NGH 38CC 4 stroke
11-19-2012, 12:32 PM
#26
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RE: NGH 38CC 4 stroke
It looks like these guys have it http://www.amr-rc.com/index.php?path...1821&langue=en
11-19-2012, 01:05 PM
#27
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RE: NGH 38CC 4 stroke
Some pictures of engine:
Exhaust valve guide. It seems bronze. Picture taken with a USB microscope through exhaust mainfold. Well lubricated !!!!
The connecting rod with needle bearings on both sides, and centered on the piston pin with two spacers.
Exhaust valve guide. It seems bronze. Picture taken with a USB microscope through exhaust mainfold. Well lubricated !!!!
The connecting rod with needle bearings on both sides, and centered on the piston pin with two spacers.
11-26-2012, 11:06 AM
#29
Thread Starter
RE: NGH 38CC 4 stroke
Well, I just ordered one from Norway 
http://www.throttlestore.com/engines...e.aspx?lang=EN
As it has to go through customs, i expect it to take some time before I will get it in my hands...
At least there are a few more videos out now.
"Xoar 19x8 prop
Idles smooth at 17-1800 rpm and full throttle with these propellers at max 6230RPM"
http://www.youtube.com/watch?v=jgsMz...eature=related
and this one:
http://www.youtube.com/watch?v=gfiSpIg8pz0
http://www.throttlestore.com/engines...e.aspx?lang=EN
As it has to go through customs, i expect it to take some time before I will get it in my hands...
At least there are a few more videos out now.
"Xoar 19x8 prop
Idles smooth at 17-1800 rpm and full throttle with these propellers at max 6230RPM"
http://www.youtube.com/watch?v=jgsMz...eature=related
and this one:
http://www.youtube.com/watch?v=gfiSpIg8pz0
12-03-2012, 04:59 PM
#32
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RE: NGH 38CC 4 stroke
ORIGINAL: captinjohn
Thanks for the photos. The rod & all the inside,s look very well built. Capt.n
Thanks for the photos. The rod & all the inside,s look very well built. Capt.n
I really think NGH is improving the quality of their creations.
The only thing i don't like is the 90 degrees spark plug cap. I've replaced it by a 120 degrees CM6 spark plug cap and boot similar to mounted on new DLE35RA ignitions. Much better fit.
Now i'm searching a nice airframe to mount this little jewel on front and see how it performs in the air.
Best regards, captinjohn
12-03-2012, 08:48 PM
#33
RE: NGH 38CC 4 stroke
mpascual, that is a better anglefor the sparkplug lead with the 120 degree angle. I see 2 lines from crankcase too intake manifold? Just curious to what does what ! Thanks Capt,n
12-04-2012, 09:44 AM
#36
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RE: NGH 38CC 4 stroke
I always verify/adjust the timing with a timinig wheel. In this case was OK from factory.
I will try with different ignition 'curves' but i suspect (as with many others engines) , the standard A01-A2 retarding curve from RCEXL is the best compromise.
Best regards
I will try with different ignition 'curves' but i suspect (as with many others engines) , the standard A01-A2 retarding curve from RCEXL is the best compromise.
Best regards
12-04-2012, 10:24 AM
#37
Thread Starter
RE: NGH 38CC 4 stroke
Opened up my engine to inspect it, and all looks good.
The valve springs seem a little weak, and will probably limit the RPM of this engine......but that is just my guess...
8000 is the max reccomended stated in th emanaul anyway...
The engine is timmed at 6/12 o`clock.
But, the valve clearance is no good from the factory....or the lack of it.
Both my lifters where pressing slightly on the valves, where there should be slack/clearance.
So I took my saito feleer gauge, which I think is at 0.10mm and set the valves to that.
The valve springs seem a little weak, and will probably limit the RPM of this engine......but that is just my guess...
8000 is the max reccomended stated in th emanaul anyway...
The engine is timmed at 6/12 o`clock.
But, the valve clearance is no good from the factory....or the lack of it.
Both my lifters where pressing slightly on the valves, where there should be slack/clearance.
So I took my saito feleer gauge, which I think is at 0.10mm and set the valves to that.
12-05-2012, 02:36 AM
#38
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RE: NGH 38CC 4 stroke
ORIGINAL: SJN
Opened up my engine to inspect it, and all looks good.
The valve springs seem a little weak, and will probably limit the RPM of this engine......but that is just my guess...
8000 is the max reccomended stated in th emanaul anyway...
The engine is timmed at 6/12 o`clock.
But, the valve clearance is no good from the factory....or the lack of it.
Both my lifters where pressing slightly on the valves, where there should be slack/clearance.
So I took my saito feleer gauge, which I think is at 0.10mm and set the valves to that.
Opened up my engine to inspect it, and all looks good.
The valve springs seem a little weak, and will probably limit the RPM of this engine......but that is just my guess...
8000 is the max reccomended stated in th emanaul anyway...
The engine is timmed at 6/12 o`clock.
But, the valve clearance is no good from the factory....or the lack of it.
Both my lifters where pressing slightly on the valves, where there should be slack/clearance.
So I took my saito feleer gauge, which I think is at 0.10mm and set the valves to that.
Be careful with valve clearance.
On engines like this one I always set valve clearance close to zero (no clearance) but avoiding pressing the valves, when engine is cold.
Best regards
12-05-2012, 07:41 AM
#40
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RE: NGH 38CC 4 stroke
ORIGINAL: SJN
Setting the valve clearance to zero seems like a very bad idea to me.
How mch have you run your engine ?
Setting the valve clearance to zero seems like a very bad idea to me.
How mch have you run your engine ?
Check the clearance when engine is very hot and after a full tank, and then let me know the clearance. Then maybe you will change your opinion.
In a gasoline four-stroke cylinder the expansion of cylinder and head is greater than the valve rod pushers. I've learning this lesson servicing Saito gas engines, and always i set clearace close to zero.
Also i've received a tech note from the manufacturer with this recommendation
Best regards
12-05-2012, 07:56 AM
#41
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RE: NGH 38CC 4 stroke
From Saito gas engine user manual (2012 version)
.....
In that position, adjust with the included gauge and
hexagonal wrench so the tappet gap may be set to
almost zero when the engine is in the compression
stroke. If the gauge can enter a limit gauge with a 0.1
mm thickness, the clearance is at maximum and needs
adjustment. Adjust between 0.03 and 0.10mm (0.002
to 0.04 in.) After the gap is checked, tighten the locknut
securely. Do not over-tighten.
The tappet gap is the most important factor in the
maintenance of 4-stroke engines, and operation with
an excess clearance will degrade performance. In
particular, a large gap aggravates abrasion of the tappet
and the cam and also increases the unusual sound.....
Maybe this info is a very bad idea .......
Best regards
.....
In that position, adjust with the included gauge and
hexagonal wrench so the tappet gap may be set to
almost zero when the engine is in the compression
stroke. If the gauge can enter a limit gauge with a 0.1
mm thickness, the clearance is at maximum and needs
adjustment. Adjust between 0.03 and 0.10mm (0.002
to 0.04 in.) After the gap is checked, tighten the locknut
securely. Do not over-tighten.
The tappet gap is the most important factor in the
maintenance of 4-stroke engines, and operation with
an excess clearance will degrade performance. In
particular, a large gap aggravates abrasion of the tappet
and the cam and also increases the unusual sound.....
Maybe this info is a very bad idea .......
Best regards
12-05-2012, 08:12 AM
#42
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RE: NGH 38CC 4 stroke
ORIGINAL: captinjohn
mpascual, that is a better angle for the sparkplug lead with the 120 degree angle. I see 2 lines from crankcase too intake manifold? Just curious to what does what ! Thanks Capt,n
mpascual, that is a better angle for the sparkplug lead with the 120 degree angle. I see 2 lines from crankcase too intake manifold? Just curious to what does what ! Thanks Capt,n
The second one is to release high pressure inside the crankcase when the piston is going down, to the intake mainfold, and also to get oil-petrol from intake for con-rod lubrication when piston is going up.
On this engine the amount of oil passing through the piston ring gap is lower than other engines because it mounts two rings
Best regards
12-05-2012, 09:00 AM
#43
RE: NGH 38CC 4 stroke
Question...why is 2 rings used? Seems like 1 piston ring like a Frank Bowman ring would be fine with less friction. Also that oil needs to be in bottom end for lubrication of the rod bearings.Best Regards,Capt,n
12-05-2012, 09:47 AM
#44
Thread Starter
RE: NGH 38CC 4 stroke
I think you are mis-reading the saito manaul.
It says that the clearance must be within 0.03 and 0.10mm
"
In that position, adjust with the included gauge and
hexagonal wrench so the tappet gap may be set to
almost zero when the engine is in the compression
"
With a gauge in between the valve and tappet the gap may be set to almost zero.
Not without a feeler gauge....
But you are right that 0.10 is probably too much, as it is at the maximum of the reccomended gap.
I will adjust it to 0.03mm
It says that the clearance must be within 0.03 and 0.10mm
"
In that position, adjust with the included gauge and
hexagonal wrench so the tappet gap may be set to
almost zero when the engine is in the compression
"
With a gauge in between the valve and tappet the gap may be set to almost zero.
Not without a feeler gauge....
But you are right that 0.10 is probably too much, as it is at the maximum of the reccomended gap.
I will adjust it to 0.03mm
12-05-2012, 05:08 PM
#45
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RE: NGH 38CC 4 stroke
ORIGINAL: SJN
I think you are mis-reading the saito manaul.
It says that the clearance must be within 0.03 and 0.10mm
''
In that position, adjust with the included gauge and
hexagonal wrench so the tappet gap may be set to
almost zero when the engine is in the compression
''
With a gauge in between the valve and tappet the gap may be set to almost zero.
Not without a feeler gauge....
But you are right that 0.10 is probably too much, as it is at the maximum of the reccomended gap.
I will adjust it to 0.03mm
I think you are mis-reading the saito manaul.
It says that the clearance must be within 0.03 and 0.10mm
''
In that position, adjust with the included gauge and
hexagonal wrench so the tappet gap may be set to
almost zero when the engine is in the compression
''
With a gauge in between the valve and tappet the gap may be set to almost zero.
Not without a feeler gauge....
But you are right that 0.10 is probably too much, as it is at the maximum of the reccomended gap.
I will adjust it to 0.03mm
When i set the clearance on gas engines, like SAITO, and this one NGH i set the clearance to almost zero without the feeler gauge. But i'm sure the valves are fully closed.
I only use the 0.03 feeler gauge from the OS 4S toolkit when i adjust glow engines.
Best regards
12-05-2012, 05:41 PM
#46
RE: NGH 38CC 4 stroke
ORIGINAL: SJN
Setting the valve clearance to zero seems like a very bad idea to me.
How mch have you run your engine ?
Setting the valve clearance to zero seems like a very bad idea to me.
How mch have you run your engine ?
12-07-2012, 09:37 AM
#49
Thread Starter
RE: NGH 38CC 4 stroke
Have you guys tried to install the included stand-off`s ?
3 of them install fine, but the fourth one fouls on the carb bolt, and cant be installed. [&:]
3 of them install fine, but the fourth one fouls on the carb bolt, and cant be installed. [&:]
