Webra 25

Tell us what you do to get the best performance from your engines.

Moderator: hbartel

User avatar
boiler
Posts: 3336
Joined: Wed Jan 01, 2003 8:16 pm
Location: Ohio
Contact:

Post by boiler »

Have you tried Wildcat or Powermaster?
montague
Posts: 1639
Joined: Wed Feb 27, 2002 3:24 pm
Location: Maryland
Contact:

Post by montague »

Well, I'm no fuel expert, but I suppose that caster oil could change the foaming behavior of fuel. It does make sense if it somehow allows bubbles to form easier, like adding soap to water or some such. I haven't done any testing.

I do make sure to soft mount my fuel tanks in my B and 2610 ships. The SSC planes, I just have the tank inside the foam fuse with no padding, and I don't have any problems there, but it's possible the smaller engine vibrates less, and the 3oz tank might help, I don't know.

Maybe I'll have to swap engines around again, and see if the plane I had foaming problems with will not get them with differnet fuel. That would be nice. I have a nice, new looking 2610 fuse that foamed like crazy with the webra (while my other webra equiped plane has no problems). I fixed one by cutting out the tank area and putting foam padding around the tank, but I didn't want to do it to this new plane, so I just put a slower motor in there and the foaming went away.

I can get a gallon of Cool Power 15% and I have some PowerMaster 15% around here in reserve, I just don't have time to actually do the testing any time soon.
sgilkey
Posts: 2351
Joined: Mon Mar 19, 2001 8:26 am

Post by sgilkey »

Kirk, funny you should mention these issues, as I had the opposite experience, I have hardly ever had foaming problems with my B and 2610 ships, but have had all kinds of problems with my SSC ships- including different airframes. All my SSC ships have needed to have the tank carefully isolated to solve foaming. B and 2610 are all basically crammed into the fuselages or strapped to the side and no foam problems. I do balance my props. I'm sure it's a resonance issue, something about the rpm i'm running my SSCs at is exciting the fuel system. The only time i had a real foaming issue with a B ship was with one of my first B engines, which was an iron-piston 28F. On a 9x4 that sucker would vibrate pretty well and i'd get foaming. Switch to a 9x5 to drop the revs down, and it ran consistently as any other engine, on the same plane. SO folks who are having a foaming issue, if you try shifting the rpm with a different prop, it might solve it- useful if you are in a pinch on contest day. I usually bring along an assortment of props "just in case".
montague
Posts: 1639
Joined: Wed Feb 27, 2002 3:24 pm
Location: Maryland
Contact:

Post by montague »

Well, my fuel draw became a lot more consistant with the latest changes to my SSC plane, basically lowering the engine about 1/2" or so and mounting it upright instead of at an angle. For all I know, I'm having all kinds of fuel foaming, and just setting the mixture rich enough to run on air bubbles [:D]. Or it could be the Mags vs the LA's again, the Mag has a shorter stroke than the LA, which might or might not affect vibration levels.

I do agree about messing with the RPM and prop choices to help make an engine/fuel system more stable and easier to set up.

I've also finally managed to "fix" my "ear" for setting engines. I used to wind up setting my engines a hair too lean on the ground. I now set all my engines, but espcially my Webra's (look, I'm back on topic) on the rich side, then let the G's lean it out for me in the air. That's how I get that "rocket through the corner" thing going on the Firebrand that you guys noticed last year. The OS's do the same thing, but not as pronounced as the Webra does.

Also, when you talk about a Webra being "peaky" or touchy on the needle, keep in mind that I run Mag .15's in SSC. Part of setting their mixture is to tap the needle here and there for "fine tuning". Forget a full click. So, by comparison, the Webra has a nice broad needle, and the OS, man, it feels like I'm turning that needle forever before I notice any RPM change at all. Sheesh, it takes forever to get those OS's right, all that turning. [:p]
User avatar
Air Scharnell
Posts: 650
Joined: Fri Jun 10, 2005 3:59 am
Location: Colorado
Contact:

Post by Air Scharnell »

Boy I didnt think I would get all this info on just 1 problem [:)]

But as RH , stated with the Cool Power [}:)] 25% has solved many problems. With not only the Webra, but an OS , and a Magnum as well.
As for Scott's prob with the larger APC.
You know that how all this started. I was flying a 9.3x3 at the last event. My kid thru me a prop for a spare, but I made it a 1st run.
That round I snagged a streamer and lost it in a flat spin[}:)]
Recovered on high rates and barely managed control, till the dirt nap dive away from the safety line while inverted. This will take more testing for the smaller APC.
I agree that the MA is too flexible, for the Webra when it's turning over 18k. This led me too APC props. We had a pilot show last month that has the same probs with Webra and APC and an Irvine.
He flys in Nebraska or where ever the streamers are flowing.

For the fuel issue: Morgan's mix on Omega is 17% lube 30/70 the castor being the 30%/ High Viscosity synthetic being the 70%
That I found right on there web site.
Cool Power is all High Vis lube at 17%
For other fuels Im not sure. I havent found Power Master locally.
Unless I order it direct from factory.
Where was I going ( dog had too go out ) [:)]
Oh yeah the SSC issue with foaming my oldest kid just built a Lanier ripper, with a OS la.
As per RC report I removed the baffle checked for flashing, while my kid sealed the back plate and changed out bolts, too cap socket.
The last run was still foaming with 10% cool power.
After checking with some other pilots locally, we will try velcro on the tank. Changing the tank as well.
My kid built it not me. He's still learning [8D]
Ive not flown SSC , just Open B.
Our 1st run was with Omega , and boy was it FOAMING. On the 3rd run I switched too Cool Power 10% and the foaming stopped till half tank ?

Oh by the way Scott my Webra prob might have been a jammed collet.
So I dont have too send it in yet [8D] Will test it this saturday.

Now that I totally tore the engine down mutiple times trying to get the thing turn right, I found that the Crank hit hard enough to shift.

I will try the kombat Kan theory thou.
So far I have been marking where it would hit the back of the can moving it back 1/8 of an inch and starting there. SO far like I 1st stated in our thin air I tached it at 18,6k with the MA man was it movin for Colorado standards.

Well I should get back too work those planes dont fix themselves.
Thanks again for ALL the GREAT ideas.

Frank S
User avatar
Air Scharnell
Posts: 650
Joined: Fri Jun 10, 2005 3:59 am
Location: Colorado
Contact:

Post by Air Scharnell »

Oh Kirk ,
It's true the Magnums are touchy.
I have a few in different sizes, and there all the same. Best thing we found was too heat srink the high end needle.
But you can change the rev by a touch too the needle.

I know I can hear them NOW
" GET TOO WORK DAD "

Chat later ,
Frank S
montague
Posts: 1639
Joined: Wed Feb 27, 2002 3:24 pm
Location: Maryland
Contact:

Post by montague »

I just got a pair of new Webra's in the mail, and I just noticed something really strange. The needle values are differnet on them. Has anyone else seen anything like this? I have a couple Webras from last year, and their needles are all like the finer toothed one. Does anyone else have one with the corser teeth? It would seem those teeth might, in fact, make the engine touchy.

I did unscrew the needles, and the corser toothed needle's point was a more gradual taper and it had a thinner tip, which but itself would result in a finer adjustment. But I have no idea if it's enough to make up for the corse tooth adjustment. Which needle does yours look more like?

Image
User avatar
Air Scharnell
Posts: 650
Joined: Fri Jun 10, 2005 3:59 am
Location: Colorado
Contact:

Post by Air Scharnell »

Kirk,
I will check when I get back, in town......
We got ours this year, from Horizon not too say they have OLD inventory.

As for another flaw I have found with a WEBRA.........
This was my 5 event running the WEBRA, and of course in round 2 took a streamer cut and a mid air right after no recovery, and SMACK.
Again the collet jammed, the crank. WIll have too rip it down again.
Whats really strange my son had 2 midair dirt naps and his is fine.

Will check that needle valve thou.

Oh yeah my Webra turned 16,100 on Cool Power 25% turning APC 9x3
Kombat Kan, Mac header, on a Hayes suction tank
We were flying in Sterling, Co. roughly 1000 ft lower that where we normally fly.

Frank S.
RH
Posts: 970
Joined: Fri Sep 21, 2001 4:30 pm
Location: USA

Post by RH »

Frank, I was getting 16k out of my back up Norvel on a stock muffler. Surely those Webthings were turning more?? I didn't even tach my FX, just sounded like the 18+ it always turns.

rh
montague
Posts: 1639
Joined: Wed Feb 27, 2002 3:24 pm
Location: Maryland
Contact:

Post by montague »

So, how to the needle valves look on the other webras out there?
User avatar
Air Scharnell
Posts: 650
Joined: Fri Jun 10, 2005 3:59 am
Location: Colorado
Contact:

Post by Air Scharnell »

Hello Kirk,
Since Im working on the Webra again you are correct.
We have 2 different needle valves.
The shiny one has a wide tapper compared too the dark colored 1.
Check your taper and you will see the threads are different as well.
Will be flying a club meet today so we should be able to test the RPM.
On either engine.

Frank S.
montague
Posts: 1639
Joined: Wed Feb 27, 2002 3:24 pm
Location: Maryland
Contact:

Post by montague »

I didn't notice the threads being differnet, and I'm pretty sure I was able to screw each needle in to the other carb.

I'm going to break in these 2 new Webra's this weekend. Let me know if you notice a running difference between the 2, and I'll get back with my results.
sgilkey
Posts: 2351
Joined: Mon Mar 19, 2001 8:26 am

Post by sgilkey »

just got around to checking Brian's today, the one he got last year has coarse knurl, the two he got over the winter have fine knurl. the two new ones have yet to be in the air. which give you some idea of how prepared we are for the nats.
User avatar
Air Scharnell
Posts: 650
Joined: Fri Jun 10, 2005 3:59 am
Location: Colorado
Contact:

Post by Air Scharnell »

Well after 2 rounds and a dirt nap thanks too a midair.
The Webra on my Avenger, was turning over 16k, with an APC 9x3.
Cool Power 25% with a kombat kan.

My oldest son is flying a Go Devil his was turning over 18K.
MA 9x4 on same fuel and kombat kan.
The needles are still sensitive just 1 click and it will lean out in flight.
Better too fly on the rich side but then you have a kid telling you I cant chase anyone, its too rich and fly's like a slug.
it was in the 90's here today did that have something too do with not sure.

Will do more testing in the next month, while we prepare for the next big event out here in the WEST.

Frank S
montague
Posts: 1639
Joined: Wed Feb 27, 2002 3:24 pm
Location: Maryland
Contact:

Post by montague »

Well, I just got back from breaking in my 2 new Webra's (I'm not doing much better, Scott).

Both engines ran just fine, no problems with leaning out or anything. RPM went from "not much" to pretty darn good by the end of the day as the fuel was burned. I burned about half a gallon of fuel today, just flying them one then the other.

The RPM was down because I actually followed the Webra instructions a bit, and used some fuel with higher than normal oil content. I took some fuel I had sitting around that was actually a mix of a few differnet jugs and brands, then added a few more % of caster oil to it. I figure when I run my normal stuff, I should get a few more rpm, and they will run just fine. As it was, in level flight, the engines weren't quite getting on the pipe in level flight, but in a dive, they'd come on the pipe and the acceleration was impressive.

I never got around to taching late in the day, when they were picking up, but both were turning around 17k on the ground with the APC 9x3 earlier. I'm guessing about 18k later.

Btw, watch those MAS props on the Webra. One of mine turned that prop over 21k, and the prop was flexing all over the place, and the plane didn't fly that well. The APC 9x4, 9x3, 9.3x3 or GRS models (George Cleveland) props are all better choices than the MA prop on the webra, I think.
Post Reply