of gravity. Lifan claims 15 kw @ 9000 rpm (15 kw / .74 = 20.27 bhp*) and 17.5 nm @ 7500 rpm (17.5 nm .74 = 12.95 ft-lbs of torque) - not bad from 200 cc (not 250 cc or 300 cc). In fact, those power & torque numbers are right up there with and FAR more efficient than Lifan's own KPX250 cc air-cooled engine. However, the torque is a bit less than Lifan's 250 cc air-cooled engine (12.95 vs. 15.1 ft-lbs); nothing make torque like cubic inches. Given the YT videos, I've seen, showing the 125 cc Honda mini's on dirt, it seems like 10 - 15 hp is sufficient for exploring off-road (KPM offerings notwithstanding). Is it true (I saw on some YT video) that Lifan is/was making some engines for Honda? I suspect that this will make a Great world-engine design which Lifan can deploy in sport, cafe and dual-sport bikes. I suspect that Lifan will see widespread (world-wide) demand for this strong 200 cc engine? The cafe and sport bikes, using this new engine, on the Lifan world site are spec'd at 152 kg (152 kg * 2.2 lbs/kg = ~333 pounds). 333 pounds seems to be nearly as light as manufacturers can make a liquid-cooled bike; the Kawasaki KLX300, liquid-cooled is said to weigh ~302 pounds (wet); the Honda CRF300L, also liquid-cooled is 306 pounds (wet); the CRF300Rally with a bigger tank, more fairings and a wind-screen is right up around 333 pounds, too. 333 pounds might be liftable and 'flickable' off paved roads? Last edited by Discoveror; 02-03-2023 at 03:12 PM.
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