av8tor1977

My Feedback: (6)

OS = Great Engines but way too much money.

AV8TOR

dirtybird

My Feedback: (5)

I have an NGH26. Its a great engine. But both the 17 and mine do not have roller bearings on the rod lower end. So you are stuck with a 30/1 mixture with 20/1 better.
I also have an RCGF 17. It has roller bearings on the rod lower end. Unfortunately mine failed the first time I tried to run it. The MFG replaced the engine.

BTW the NGH engines use a 1/4x32 plug. It costs at least $12 if you get it from China.

hsukaria

I don't have experience with the smaller 1/4x32 spark plugs, do they fail more often than the CM6 plugs?

I use 32:1 fuel on my other gassers, would that work for the NGH engines?

dirtybird

My Feedback: (5)

The 1/4x32 plugs are more delicate and they cost 3x the CM6.
I would think 32/1 would be OK.But it would be safer to go to 30/1 on the other engines.

hsukaria

I don't mind going to 30:1.

Sundance2018

Hi Guys -
Thanks for all of your input...it's been most helpful
Personally, I am okay to spend a bit more $$ to get something extremely high quality / high reliability. I have zero experience with Evolution engines, but have read a lot of good reviews about them. What say you guys about that?
Regarding OS engines, now those I have quite a bit of experience with but only glow AND my experience has been a hit or miss. I've been running and OS 60 in Goldberg Protege' and it's been terrible (I have always figured though that I must be doing something wrong with it). I wish ENYA made small gassers!
And I have some experience with Saito's but again not with any gas variety.
I have never heard of NVH engines, but have been very skeptical of a lot of the stuff coming out of China and Japan these days.

Anyway, the OS 10cc is supposed to run on a 50:1 mix which would tell me that the engine must be made very well and that it is also burning fuel very cleanly. Am I correct in this assumption? My project that I want this for is a Great Planes Ultimate 40 Biplane. I've seen these fly nicely on everything from a OS 46 up to a Saito 82.
Looking for ideas, guys, so please keep the comments coming

av8tor1977

My Feedback: (6)

Personally, I'm still just not sold on any gasoline engine in the sizes below 20cc. I would rather have a Walbro carb with its easy to source parts and well known reliability than the proprietary carbs coming out on these newer small engines. For me, it is glow below 20cc, and gasoline above; but that is just my opinion. If glow fuel costs you too much running an engine below 20cc, then just raise the compression a bit if necessary, and run methanol from a speed shop or go kart racing supply, along with the appropriate amount of oil.

Having said that, I do have a Super Tiger .90 running on gasoline. But it is a BME model converted with roller bearings and a Walbro carb, and I do fly it a lot. But it is an expensive engine, and as far as I am concerned, an exception to my "rule".

Note that if you want to, you can still run a glow fuel engine on spark ignition if you want the extra reliability that provides. But then I have never had problems with glow engines quitting on me unexpectedly, so that idea is in question too, as is the extra weight the electronic ignition entails on these size model airplanes.

AV8TOR

dirtybird

My Feedback: (5)

https://www.rcgfusa.com/rcgf-10cc-3

hsukaria

At these engine sizes, is it better to go with the rear intake with reed valves, or front intake with the ported crankshaft? It would seem that avoiding the reed valves would be a plus, IMHO.

But it is a cute looking engine. It is also capable of running at 32:1 fuel/oil mix. That is pretty good for that small size.

fujiman

My Feedback: (133)

which walbro (#) is on your .90 ST?

captinjohn

E85 works real good in some of the real big SuperTiger engines. I seen it & know it works. Not just heard it.......

hsukaria

Hi captinjohn, would you know what oil ratio and glowplug to use with E85 with the big ST's?

av8tor1977

My Feedback: (6)

When converting a glow engine to gasoline, unless you convert the rod and crank pin to roller bearings, use the same oil ratio/percentage that you would with glow fuel, if not more. An engine uses much less gasoline than it does methanol, (glow fuel), so there is an argument that even more oil might be a good idea. That's one of the pitfalls and problems with converting a glow engine to gasoline, besides the fact that gasoline makes an engine run hotter, and the cooling fins on a glow engine are designed for the cooler running methanol.

As far as a carb for the Super Tiger .90, 11mm would be the max size venturi to use, with slightly smaller sizes being more user friendly as far as needle settings and throttle up transition. There is barely enough room to mount a Walbro carb. I had to do some grinding on both the engine and the carb to get mine to fit. Zama carbs are just a bit smaller externally, and fit the application better.

AV8TOR

prigai

I use a 9.5mm Venturi Zama carb on the ST G90, still bushing conrod 15:1 petroil and works well.
I wouldn't go above 9.5mm (size 24 = 24/64"), the 11mm (28) works but transition and handling suffer.

captinjohn

I have the persons phone number that ran the big SuperTiger. If the phone number is still good, I will call & find out more. I think the ratio was less than standard Glow fuel. Best Regards, Capt,n

Jersy Hank

BOY O BOY Did any of you guys ever run an OLSEN & RICE 23 or 60 ? We had to use WHITE gas & 50 wt. Ave. oil in them. Also trops bantam brunch & the best of the lot a G.H.Q add to that list Mecoy Foster 99 & Afew MEGO O so many flying with battery coil points & condenser. Do not beef about today you have it easy!!

drac1

My Feedback: (4)

I run 10% oil in my ST 4500 on glow.

drac1

My Feedback: (4)

1. I always mix own fuel. I buy the methanol from a service station that races speedway and mix appropriate Coolpower oil %. Runs just as well as pre mixed fuel, but much cheaper.

2. I've never had problems with glow engines quitting either, so the ignition reliability is not an advantage. What is an advantage for ignition over glow on methanol engines, is the idle can be set slower, has more mid range torque so can turn a larger prop and will use about half the amount of fuel as a glow set up.

dirtybird

My Feedback: (5)

Actually gasoline has more lubricity than alcohol. Alcohol has none. So you can use less oil in the mixture.
My NGH26 does not have roller bearings on the rod. It is happy with a 30/1 mixture.
A glow engine should be happy with 20/1 if it has enough fins. The large amount of alcohol required has a better cooling effect than gasoline.

av8tor1977

My Feedback: (6)

That's true about the lubricity of gas versus alcohol, but I still think a lot of these guys running low oil ratios in engines converted from glow to gas are one slightly lean run away from a trashed engine.

AV8TOR

dirtybird

My Feedback: (5)

I ran gas engines for 10 years before the glow plug came about. My favorite engines were the Orwik 64 and the Anderson Spitfire 65. As I recall we used 70 wt oil with a 4/1 mixture.
Todays oil is a bit better than that old 70wt
I dont know if anyone got a GHQ to run. If I remember correctly it was supposed to run clockwise instead of ccw.

captinjohn

30-1 ratio burning gas does not seem to good at all with a non roller bearing engine. Just like AV8TOR says. PS, do not her too hard on a hot day ! Capt,n

Jersy Hank

Glad to see some one else who has made a trip around the block a time or two. They were some great engines back the. Any one know when the first gasser was used at the NATS & where?

Sundance2018

Hi Guys -
After a LOT of careful consideration, I decided to buy the OS GGT 10cc. I know it was a bit more pricy that some of the other engines you guys have talked about, but I have always had good success with OS engines. I think the main deciding factors for me was the idea of the glow ignition as well as the very low (50:1) gas/oil mix. As I mentioned in a previous post, my project is the Great Planes Ultimate 40 biplane. With that said, I really worried about the extra weight of and where to fit the ignition module. It was a tough choice between the OS GGT or the Saito FG11, but through Tower I was able to get the OS for $280 w/ their summer sale and so was able to save a few $$. The reviews on it seem very positive as well.
Anyway...just thought I would share and hoping I made a good decision. Still gotta build the plane so we'll see how it all ends up I guess.
Tom

Jersy Hank

Well wish you good luck. I have not run any gasers since O/R & Brown Jrs. Personally I would use an Electric set up. Just saying.