Bump!  Steve

Thanks for answering, Joe! Well, launching at same rpm (but in more on the NV), it flies about the same speed...but I don't check lap times. I think they are highly overrated as a goal. The plane has a minimum speed where it flies well, and that's about all there is to it. But the engine is obviously running leaner, also observable by the way it quits now...slight leaning out, not for long, and not all that obvious a signal. I've had to reduce my fuel load about 10-15cc's on the same fuel.

I'd like to richen the engine up and burn a full 6 oz again. It's a clunk tank and holds a bit more than 6. Using my mustard pump, I can accurately put in 6.0 even. It's kinda surprising how different the plane flies with the 3 blade CF prop...took some retraining of the pilot! Part of that would be the CG shift, but a lot is just the prop. In general, I like it. But I need to get the engine running richer and increase the fuel burn. I'm just not sure where to go with the prop. I have one more of these props, but it's a full 12", and on the PA .51. I'd like to leave it there, and certainly don't want to squander either (pun intended!) of these.    Steve   

Ok, Keith, you're a Pit Puppy!

I haven't figured out yet why electron burners want everybody to change to electrons. I'd rather eat worms! Yes, that's it, worms. Yucky worms and yucky electrons. Ewwww! Castor oil is good for the skin, you know...  Steve

Why not try pitching the prop to 4.25?

Well...I thought this was the prop from the PA-51, so thought it'd be ok, trimmed to 11.5". Turned out it wasn't the same prop. Plus, I'm not very good at re-pitching props. It's the logical thing to try, of course. I appreciate your suggestion.  Maybe I can get to it by Thursday night; at least I know where my pitch gauge is. I think. Steve

Reporting back after pitching the last 2" (8-10-12 stations) to 4.75". It reduced the launch rpm to 10.30K to 10.35K and pulls much better in the verticals and overhead stuff (previously launched at 10.5k) John Leidle launched for me both rounds at The Scobee, and clocked my level laps at 5.2 sec. both upright and inverted. The engine run is still too long on 6 oz, landing at 7:55 on my first round. It still doesn't give as strong a signal of shutdown as I'd like. Fuel was changed to 10-22 made by Howard Rush. I'd like to just pump in 6 full ounces, and I want a strong shutdown signal. I have deleted the pipe pressure and instead have a tube run from the uniflow into the backplate cavity, hoping for a constant pressure. I like this, and see no reason not to run it this way all the time. Brett says he has this option for the wind, but why not all the time?  

Since changing trucks ('06 Tacoma to '08 Chevy), I have been transporting the plane in the backseat, with the nose down. Previously, I had it on a shelf in the back of the truck bed/canopy. This nose-down thing is a bad deal, as a lot of oil runs into the engine and locks it up. I've never bothered with "burping" the engine before. I need to make a trip to the hardware store and get some PVC pipe and a bunch of fittings to make a new rack for the back of the truck. I can't find the one that I used in the '97 GMC...but it may be in the compressor shed or just lost in the garage. It could be in there, somewhere. I may have given it away, but I hope I find it. I have a new one sketched up to figure out fittings and pipe lengths.   Steve

 

John, I knew the exhaust oil residue would run into the engine, but just didn't think about it, and didn't have an alternative way to transport the model. Oldtimers kicking in?

I'm not sure I understand what you're saying about the 4 stroking and shut off signal. Are you saying that I have a lot of prop load or too much prop load on the engine? That was the original question I posted.

I think I can tell if the engine is loaded too much, but don't know what signs to look for if not loaded enough. As the .46VF is now, I think it could be a little on the heavy side of ideal. Seems to me like if the engine is running rich, it'll come on strong as it gets to the last lap or three. If it's running pretty lean, it should just run ok until it's out, being an AAC. That's what I'm seeing, pretty much. I'm thinking about modifying the blade tips to scimitar shape to reduce the load, instead of just clipping the tips. If it works, fine, if it doesn't, I'll clip them more and repeat the scimitar shape again. Does this sound logical?  Steve 

PS: I just dropped $46 on PVC pipe and fittings at McLendon's...