NGH 38CC 4 stroke
10-10-2013, 07:31 AM
#326
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It could be a timing issue....if the spark plug is firing to early, you would see excessive vibrations....especially when at idle...
retarding the ignition could smooth it out some....I would be looking more towards the "inconsistencies in metallurgy" as a culprit.
One thing that you could try is adding more crank weight.... what I mean by that is have 1-blade heavier than the other on the prop..
Place the heavy end of prop inline with the crank end...so when the piston is at or near TDC, have the prop on the verge of upswing or near.... ect....
I Have a ZDZ40f3a that vibrates like crazy... because they removed MUCH of the weight on the crank in attempt to lighten the engine...
It needs a soft/ Hyde type mount to cancel the vibes.… I have not tried the heavy end prop thing and will today... to see if it actually works...
The other option: add 2-more head gaskets! This may lower pressure enough to reduce the vibes some....
The plastic/fiber mounts ads to vibration...or so I am told....
I wanted to pick up the OS 40cc 4-stroke. I am interested in how that runs (in person) but by the looks of it, is a smooth performer....
I know the feeling about the excess vibrations... you wonder "Will this engine TEAR my plane apart?"
retarding the ignition could smooth it out some....I would be looking more towards the "inconsistencies in metallurgy" as a culprit.
One thing that you could try is adding more crank weight.... what I mean by that is have 1-blade heavier than the other on the prop..
Place the heavy end of prop inline with the crank end...so when the piston is at or near TDC, have the prop on the verge of upswing or near.... ect....
I Have a ZDZ40f3a that vibrates like crazy... because they removed MUCH of the weight on the crank in attempt to lighten the engine...
It needs a soft/ Hyde type mount to cancel the vibes.… I have not tried the heavy end prop thing and will today... to see if it actually works...
The other option: add 2-more head gaskets! This may lower pressure enough to reduce the vibes some....
The plastic/fiber mounts ads to vibration...or so I am told....
I wanted to pick up the OS 40cc 4-stroke. I am interested in how that runs (in person) but by the looks of it, is a smooth performer....
I know the feeling about the excess vibrations... you wonder "Will this engine TEAR my plane apart?"
10-10-2013, 07:37 AM
#327
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If it's a "little underpowered" when there is snow on the ground, it will be a complete dog when it's above 85°.
The engine will be making significantly less power & the air will be less dense . Less power+less lift = a stall waiting to happen.
DA is everything, just ask a full size aircraft pilot.
The engine will be making significantly less power & the air will be less dense . Less power+less lift = a stall waiting to happen.
DA is everything, just ask a full size aircraft pilot.
Could be that you end up with more ring "blow by" when hot, and cooler temps will let you richen up the fuel and the cyl will be tighter do the cooler temps....
Engines, from what I am told "racing motocross bikes" make most power in cooler weather...
11-08-2013, 04:46 PM
#328
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NGH 4 Stroke 38CC engine is great build. I bought one here. http://www.aliexpress.com/item/NGH-3...429779801.html
11-08-2013, 07:18 PM
#329
Hobby King has started selling the NGH 38cc four stroke engine now. So it will undercut the dealers more now too, as they are selling at a lower price than the dealers can.
HK is selling the 35cc engine as well.
HK is selling the 35cc engine as well.
11-09-2013, 11:15 AM
#331
I have a new one now from himodel. the latest model is back with 2 piston rings. I have run 2 liter through it and it runs as good as the other i have.
I`m going to put it in a ESM aichi d3a1 val.
I`m going to put it in a ESM aichi d3a1 val.
11-26-2013, 08:40 AM
#334
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I just order one of these from arm-rc.com great price$300.00 and free shipping It should be here in DE USA 11/29/13 Does any know it you can use av gas in this engine. I have 30cc Yak with a DLE 30cc and I have been using reg gas but I thing the ethanol in it and I have had to replace the carb three time in two years I tried to rebuild the carb but could not get them to work, guess I am stock with replacing the carb. I don't want to need to half to replace the carb on the NGH 30cc 4 stoker every six mouths.
11-29-2013, 09:51 AM
#336
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Thanks for the Info, I looked at HK and could not fine any parts on there site. I order the engine from arm-rc.com, they have free shipping and parts in stock, you should check out HKs shipping cost on this engine, WOW that hurts
12-01-2013, 06:54 AM
#341
It was some vibration when I startet it for the first time. It gets better when i got some liters of gas trough it. I also adjusted the timing from 40degrees to 30degrees. loose 200-300 rpm on top, but run better on low rpm. I use a 20x8 prop on the storch. On the aichi d3a1 i am going to use a 18x12.
http://youtu.be/gBCLrpipVyA
http://youtu.be/gBCLrpipVyA
12-01-2013, 12:38 PM
#343
The engine runs realy great. Have startet to run the new one on a stand and it runs great to 
It may not be the most powerfull engine but i have never had a deadstick with it.
I got 5900rpm with a HK carbon 20x8 and 7000rpm with a bambula 18x8
It may not be the most powerfull engine but i have never had a deadstick with it. I got 5900rpm with a HK carbon 20x8 and 7000rpm with a bambula 18x8
12-01-2013, 03:32 PM
#344
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I hope to have mine in on Monday I am going to install it in a Pitts 30cc size biplane 
If you have any tips on start up and any thing on adjusting carb please send . Thank You
12-01-2013, 04:36 PM
#345
The stand offs are fine, as long as you file off a small portion of the one that cant get past the mounting bolt. I took enough off of one post and have not had any problems. The few areas of worry for me is that the soft mounting plate broke in 3 places on my motor. The vibs are so bad it shook the mounting plate untill it failed. And I have tried to get another exahust pipe for mine from the place I bought it (AMR ) and they do not carry the part. That is not to say anything bad about AMR. They have been great to deal with and I will send a few more orders their way for Xmas. As to is it better to use the stand offs or the rail mounts? I guess if I had the area in my plane that could handle the stress, I would go with the rail mount. But as I said before, I have had no probliems with the off sets.
12-01-2013, 06:03 PM
#346
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WOW I had emailed AMR before I ordered my NGH 38cc and they told me they have parts for that engine. I am going to call Dany from AMR on Monday about the parts This is the number I used to call 450-670-2444. I will post what he tells me about getting parts. I pland to use rubber mounts on the stand offs to the fire wall, I hope they will help with any vibs.
12-02-2013, 04:12 PM
#347
Yes, I too sent an E-mail about the pipe. The answer was that the parts were in stock for the motor. But when I called (two weeks ago) I was told they do not carry extra pipes. But that he would look to see if they had an extra that he could send my way. I left him my number, but as of yet have not received the call. I had attached an extention to the pipe and it got so hot the added weight bent the pipe so that it is almost flat at the elbow. This is not AMRs fault and I was not asking for a free pipe. But if you are told they have them in stock, I will call again and order one. Thanks
12-03-2013, 04:23 AM
#348
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12-03-2013, 05:15 AM
#349
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Do you know any thing about removing the back plate and add oil to bearings, this is what the manual said to do. After 10 minutes of break in de-mount the rear crankcase cover and lubricate the bearings.
8. Continue the break in and repeat step 7 after 30min.
Did your manual tell you to do this?
8. Continue the break in and repeat step 7 after 30min.
Did your manual tell you to do this?
12-03-2013, 07:46 AM
#350
both off mine engines was test run att the factory. so i dont had to adjust it to start it. it smelled gasoline from the package before I opened it.
My manual did not say anything about adding oil to the bearings.
I used 4% oil for the break in and is using 2% now.
It spits oil out of the niple under the crankcase so I guess it gets enough oil. it runs much smoother with only 2% oil.
My manual did not say anything about adding oil to the bearings.
I used 4% oil for the break in and is using 2% now.
It spits oil out of the niple under the crankcase so I guess it gets enough oil. it runs much smoother with only 2% oil.
Last edited by tyor; 12-03-2013 at 07:48 AM.