bmarks,

What plug do you use now?

Barry,


The right plug range for this engine is medium heat. The OS A3 is too hot and you need to adjust the engine significantly richer to avert detonation (what a lean-run really is).

This would make the OS #8, Enya #4, Rossi R4, Novarossi/MVVS C6-S, K&B-1L, the newer Tower and other plugs suitable.


The OS #8 has been changed lately and not for the better... Sigrun mentioned this in two recent threads.
He says they are only like the older OS #8 in their appearance, but are lousy from every other aspect...

Hanger 9 3001.

This is the plug that came with engine.

Brian

Dar,

As you well know, there are many variables in running a model airplane engine. That's why the engines have needle valves and there are many different glow plug, fuel, and prop manufacturers.

Before anyone makes any quotations, it would be best for them to take these many variables into consideration.

You were not standing beside the engine with BLW and me the day that the OS #3 recomendation was given. If you were, then I'm sure you would have had the same recomendation as I did. Especially if that was the alternative you had in your flight box. Also considering that the engine then ran well with no pinging and it also ran well again yesterday when the temperature was 86 degrees...

There may be a time in BLW's future that he has to use a different plug than the #3? But the #8 was far too cold for his engine that day.

Enjoy,

Jim

Jim,


I give some of my recommendations, from engine type and construction.

This specific engine is made (as I was told) by Sanye, like Magnum, ASP and SC engines and has the same general construction.
It was also tested by the leading R/C magazines and found to be similar in power to the OS FX and to similar engines.

I don't think this engine should differ from them by any large degree, in its ignition needs and by the book, it would seem the OS #8 and other medium heat plugs should be suitable for it.

It could be, however, that in the interest of easier operation, the manufacturer changed to a lower compression ratio.
This would require a hotter glow-plug.
The situation would be so, if the engine cannot be leaned down enough, so as not to lose much RPM when the glow driver is removed.
If an unreasonable RPM loss is persistent with a new plug, known to be good, a hotter grade plug is needed.

The 10-30% nitro recommendation (more than OS and other Sanye engines) seems to be coherent with this assumption.

The only recommended plug is the H9 Super Plug, which does not feature a heat range... See photo.


The setting of the needle valves is the last variable...

It is adjusted after the manufacturer determined the suitable load (prop size), nitro percentage and set the compression ratio.
This is the last thing that is adjusted, so the engine would run at its best, with the given constants.

The fact that with plug 'X' an engine CAN be adjusted to run, without detonating and without losing RPM on removal of the glow-driver, does not make this plug right. It could be the mixture is adjusted richer than ideal, to avert detonation, since the plug is too hot.
The engine would then become too rich in the mid-range...

This problem affects many because everybody is using the cheap A3...

Great info on glow plugs for a novice. My specific problem is the engine not running properly, but when I flip start it the engine runs clockwise more often than counterclockwise. Is this related to heat range of plug?

Thanks,

Brian

It could be a little too rich?
Best way to cure that is with an electric starter...

FWIW I currently have a "hot" Fireball in mine...inverted in the Cermark Bobcat. Runs fantastic(ly?) in this weather anyway...(mid 60's spring temps, 10% nitro, 10X7 APC )

Mine has had the H9 (looks like a 4 stroke ) plug, an O.S. #8 and type F, a Fox "Miracle" and Fox std. long, and probably a few others...

Best out of those are the H9 plug that came in the engine, and this Fireball...

No, Brian.

This is usually the result of over-priming. Reduce the priming to 1-2 revolutions.


When you want to flip start your engine, first of all, mount the two-blade prop on the shaft so it is level; parallel to the wings, when compression is encountered.

Now, master back-flip bump-starting!

Don't flip the prop counter-clock-wise over compression. In stead, bump it sharply clock-wise, against compression, while 'soft-fingering' the blade's leading edge, so your finger(s) will slip away from the advancing blade.

It will most likely fire, if the prime is right and start in the normal direction.


It works and you are less likely to hurt yourself doing it so.

Thanks,

I'll try these suggestions over weekend.

Brian

Both of my Evolution engines are easy to start. I have run the .45 and .46 a lot. The noticable problem is that once started the crankcases seemed loaded and they wouldn't run smoothly until the throttle was massaged and wide open achieved. This took time.

The .45 is simply a hot engine that puts out a lot of power when the flywheel weight is removed and something along the lines of a 11x7 prop is used. The engine that I have has more than a hundred flights without a deadstick, except for 2 when there was trash in the needle valve. It just wants to run and doesn't care how you run it.

The .46NT replaced an OS .46FX. That replaced a TT Pro .46. I don't recall breaking in the .46NT. I did run it a couple of minutes before putting it on the same plane. I got some comments on my first takeoff run about how much more power the Evo seemed to have over the .46FX. This was with the OS 8 plug and the engine developed more power after a few tanks of fuel.

I'm not a 3D flyer, but there are a lot of Somethin Extras at my club and those guys do hover. The .46NT is on a SE and being that I once flew helicopters I sometimes feel like I should at least give it a try for grins. Before changing from the OS 8 to the Towers plug I could sustain hover power at 75% throttle. It is now less than half throttle with the Towers plug. That is all that changed. Same Omega 15% fuel, same APC 12.25x3.75 prop. I could not take off and pull vertical and accelerate with the #8 but I can now. Well, I did put a Towers muffler on the engine and not on the OS or TT. The Towers plug made much more difference in performance. Yes, I did have to tune the HS needle valve, but I hadn't flown the engine since cold weather and can't comment more on that.

I keep forgetting to drag out the RCMs with the .45 and .46 teardown and review. I think both were by Clarence Lee. I don't recall any comments about lower compressions but I will find them and see. I've searched a couple of other places and compression isn't mentioned. I would be surprised if this were true. These engines are well made, well designed, and a great bargain considering they are chromed. They are not cheap knockoffs.

The .46NT was tested by Clarence Lee in RCM magazine and he said that compression is 7.7:1.

CL references his compressions from where the exhaust port closes. The geometric compression is more likely to be around 10:1 which is pretty much standard for most sport engines. There are arguments either way as to which is more correct but CL seems to be in the minority with his way.

Yes, he does state how he figured it. At least he explains that.

Kinda interesting how you can convert the .40 Alpha to either a .45 or .46.

How does the Evo .46 run on an Ultra Stick? I'm considering this plane for my second plane and I am trying to find a good engine. I am considering this one, the O.S. .46AX, the Thunder Tiger Pro .46, and the Megatech .46 (I already own a Megatech .46, and it's not bad at all for the price). So my question, is the Evo a suitable choice, or should I go with one of the others?

Mount the engine on its side and enjoy

Why do you need to mount it on its side?

Ronnie,

...So the center-line of the fuel-tank, which is inside the fuselage, directly behind the engine's crankshaft, would be at the same level as the carburettor's spray-bar, so the engine will behave the same in level and inverted flight and also, will not have its fuel flow affected very much by high G maneuvers.

It will only be a little richer, or a little leaner in knife-edge; depending on the side you choose to cut...

I see. Thanks! I actually found the answer to my question when I was reading another thread on here. I am fairly new to RC planes, and don't know a whole lot about engines yet, other than how to make it run right and not dead stick (and I'm not that good at doing that). But I'm learning fast thanks to RCU.

Ronnie,


I would guess I wrote that post too...

Cheers,

I have the Evo 46 on a Hanger 9 Twist and really like it. Is there a tuned pipe that will fit this engine out there?

Thanks,
Bob

Either the Jett Engineering or Performance Specialties Ultra Thrust tuned mufflers will work. They should add 1,000 rpm or so to most props.

Does the Evo, like all other OS clones from Sanye China, have the same exhaust port configuration and bolt spacing?

If the answer is positive, any OS FX muffler and aftermarket exhaust will fit.

Yep...the Tower muffler fits like a glove...same with the Macs "Pre-Tuned" pipe set-up for the O.S. .46FX / TT .46 Pro...

yes. I've had a .46FX muffler on mine to see. The Tower muffler is a direct fit even though the .46NT is not a clone of anything else. If a tuned pipe will fit a .46FX then it should fit the .46NT.

I have crashed 2 planes with the same Evolution .46 engine, one crash was at full speed nose first. The engine still runs great. I am going to remove the flywheel now and get a tuned pipe and bolt it up to a Lancair 360. I hope that it continues to work good. Has anyone tried this engine on a Lancair 360?