NGH 60 Inline Twin 4 stroke Petrol Engine
I’ve been testing one of these new offerings from NGH on my test stand in anticipation of using it to displace the DLE 55 currently occupying the nose of my ESM P40. No issues with the DLE it continues to give sterling service but the sound of the 4 stroke twin holds an irresistible attraction!In any case, being a new kid on the block, I though my experience and observations might be of assistance and/or interest to those of you considering this engine. At this stage it’s had about 2 hrs running on the test stand. I’m running 91 octane gasoline mixed with a good quality semi-synthetic air cooled 2 stroke oil mixed at 25:1. The prop is a 2 blade AeroStar 22x10.
General Appearance: The motor appears well made and the finish is comparable with any quality engine on the market. NGH seem to be using the 30cc single head and cylinder as the basis for the twin although I suspect that the twin has a lower compression ratio as the compression is noticeably lower than that of the 30cc single that I have. This has the advantage that a starter will readily fire the twin up whereas it can struggle to spin the 30cc single!
Starting: The engine needs some throttle and choke from cold. It needs to warm up so the choke should be gradually released until it will hold the throttle setting then the engine warmed up. Once warm up is achieved, it should settle to a reliable idle. If the engine has been stopped for 2 minutes or more it needs choke to start, cooling must be very efficient!
Lo Needle Setting: I adjust the lo needle so that the engine will accelerate from idle to full throttle over 1 to 1.5 seconds without hesitation. This way the mixture doesn’t need to be set overly rich to get a transition. (I also use a servo slow on throttle up on 4 stroke glow engines to achieve the same result) The engine has a good reliable idle at 1800 rpm plus or minus.
Hi Needle Setting: Start with it burbling a bit rich at full speed then gradually lean it until the burble just disappears, don’t worry if it gives a couple as it settles at full speed before running cleanly. It should be showing 6000rpm on the tacho at full throttle. I found that the Hi needle was very sensitive, so keep the adjustments minute!
Observations: Throwing an infrared thermometer over the engine didn’t reveal any significant temperature differences between the front and rear cylinders, on the test stand anyway. The engine can be hand started, note the comments above about choke and throttle settings. Vibration levels are less than an equivalent single two stroke especially at low speed. The motor needs some running to bed in and this improves all aspects of its operation.I’ve put a bit of video on YouTube for those interested. Search “NGH 60 in-line Twin” and it should come up on top.
Cheers,
Steve B.