Hello All:

        Today I dug out an old McCoy .29 Sportsman circa. 1949 to get it broken in for use for OTS.  I have a Sterling F-51 built for it.

       The engine is "new" with a set of Bowman rings fitted.  I ran it vey rich with a heavy 9x6 prop until 5 five ounce tanks had been run through it.  I varied the speed from a blubbering 4 cycle to a blubbering two cycle.  The engine now cold starts on the first flip.  I have not run it wide open in a two cycle yet.  I am saving that for in the air in case the engine decides to go from a four cycle to a two cycle then I may have some room for error.

        Questions:

       How well will this engine perform as a power source for an OTS?

      What speeds may I expect with a 9x6 or a 10x6 prop?

       Anybody have experiences with these old McCoy engines?

       It did not like FAI fuel! It was much happier on a fuel containing 10% nitro.  I sinned and used oil content of 14-14 synthetic and castor.  All castor with a ringed engine may not be a good choice.

       I used a McCoy  Redhead .35 yesterday in a Sterling F-51 and it was a joy to use.  I have never used a McCoy before and this engine was really great.   I will go out on a limb and say that it was a better running engine than the Fox .35 Stunts that I have used in the past.  It started on the first flip, held a perfect 4 cycle and broke into a two cycle during manouvers.  It was very smooth running!

        Yes, I know that there are better choices but the cool factor in OTS has to be worth the trouble! Lol  I can always resort to using my very old Fox .35 engines but everybody has one of those!

 
       Suggestions or comments?

                                                                                                                                   Tia,

                                                                                                                                    Frank McCune

     Hello:

     Thanks for the replies.

      Ty, I have no idea as to what kind if McCoy that I have.  I doubt that it is a Testors as it is a 1950 model and not a 1949 model.  This model has a rear venturi that is angled up at about 45 degrees.  I like having the needle valve far away from the prop on this model. The nva on the Cub .19 is a real challenge to adjust as it is so close to the prop  I do not remember if the McCoy Sportsman had any ball bearings in the case.  I have a rear induction .36 that has two sets of ball bearing installed.  This engine ran very poorly on no nitro fuel.  When given fuel with touch of nitro, the engine came to life.  I will try fuels with 5-10% nitro to see how well it runs.   

      I also have a couple of the Sportsman? McCoy .19 engines with the straight venturi mounted on the rear of the case.  I ran these several years ago and they were very low on power due to very poor ring fit.  Perhaps they will improve with more running time on them.  It is very large loss now that Mr. Bowman is not making rings.  Perhaps some person will purchase his equipment and continue this very valuable service.

      Any idea as to how long I should run these engines to get the rings seated? 

                                                                                                                                 Be well,

                                                                                                                                 Frank McCune