GallopingGhostler

Nice plane, good build and I'm sure the grandkids are going to love it. Some put the left hand Torpedo's on the left inboard side of the fuselage so exhaust is down off the fingers and needle valve is located where it is easier to get to, still leave the tank on the right, will still feed proper.

gmeyers

I have several K&B's but only two greenheads - a 40 and 35. they both have different bolt patterns but they do both take 4/40 bolts I also have a newer version .28 takes 4/40 bolts but uses allen heads vs slotted of others. I have a .15 also but it won't let me take the bolts out - frozen in place but they have smaller headed screws. The 4-40 is a common size so finding them locally won't be a problem for you. My newer aero, duct fan and marine engines all use allen 4/40 too. Length of your screws may be a problem I have one similar to the .23 you have that uses 2 long screws (front and rear of head) then 4 short ones. I'd get some from MICRO FASTENERS who always seems to have good inventory and ships promptly.

GREG DOE

Someone correct me if I'm wrong, but my recollection of the K&B 15 Green Head that was marketed for an RC application had two needle valves, and not an "RC carburetor" as we now know as such. As I recall it had a venturi insert for the second needle, but that was a lot of years ago? I can only guess from the inquiry that Bob Harris has an engine that has had the venturi cut off, so some other brand of carburetor could be adapted? I had one of the dual needle valve 15's in the late 50's, but only flew it on controline airplanes.

GallopingGhostler

The 2 speed "carburetors" came about in the infancy of R/C, when proportional control was very expensive. Throttle on single channel escapements and even proportional was basically full throttle and idle or somewhere between, only two settings. Throttle was a temporary push switch on the transmitter, sometimes call quick blip throttle, because you simply quickly clicked it, engine would drop from full power to idle. Another quick blip of the throttle button would toggle it back to full throttle. You did it quick blip, because otherwise on escapement systems it might think you were giving it a rudder command. On analogue proportional systems, it could affect the other controls.

I even remember back in the late 1960's / early 1970's that Ace R/C had a quick blip throttle circuit that could be added to single channel R/C, and another for proportional say 2 channel R/C. By then, the two speed needle carburetors were gone and one would use a standard R/C engine.

Back in 1978, I bought perhaps the last cycle of Ace R/C's Pulse Commander rudder only system, this time on then "modern" wide band 72 MHz, with Adams Stomper magnetic actuator (their most powerful, said to handle up to mild .15 size aircraft) and with a KRD sequential throttle servo. Transmitter was modified with a temporary push button throttle switch. It would cycle the throttle from high to medium to idle back to high. Speaking of simplicity with half A and A sized aircraft, I had a blast flying this mode. I had this radio on a Ken Willard Top Flite 39" (990mm) R/C Schoolmaster cabin with a 1966 OS Max .10R/C engine. A bit powerful for a .049 plane, on full throttle it would climb out at a 45 degrees, on medium it flew like it would with a .049 with a mild climb, and on idle it was a blast to bring it down for touch and goes. Plane would stunt like crazy with the engine doing the rudder only aerobatics.

Sorry for deviating a little off topic. Although I fly multi today, I still at times long for the simpler times and the fun doing it.

UltimaThule

Hi Folks - I'm a newbie on here. I have acquired a Greenhead Torpedo .09 which was seized solid. I have managed successfully to free the piston and clean the engine up. It seems to have good compression and turns over smoothly. However it is missing the propeller driver and washer and I wondered if anyone could suggest where I might acquire spares. Any suggestions would be most welcome.

Dan Vincent

Hi UT,
When I see a "Seized up" engine reference it's usually the result of dried-up oil. Try placing the engine on a 60 to 100 watt light bulb for about 15 minutes and that will usually free it up.

Get some Marvel Mystery Air-Tool oil and squirt a few drops in the exhaust port and venturi to further free and lubricate the engine,

Other air tool oils will work but some will inhibit firing of diesels so I use Marvel for everything. Ace Hardware has screws, nuts and washers but the drive washer has a bevel and could easily be duplicated by a Machinist.

Two of the best .09's from the 1950's.

McCoy ,09 Diesel & K&B Greenhead .09

UltimaThule

Hi Dan

Thanks for your reply.

i eventually managed to free up the engine by soaking it in glow fuel for a couple of days and then by an application of gentle heating with a blowtorch. I have dismantled it and cleaned up all the components and now that its reassembled it turns over nicely and appears to have reasonable compression. I'll have to try to find someone who can make me a prop driver as I'm afraid I don't personally have the necessary tools to make one. Its one of the early engines without the modified exhaust port. Best regards - Roy

GallopingGhostler

UltimaThule , got any photos to post of your engine?

GallopingGhostler

Today I won a bid on a K&B .09 Torpedo, will have more to say when it is in my hands.


Photo appears complete with dog hairs and all.

GREG DOE

I love the Champion glow plug. I wonder what the going price for one is today?

GallopingGhostler

I have no idea on costs, this is the first time I have one in my possession. It does resemble a spark plug but has a glow element instead. Am told that it will get more RPM out of a standard modern plug. I gather that is from improvements in materials selection and design. Now that the engine is in my hands, it appears to be a low time or no time engine. The screws do not show any signs of wrenching. It has a nice pop when flipped. Engine is lightweight, too.

Sceptre Flight has 2 engine articles on it:
Sceptre Flight: The K&B Allyn Torpedo 0.09 (Aug. 1958 Model Aircraft)
Sceptre Flight: K&B Allyn .09 Engine Review (Apr. 1957 Model Airplane News)

Engine is light, only weighs 2.8 oz., about same as a Cox .09 Medallion. All I need to do is break it in and install it, go fly.

GREG DOE

I had one of the big brothers, a K&B .15, 65 years ago. I also had a Green Head .35 Good memories. Champion made spark plugs for the early ignition model engines. Then when the glow plug came on the scene they made them as well. They were very well respected in an era before cold, medium, or hot plugs were made.

GallopingGhostler

Greg, I also have a .35 Green Head, in fact, 2. One I cleaned up may be 5 years ago. A previous owner had for some odd reason cut the piston skirt to give the engine subport induction (SPI, like in the earlier Cox engines. SPI gives an engine additional puff of air admitted to the crankcase with piston at TDC, to increase air-fuel charge density to increase horsepower). However it was poorly done, almost 5/32nd inch gap, done with possibly a hack saw with a triangular wedge knocked out of the piston skirt. The other is a parts engine. Out of the two, I will make one good one.

This .09 G.H. oddly has the venturi needle mounted on the exhaust port side of the engine. (A few others I have seen photos of, show it on the other side.) This one must be an earliest one, I gather, due to the Champion glow plug and undesirable to have it on the exhaust side, a good way to get needling fingers singed by hot exhaust gases and exhaust in your face when adjusting needle. It will have to be mounted exhaust side up on a profile fuselage, so needle can be easily adjusted. The spray bar is a press fit, easily damaged if one doesn't have a decent press and setup to push out and reinstall, plus may have to Epoxy when installing since fit may be loose.

The .35 G.H. will be mounted on the left side of the profile fuselage, so needle is up and exhaust is down. It will also give more room to mount the fuel tank on the right side.

I have several other K&B .35 cross scavenged engines, their later Stallion that marched on after the G.H.'s, various years in both CL/FF and R/C. Those are less desirable and can be obtained at very reasonable costs, because they are slightly heavier and do not do the traditional rich 4-cycle to lean 2-cycle break and acceleration when entering CL stunt manuevers. However, just like in any engine, if properly mated to the right airframe and set up properly, they still do well. They also have the Meehanite iron piston, which is much more durable than Testor McCoy .35 Red Head soft iron pistons (I have a half dozen of those engines).

GREG DOE

All the green heads had the exhaust on the left side, which meant that it faced up when mounted on the right side of the fuselage (assuming the traditional anti-clockwise rotation). Generally modelers wanted the cylinder on the outside of the circle (fuselage), and the needle valve upright on a profile fuselage. The upright needle valve was particularly important on models without landing gear because if it was in a downward position it could get "wiped off" on landing. The GH .35 was a popular combat engine. As mentioned though, that needle valve location led to a lot of burnt fingers. Bottom line though is that the needle valve doesn't care which side of the engine it's on, so put it wherever it's most convenient. On a full body controline stunt model where the engine was upright, or inverted, the needle valve could be mounted opposite the exhaust. Having the fuel tank on the right side of a profile model, and the engine on the left side might create some serious fuel draw issues? When K&B resurrected the GH .35 as the Stallion they moved the exhaust to the industry standard right side. I have a Stallion, but no longer have a GH .35. I believe the parts are interchangeable so you might could salvage your SPI .35 with a Stallion piston, or piston and cylinder swap? My local hobby shop had a couple of used Stallions that could be bought for a song. Let me know if you are interested, and I'll check them out.

GallopingGhostler

Actually, the Stallion is not simply a right hand exhaust Torpedo. The crankshaft is larger diameter, which contributes to its heavier weight (8.8 oz.) versus the Torpedo (7.5 oz.). There was discussion on engine differences in either Stunt Hangar forums or Cox Engine Forums, difference in piston pins, in connecting rods, etc.

According to Sceptre Flight Engine Test articles, earlier Torpedo "Allyn" .35 had a slightly longer stroke of 0.74 in., which was shortened to 0.72 in. in later 1950's version.

The engine also doesn't do the rich 4-cycle to lean 2-cycle break entering stunts as with the other engines (Fox Stunt, Testors McCoy Red Head, I believe Torpedo too). Many of the standard available C/L kits were designed around the lighter Fox, McCoy, Torpedo that were lighter in weight. This just means that in order to maintain CG, I may have to shorten the nose a touch, which is fairly easy to do on profile fuselage aircraft.

Regarding fuel feed problems, I have not yet used a left hand exhaust engine yet. But, on profile fuselages, it is relatively easy to relocate a fuel tank if mounting location provides less than optimal fuel feed. In combat with the faster speeds, then I can understand where this would be more critical.

Reason for my purchasing Stallions is that they are in less demand than the Torpedoes, and since I am a sport flyer, I'm not interested in squeezing the last ounce of performance in an engine. Seems a good number of stunt flyers would prefer to simply avoid the Stallion .35. And, recently I came across an anomaly with one I won on an on-line auction. When I received it, found that the previous owner reinstalled the piston, steel fin cylinder and head 180 degrees out. This probably explains why the engine is hardly used. I removed them, made a new cylinder gasket, installed them correctly. Engine has like new compression. I basically got a new engine for a song.

GallopingGhostler

Greg, just wanted to add, and don't mean on discouraging you from doing that. Personally, there's enough differences in the timings of the engines, weights, run characteristics, etc., that give me an impression that parts would not simply be interchangeable.

Since I have only those 2 Torpedoes, and the parts engine is very grungy, it could be that once I do a thorough cleaning of the "parts" engine, it may become a solid runner. I've had stranger things turn good, like another .35 Stallion that was badly corroded but turned out good in 2018, that you replied to.

Regardless, these things are fun even to just bench run.