Line up with faces. Bill's plane was fast...up until.

Don't hold me to this but some 3.7-3.9 second laps were clocked. Fastest plane was a Shy Fox, consistent 3.6 second laps. It did not race due to fuel consumption issues probably due to engine not being broken in enough and slightly rich NV setting. Probably not up to national standards but for club racing, fast enough.

**Lap times corrected. 

Bill,
Sorry to hear about the mishap! (I've done it, too....)

The 8x6 is definitely a better starting point for the FP in a SSR. I've run both APCs and MAs with pretty good results. Do you think your engine is still getting too hot with the smaller prop? I assume your fuel has got some castor in it to help with cooling. A touchy needle seems to be some kind of a hint. A major goal is to get your tank/venturi/needle/vent set up so that the ground setting is nearly the same as the flight setting and the tank runs evenly all the way to the end. If not, you need to work on the fuel system geometry. If so, congrats! That is a major "trimming" accomplishment on any new racer.

If the engine starts well cold (in the plane, not on a stand) but won't start hot then it would seem to be a fuel feed/priming problem or the fit has gone away on the piston/liner. One thing to try is to squirt the cylinder/head with a water bottle after you catch the plane and before you fuel it. If that makes things noticeably better, then you pretty much know how to improve things....  Of course, once you get good with the water bottle, you are qualified to pit a Fox racer, too.

Wish I had got in on some of that club racing!

Dave "McSlow" Hull

Hi Bill

Regarding your re-start isssues. The O.S. 25FP is very typical of a "sport" type engine. As such, they don't don't have a P/L fit that is particularly suitable to control line racing. In a nut shell, there is not enough pinch when at TDC, and not quite enough taper above the exhaust port in the liner either. Still, they can be made to work, and they are capable of single lap times of 2.75 sec's or 19.3/7 laps. However, in doing so, they will get hot, and the P/L won't have enough time to cool during a pit stop and recover what little pinch it had when cold. Adding to the problem is that during the fuel filling sequence, some fuel gets forced through the feed line up and into the venturi. If the engine does not start within the first couple of flips, that fuel has now hit our hot piston and partially cooled it, and now we have no more pinch at TDC and consequently, very little compression. As Dave Hull suggested, the water bottle trick (ie. squirting water in the head) during a pit stop will cool it enough to recover the pinch and allow a decent pit stop. The other thing you can try is to point the nose down and let the fuel drain out of the venturi before flipping. Keep in mind this is only a problem when the engine is HOT. I had to do this with my engine if it didn't start on the first flip or two.
There is a 3rd option, and one that doesn't require water bottles or fuel dumping, and that is to use the Brodak 25 with venturi opened to around 5/16", .330" to be exact. This engine has a much better P/L fit than the O.S. and is a bit faster all around as well. The best part is that with the AAC P/L and its tighter fit, they re-start! Some have said the P/L's wear out prematurely, but I haven't found this to be so in normal race operation. For racing, don't run it in with a stunt type 4 cycle, this keeps the cylinder cool and will cause extra wear on the piston. A fast, but rich 2 cycle is what you want when breaking in.

For props, the O.S. liked the APC 7.8x7 the best, and the brodak likes less load and wants to rev. Mine likes the APC 8x5 Sport. Dave Hull's Brodak likes the 7x6 Taipan.

I hope your Super Fly rebuild works out.

Regards, Les