I have a new Super Tigre G21-46 engine for which I need a manual or break-in instructions
No real need for a manual, but you could try the various swap meets around your area. By Swap meets, I mean the ones intended for Model Airplane enthusiasts, not the "Generic" redneck meets. But on to your dilemma:
These engines were designed in the early 60's and only became popular in the 70's. For the Control line stunt guys, this was the engine "To Have" for a time. Out of the box, they gave tremendous power for their weight and gave the consistent type of run the Stunt crowd craved. I can only assume you intend to use it in an R/C application. You may consider listing it for sale if it's NEW in BOX, or at least New (w/o box). They can fetch a nice price online, especially Ebay.
Be that as it may, here's the break in. This engine features a Chromed liner, but is NOT ABC/AAC. It has a ring that must "seat" in order for it to provide good long lasting service. It's not a High reving motor, quite the opposite. It likes to run in a mid-range of no more than about 13.5 -14,000 Rpm. It can also, once properly broken in, swing up to a 12 inch prop, but it won't spin it fast, certainly not like a modern OS .46AX or .45FX, The internal timing of the venerable G21/46's is really mild... Think of a FOX .35 on steroids, .....real steroids !! You can also think of it as a 2-stroke engine, that can behave like a 4-stroker. Don't put a prop on it and go for that MAX RPM scream. It'll scream alright, right before it breaks....
Definitely use CASTOR oil in your fuel to break it in. Synthetics will gall the piston liner unless you are extremely careful. Read that last statement again. VERY CAREFUL. Use no more than 5-10% Nitro, at least 25% Castor (for break-in) and the rest Methanol. This fuel is usually special order from most Hobby Shops. dON'T TRUST WHAT THE HOBBY SHOP COUNTER HELP WILL TELL YOU, UNLESS THEY HAVE FIRST HAND KNOWLEDGE OF THIS MAKE AND MODEL OF ENGINE......Usually They will try to sell you something that is ALL Synthetic. Don't bite at this. A $18 gallon of fuel will ruin a $140-200 engine. Pristine examples can sell for that much...This engine was probably made before they were born. It MUST HAVE Castor oil in the fuel. Run the engine in short 2 min. runs, always in a rich sloppy 4-stroke type run. Don't lean it out much. If you lean it so that the sound is a steady 2-stroke "Song", then richen the needle setting until it sounds strong, but rich 4-stroke rhythm. 2 Minute runs, cool completely, another run, repeat until you have about 1/2 gal thru the engine. Use a 10-6 prop for break-in, or a prop cut down to 10". After you put a least a half gallon of fuel through it, you can lean it out progressively, but err on the rich side. This takes some time, but the reward is pure magic.
After break-in, you can substitute some (I said SOME) of the oil for synthetic, but not much. Oil content should be at least 22% with at least 18% of the oil as Castor. Lot's of stunt guys used up to 25% oil, strickly for cooling and consitency of the run. It also prevented any sort of damage if you got the needle too lean. Parts are Very very difficult to come by, usually only from the expert motor shops and special re-work stunt guys.
So ask yourself, Do you still want to run this engine, or sell it to a collector or someone that is familiar with the breed. I have 5 of these. They are going in the coffin w/me when I leave this Earth. I will sell most all of my hobby stuff before I'll part with these jewels..
Jul 13, 2010 |
Dolls, Playsets & Toy Figures