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NGH 38CC 4 stroke

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Old 12-07-2012, 12:48 PM
  #51
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Default RE: NGH 38CC 4 stroke

That is interesting. I would look for a cap head bolt or a large Philips head screw to replace that screw for the carb. Then the standoff would fit.
I guess they had a "oops" with that one.
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Old 12-07-2012, 12:58 PM
  #52
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Default RE: NGH 38CC 4 stroke

I have removed som of the material of the standoff itself.
Still lots of metal left for enough strength.

It would have been nice if thay had tried to install it at the factory before sending the product out.
But its not that big a deal anyway, ill survive

Im going to beam mount it in my P-51 eventualy.
Just wanted to install the standoff to run in the engine on my engine test airfeame.
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Old 12-07-2012, 09:46 PM
  #53
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Default RE: NGH 38CC 4 stroke

I just recieved my engine today.
It looks to be of decent quality, excellent compression too. The only problem is trying to get it started!
It doesn't want to run as good as it looks, and it needs a real muffler very bad. The carb won't pump fuel well enough to keep it running very good.
It sounds like it's laboring when it's running. It doesnt seem to be getting too hot at all when running.
Fuel ratio 25-1, premium fuel.
18-10 Mejlik.
Seems to need chokeing every time to start it, even hot.
I am going to check cam timing, ignition timing, & valve clearance.
Mine does not sound like the ones in the you tube videos.

So far, I'm a little disapointed in the way it runs. Can't put it on a plane like this, going to work with it though and get it figured out!

Mark
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Old 12-08-2012, 06:58 PM
  #54
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Default RE: NGH 38CC 4 stroke

I checked the timing, and it was at about 42 deg. BTDC, which seems too far advanced. So I retarded the timing about 10 deg. to help the kickback issues during starting. That helped a bunch for starting this thing up. I ran it for about 45 mins. to an hour straight and it got better at running. Then I noticed the carb dripping fuel quite a bit while running at idle, need to check into this problem further. Went to check the valve clearance and noticed the rocker arms are VERY SLOPPY on the pivot shafts, almost like they didn't even try to get the right size ream for the proper fit. Iv'e had alot of four strokes in my past, the most currant a Saito FG-57T, and NONE of them had ANY kind of slop like this.
I gotta say, this engine has alot of great potential, because when it's running, it makes some pretty good power!
Now for the carb issue....
By the way, does anyone know what the timing should be with the degree wheel?


Mark.
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Old 12-08-2012, 07:43 PM
  #55
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Default RE: NGH 38CC 4 stroke

This has to be the smoothest running gasser I ve ever heard.
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Old 12-09-2012, 10:28 AM
  #56
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Default RE: NGH 38CC 4 stroke

Hi Mark
Thanks for the updates.

I would say the timing should be at 28 degrees before TDC....just like the 2 stroke engines ?

I used this simple method to time my 2 stroke 50cc, and it runs great :
http://www.phprc.net/images/engine-timing.pdf


Havn`t measured it on the GF-38 yet.
My pickup is exactly at the 3 o`clock position when the engine is viewed from the front.
Was your there too when you got the engine ?
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Old 12-09-2012, 10:43 AM
  #57
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Default RE: NGH 38CC 4 stroke

I just measured mine, and out of the box it is at 33.5 degrees.
I would say that is a bit much.
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Old 12-09-2012, 11:59 AM
  #58
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Default RE: NGH 38CC 4 stroke

sorry...I measured wrong...it it 43 degrees BTDC out of the box.
How can this be right ?
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Old 12-09-2012, 01:12 PM
  #59
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Default RE: NGH 38CC 4 stroke


Quote:
ORIGINAL: MKnutson

I just recieved my engine today.
It looks to be of decent quality, excellent compression too. The only problem is trying to get it started!
It doesn't want to run as good as it looks, and it needs a real muffler very bad. The carb won't pump fuel well enough to keep it running very good.
It sounds like it's laboring when it's running. It doesnt seem to be getting too hot at all when running.
Fuel ratio 25-1, premium fuel.
18-10 Mejlik.
Seems to need chokeing every time to start it, even hot.
I am going to check cam timing, ignition timing, & valve clearance.
Mine does not sound like the ones in the you tube videos.

So far, I'm a little disapointed in the way it runs. Can't put it on a plane like this, going to work with it though and get it figured out!

Mark


I will say I got the NGH 35Rear Exsaust. And I have always had issues with it hand starting. I just gave up, put a 4s lipo on my electric starter and Use the electric starter with the choke on and thro on mid unitll it burps. Then take the choke off and hit it with the starter and with in 2 sec its running. IT is actully faster to start with the starter than hand start my dle motor for the first time.

Good Luck Mike
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Old 12-09-2012, 03:28 PM
  #60
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Default RE: NGH 38CC 4 stroke

Sorry guys,
This engine is a huge waste of time and money. There are other engines out there in this size class that we KNOW work well for less money.
I just thought that it would be cool to try a large 4-stroke gas single, other than Saito.
NGH has a little work to do before I trust their engine on any of my planes.
Today I worked on it for about 6 hours, tweaking, installing new carb diaphrams, different fuel, diff. props, diff. plugs, batteries, etc...to no avail.

I'll call it a lesson learned, and $400 lighter in the wallet.

Maybe I got a bad one, who knows, just beware.

Mark.
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Old 12-09-2012, 04:02 PM
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Default RE: NGH 38CC 4 stroke

SJN,
My engine's timing was at 42 deg. out of the box, and it liked to kick back during hand flipping and would fire and kill itself.
It's too bad this didn't work out, next time I'll just wait and see how things go with other people and products before I jump in.

Mark
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Old 12-09-2012, 04:27 PM
  #62
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Default RE: NGH 38CC 4 stroke


Quote:
ORIGINAL: MKnutson

SJN,
My engine's timing was at 42 deg. out of the box, and it liked to kick back during hand flipping and would fire and kill itself.
It's too bad this didn't work out, next time I'll just wait and see how things go with other people and products before I jump in.

Mark
Mine works fine.

Best regards
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Old 12-09-2012, 05:11 PM
  #63
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Default RE: NGH 38CC 4 stroke

Well NGH did have the static timing for the little NGH 9cc engine set pretty high too.  I was thinking it had to do with the CDI unit they got from RCexl for their engines. The microprocessor inside may be a little slow in getting the timing signal and responding to it. So there is extra time delay needed for the timing to work out right. So this may be quite normal for those particular CDI units they are using.


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Old 12-09-2012, 05:20 PM
  #64
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Default RE: NGH 38CC 4 stroke

Well....I guess I don't know what to think now. I have been running Nitro for the past few years, and the gassers I did have were well behaved 2 strokes. Time shall tell, and I don't know that much about gas four strokes, so doing all those adjustments is beyond me. I hope it runs well. Is the plug going to have to be replaced as some gas motors do to stop radio noise?
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Old 12-09-2012, 05:30 PM
  #65
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Default RE: NGH 38CC 4 stroke

Yeah it sometimes has me wondering what the hobbyists were talking about, way back in the 1930's, 1940's and 1950's about the spark ignition gas engines they were using. I am sure the tether car and tether boat people would have gotten into all sorts of discussions about the engines of that era.

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Old 12-09-2012, 05:57 PM
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Default RE: NGH 38CC 4 stroke

Quote:
ORIGINAL: earlwb

Well NGH did have the static timing for the little NGH 9cc engine set pretty high too. I was thinking it had to do with the CDI unit they got from RCexl for their engines. The microprocessor inside may be a little slow in getting the timing signal and responding to it. So there is extra time delay needed for the timing to work out right. So this may be quite normal for those particular CDI units they are using.


RCEXL ignitions on NGH engines are standard A01 module.
I think some people does not check the angle properly.
On NGH engines (GT9 included) the manufacturer says the angle is 40 degrees BTDC , BUT measured from the center of the magnet to the center of the sensor housing, and all people knows (?) the RCEXL manufacturer says the angle is 28-30 degrees from the trailing edge of the magnet to the trailing edge of the sensor inside the housing, some degrees less than the other measurement method.
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Old 12-09-2012, 08:18 PM
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Default RE: NGH 38CC 4 stroke

When I measured the timing on my engine I used a degree wheel and the actual spark of the plug to tell me where it was at BTDC.
mpascual, I'm glad yours runs good, I really wanted this thing to work because my old 30cc Yak 54 could use it.
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Old 12-09-2012, 09:03 PM
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Default RE: NGH 38CC 4 stroke

Is it possible that the engine cam timing is off by one tooth and cause this problem??? Just saying. Capt,n
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Old 12-09-2012, 09:20 PM
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Default RE: NGH 38CC 4 stroke

Mr. SJN and all bought NGH38 people:

I am so sorry for the standoff installation problem. It is a stupid mistake, each NGH38 must be tested before shipping. but standoff parts are separated packing, workers packed a big-head M5*40 screws and wrong. I had not paid enough attentions while I am moving factory from North to South China. 

It is a really stupid work and shame, please forgive my mistake.

Now, please try to use these method to install it.

a. if possible, better is with beam mounting.

b. try to find  small-head M5*40 screws.

NGH will never escape and make solutions.

Sorry again

michael


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Old 12-09-2012, 10:49 PM
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Default RE: NGH 38CC 4 stroke

"Will never escape and make solutions"? I think that's an apology of sorts... I think. It's O.K. Michaelchow, your English is a hell of a lot better than my Mandarin.
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Old 12-10-2012, 12:26 AM
  #71
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Default RE: NGH 38CC 4 stroke

Hi Michael.

Sometimes these things happen
The standoff problem is not a big problem.

Can you tell me how many degrees of ignition timing you used on the prototype engine you have running ?


In these pictures the piston is at TCD
and the timing is at 43 degrees BTDC
I made a timing mark on the prop hub, and case.
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Old 12-10-2012, 01:05 AM
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Default RE: NGH 38CC 4 stroke

Mr. Johannesen,design for this is 40 degrees, +-3 degrees are ok with any adjustment 
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Old 12-10-2012, 01:16 AM
  #73
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Default RE: NGH 38CC 4 stroke

other features:
a. double piston-rings: NGH38 still use a high precision sleeve and two piston rings, make the engine with good compression but more friction reduce RPM.
b. lubricating: two pipelines connection with rear cover and intake manifold, one connection is for pulse from crankcase to carburetor, and one connection is for transferring oil mixture from carburetor return to crankcase for lubricating.
c. carburetor matching: custom WT1022, always testers test it with 1.5 turns from full close for LSN and HSN.
d. prop size: 18*8-20*8, 20*8 always get 6kg tension, but smaller prop might get 7kg.


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Old 12-10-2012, 09:25 AM
  #74
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Default RE: NGH 38CC 4 stroke

ocumentProperties>00122131Vulcan hobbies1115214.0ocumentProperties> Normal0falsefalsefalseoNotPromoteQF />EN-USJAontGrowAutofit />ontFlipMirrorIndents />

Hi>>

Just got mine in the post, looking forward to putting it my mustang it looks a fine engine>>

Also a good delivery service from www.vucanhobbies.co.uk

I will keep you updated on the running of it.
>>

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Old 12-10-2012, 10:13 PM
  #75
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Default RE: NGH 38CC 4 stroke

Hi all,
I put the timing back to stock, 40ish degrees, and installed a 20-8 wood prop. I got it started after alot of choke and let it run at a fast idle for about 30-45 min.
The guy I got the engine from wanted me to run at least a full gallon through it before passing judgement on it. The eng. did seem to like the 20-8 wood better than the heavier carbon props I was trying earlier. After running for a bit, the carb did stop leaking. I'm going to just run the bujesus out of it on the stand to get it loosend up more. It didn't seem to run any different with the higher timing so I'll just leave it there. I do wish they would offer a muffler for it though.
By the way, where do we get parts if needed?

Mark.
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