How much run time do your Black Widows get on 8cc?

It has been since i gave the new piston/cylinder a run in since I ran a full tank through mine. Mine runs all the way to the scene of the crash/es on the nose of the farcebug And it`s never more than about 40 seconds so I have no idea what the run time is on a full tank
I run a 3 blade on that 1 because I`m not after max scream with that little plane:14"span,15"L rudder tip to spinner;she is fast enough at that

Jaspur_x wrote:...Mine runs all the way to the scene of the crash/es on the nose of the farcebug And it`s never more than about 40 seconds...

Do you need more practice Jaspur?

Next time I get out to the shop I'll time a couple of runs with a 6x3. I have two ready to go and one runs a lot faster than the other. I'm about to start a new thread about speeding up the slow one.

I've got a black widow that I swapped out the piston/cylinder with one of Bernie's SPI piston/cylinders and have a Kavan tank extender. It is a real screamer but has never run more than 2 min 45 sec. Doesn't run for long but the ringing in my ears sure does last for a long time.

Bob

fit90 wrote:I've got a black widow that I swapped out the piston/cylinder with one of Bernie's SPI piston/cylinders and have a Kavan tank extender. It is a real screamer but has never run more than 2 min 45 sec. Doesn't run for long but the ringing in my ears sure does last for a long time.

Bob

That's the run time with the extender? If so, then I think mine sounds about right.
I've toyed with trying a new SPI set, or maybe one of Bernie's Tee Dee sets, but I kind of like having it original since it's less than a year out of the box. Did the new set increase the performance?

That time is with the tank extender. This is an old engine (mid eighties) with lots of run time pulling gliders, GLH's, Humers and lots of other planes. I never tached it when it was in its prime but I know when I pulled it out of more than ten years of storage it was just an okay performer. The SPI piston/cylinder really perked it up.

I usually get around 3 minutes.



The engine in the video ran for about a minute or so while I adjusted the needle and turned on the camera before I actually recorded it. I'm actually quite amazed the engine runs as well as it does, the reed is very worn and it even has small "dents and creases" in it but I have always left it alone because it runs so well (if it ain't broke, don't fix it). I usually don't run them on 35% nitro but that is all I had at that time so I used it anyway. It always glows like that, no matter what fuel I use (5% or 35% nitro), the head is very bright itself! I will be recording all of my engines this spring.

I can see 3 minutes with that one, it's running pretty far off peak, or either it was swinging a big prop. I'm running mine full blast with a 5" prop when I've taken those times. I'll video mine from crank to empty tomorrow. I'll make you cringe as as you watch me hand hold the test block so the pickup is pointed to the bottom.

RknRusty wrote:I can see 3 minutes with that one, it's running pretty far off peak, or either it was swinging a big prop. I'm running mine full blast with a 5" prop when I've taken those times. I'll video mine from crank to empty tomorrow. I'll make you cringe as as you watch me hand hold the test block so the pickup is pointed to the bottom.

It does have a 5x3 prop. I really didn't want to lean it out too far with the 35%, first run after sitting on a shelf the previous winter and...oh what the hell, it needs a new reed. I'll swap the reed out tomorrow and run it in the garage. I can usually never get over throwing away any cox part, broken or not. I have a whole drawer full of bent and worn reeds, broken cranks, over corroded early 1956 Babe Bee parts (how unfortunate...), burnt heads, old crankcase gaskets, fossilized pickup tubes, ruined pistons, busted carb bodies and much more.

Haha, yeah, I've finally gotten better. I had to throw a bunch of parts out when my son, with all good intentions, left a bunch of old 5cc Bee tanks, crankcases(with shafts), cylinders and pistons in a pot full of fuel to soak, and forgot to tell me. A month later they dried out and were a gooky corroded mess. I hated it, no telling what I could have restored. But it's all gone now. I have enough to survive as I'm not a collector, just a flyer, but it still hurt. All I'm wanting for is I can only find 2 metal backplates in all my stuff. I really wish I knew where they went. I'd never use a plastic one if I could help it. I'm sure I could get some on the bay if I wanted to spend the money.

Also I've found my reedies don't like the 35% as well as the tamer stuff. The GPboy runs better than any of the SIG too. But the TDs love the Sig 25 and 35.

Rusty,

I ran my widow tonight with a 6x3 and came in at 2:10. I had just installed the metal backplate, and I am not sure the pickup tube is in the correct position. It's a little hard and needs replacing.

2:10 sounds like mine with a 6x3 on the bench, a little less in the air. I'll run them again tomorrow and see, but for a nice fast running engine it sounds like mine are okay. I think we might have had a case of oneupmanship and exaggeration amongst the RCG guys. Just another case of my curiosity.
My fuel always runs out before my fun does. Pretty soon my Li'l Satan will be the only one with a BW on it.

[quote="RknRusty"]

Jaspur_x wrote:...Mine runs all the way to the scene of the crash/es on the nose of the farcebug And it`s never more than about 40 seconds...

Do you need more practice Jaspur? Maybe a bit of flying practice would help me out lol BUT so would a plane built correctly that would actualy fly would be much more help lol

I noticed on that plane that the eleator stab was not horizontally level ......off by about 1/2" from ont tip to the next. I did attempt to repair this construction error, and am awaiting the weather to allow another flight attempt lol

I'm crazy too, I find holding the 2x4 while the engine is running fun.

[quote="Jaspur_x"]

RknRusty wrote:

Jaspur_x wrote:...Mine runs all the way to the scene of the crash/es on the nose of the farcebug And it`s never more than about 40 seconds...

Do you need more practice Jaspur? Maybe a bit of flying practice would help me out lol BUT so would a plane built correctly that would actualy fly would be much more help lol

I noticed on that plane that the eleator stab was not horizontally level ......off by about 1/2" from ont tip to the next. I did attempt to repair this construction error, and am awaiting the weather to allow another flight attempt lol

The elevator on my Satan was about 1/4" from tip to tip, higher on the inside. I was so mad I had overlooked that while the epoxy set. I flew it anyway and it was fine. I fixed it though. When my BW sucked air on a loop... as it so freakin' loves to do, I had the "opportunity" to repair it. I wish I could put an external tank on that plane, but there is nowhere to put it. Especially since I added a spar right on the C/G.

My video will supposedly be on Youtube at about 1:45 Eastern US time at this address:
https://youtu.be/Sh0QBWDEYs8?hd=1

I'll have been in bed a while by then. I'll supply the HD link tomorrow.

Ah, yes, it uploaded as I slept. The link in the post above works now. I haven't been to the computer today until now.
And now I'm gone again till later. See y'all this evening.

RknRusty wrote:Well I had a new happy revelation tonight. After figuring out why one of my BWs was slower than the other, I slapped a new style SPI set with the short piston on it and it runs as fast as it should now. Not only that but it's obviously more efficient because my full speed run times are now 2:25 as opposed to 1:55 - 2:05 with the old #1 Black Widow cylinder (as seen in the video above). And as a bonus, it's much easier to needle. It gives almost an extra half minute more flying time with the same speed. The new style slit SPI cylinders work as advertised.

Proven results and I didn`t even have to break my new pieces out of the package yet.......I even got a throttle specifically to complement those spi cylinders

I'll have to fly it to see if that light piston develops as much torque as the heavy one. Especially stunting with a longer prop than I would use for just speed. But I have plenty of videos to compare the engine sounds with, as well as the good ol' pull on the lines. If it doesn't, I think a high compression head will make up for it. Y'all all know by now I guess a lot, so some of our better engine experts might have an idea about that. I'm not getting any flying time during the holidays, but I hope to sneak out for one before too long.