How to start the RCV
Brian, et all:
Just an update on the RCV 90 and the H-9 Mustang. I finally decided to take the engine off of the test bench and am in the process of fitting it to the Mustang. This is no easy task as the RCV is about 1/2" shorter than the YS 91 that I had in the plane. I had to make a spacer plate to get the engine to the correct length to clear the cowl. What I did was to make two spacer plates of 1/4" ply each. I cut a good portion of the center of the rear plate out so that I could fit the RCV backing plate (couldn't fine any M4 x.7 screws long enough to go thru the 1/2" ply + the firewall + the thickness of the engine mounting flange. Anyway, once I got the rear spacer cut out I glued the two plates together to form a spacer of the correct thickness I began the process of mounting the spacer and engine to the Mustang firewall.
My hope is to get all of this done in the next few days. I have ZInger 16"x10" three and four bladed props on order and they should be here by Thursday. My hope is to get the plane in the air over this coming weekend. I have about 15 flights on the P-51 with YS 91 power so I should be able to tell fairly quickly if the engine is going to fly the model any better or worse than the YS.
By the way, I ran the RCv for about 30 minutes on Saturday (this makes a total of a hr and 50 minutes). Incidentally, all of my rining has been on Powermasted 10 % nitro with 18% oil. The I ran fifteen minutes at various throttle settings between 3800 and 4800 RPM. The last fifteen minutes we spent mostly above 5000 RPM. Using a Zinger 18"x6-10" prop, I tacked the engine at 5350 RPM. I spent some time leaning the engine out on the tip end and adjusting the carb bottom end. I did notice that with the above prop and the engine at full throttle (5300 RPM) the needle seems rather sensitive. I found that a movement of about 6-7 clicks take the engine from the slobbering rich side to the lean side (it falls off rapidly and drops RPM). This was rather surprising but I think it is managable. We shall see.
One other thing about the engine. Once I had about 1 hour on the engine, I could hand start it quite easily. I simply pulled the prop thru about 4 or 5 times and then attached the ingiter. One or two flips and it strated up.
I will keep the group posted on the progress of the experiment.
Later,
Ed