Lazy Bee with Twin Gilbert Engines

pkrankow wrote:er...how do you start that?

I expect video of the starting too!
Phil

Very Carefully!

And yes...video from start to cras...er...landing !

Oh my......A Killer Bee    

Asymmetrical torque...hmmm. Depends on how ya mount 'em.

I'm thoroughly impressed and stunned, Kim.
That said...a wing pod or two could make it
a 3 or 4 banger. Yikes!
Looking forward to the report, should be fun.
Bob

Glad wee in N.C. are not the only ones Sufferen the humid crap that's going around ... YES this should be interesting  start to finish..........Roddie I may be able to comfort you with some chamber run give me till it cools the fu$$ off some      Kim u PM roddie about the PS mounts hes ready to turn some loose     Eric

roddie wrote:Hey Buddy!.. You NEVER cease to amaze me! The Lazy Bee has always appealed to me. Those Gilberts.. I don't know much about em'.. I don't see throttles on either one. What type of glow-head do they use? (it doesn't look like a std. plug) Are they still available? Are these control-line/free flight engines which run at WOT? It looks like you have an 8 x 3 prop on the .11? What's on the .07? Do you run Sig Champion fuel in them? I LOVE the exhaust headers!

You know; since I've been here at CEF for the last year or so.. there hasn't much (if any) discussion on expansion chambers/tuned pipes. Have you tried them?

BTW.. "Fred Flintstone" is one of my mentors!   

Yo Roddie !

I really don't know much about these engines. They were sold individually AND with RTF control liners in the 1960's. Mark has a section on them in his vast collection over on the .049 Collector Group.

I got four engines a few years ago from some fellow that had come across a mixed lot of them. This one just went without a bid a few minutes ago:



They've got their own glowheads, and I've read where there's not enough metal up on top to thread them for regular plugs, so I'm hoping these two hold up.

They just run 'till they're out of fuel, and I had them on a stand a while back, but can't find photos or video of it.

The .74 is gonna get a trimmed 6-3, and the .11 will get a chopped-on 7-4. I'll run each one and probably mess with a couple types on each to see what these things will turn.

The one thing that MAY give me trouble is the Gilberts' high-positoned spray bars. If they act like they don't want to draw from the Bee's regular tank, I'll rubberband a film-cannister tank up high between them.

I'm figuring Sig 15% ought to do it, but we'll see.

I just like the retro look about the things...looks like something "The Rocketeer" would use if he flew model planes! I'm sure some of the racing guys here have used tuned pipes, but I've never used them.

I'm probably gonna make a run over to the little airport at Cairo to fly MY version of the "Killer Bee"...since it might need some "wiggle room" !

getback wrote:Glad wee in N.C. are not the only ones Sufferen the humid crap that's going around ... YES this should be interesting  start to finish..........Roddie I may be able to comfort you with some chamber run give me till it cools the fu$$ off some      Kim u PM roddie about the PS mounts hes ready to turn some loose     Eric

Yeah, I was complaining to my Uncle about how, in the winter, we wait for some warmer air, then want it to cool down when it DOES get here !!

Can't gripe TOO much though...I've had a bunch of flyable days this year...and have been able to make use of them. Starting to fray my little flying machines...gonna HAVE to get back to BUILDING something eventually!

Will contact Roddie !

Thanks !

Aero wrote:Oh my......A Killer Bee    

Asymmetrical torque...hmmm. Depends on how ya mount 'em.  

Mah BIG rudder ain't skeered 'o no torque...asymetrical or othawise !!!!

That's a mighty big rudder!

roddie wrote:

Cribbs74 wrote:That's a mighty big rudder!

yaw.. I mean yeh, it sure is.. plus; it's leading edge swings out, like the old WWI Fokker "D" series fighters.. making it even more effective!

"Meet the Fokker!"

Kim.
The Gilberts should be happy on 15% nitro & lots of castor.  They have a ball & socket piston like a Cox.  6X3 is about right for the .074 but I'd probably use a 7X3 on the .11.  They pull good revs for a side-port with a small prop but really drop off the torque if they can't reach their comfort zone.  

There were about 3 different heads for the .074.  I've seen a number of pictures of the heads drilled and tapped for a standard plug but you have to get the right head.  One is too soft, one has too large hole when the centre post is removed and one must be ok.  It would take some experimenting to find the right one.  The .11s had little trouble with their heads, so the .074 heads with the same type construction should be good.  The soft die-cast .074 heads, which can't be tapped out, are very fragile and easily blow.

Starting, use a starter.  These start in reverse is seems 80% of the time. They run happily that way, but has the potential for some real interesting torque reactions on the Lazy Bee.   

Tank must be kept low. The original tank for the RTF planes sat down underneath the rear of the engine directly under the spray bar.  Fuel was drawn straight up from below.  They draw well and are easy to choke with the rear venturi for starting, but they will flood if the tank is level with the venturi.  With the angle of the intake, fuel will happily syphon until the crankcase is full.  So keep it low and let it draw.

Hope this helps and doesn't just confuse things.

Rod.

This is Great Info!  Thank You Rod !!!!!

STILL Learning Stuff Kim

Hoping Mark doesn't mind...I copied this frame from his .049 Collectors Group on Yahoo.  If you go there, click on "photos", then "album" and scroll through the great stuff 'till you get to the Gilberts.

This is SOME REAL retro stuff !!!!

The silly things run!  After gingerly testing the Gilberts' glow plugs and finding them good, I bolted the old engines up to my equally old EZ-Just test stand, and dragged my table out into the early morning humidity.

The .11 Gilbert started IMMEDIATELY, shooting the over-prime out it's little stacks and taking off.  As per Rod's suggestion to use a starter, I had the Hornet standing by, but the .11 started with just a casual flip.  I let it run gurgling for a while before taking it up to peak...which turned out to be  around 12K on it's 7-4 prop and 15% Sig.







The .074 was a little more cranky, starting backwards (as Rodney had warned) but finally lit off in the right direction with a flip-start, turning a very reasonable high 12-to-13 K on it's Cox 6-3...also on 15% Sig.





So, attention now turns back to that slab of ply, hardwood, and epoxy that I so generously call an "engine mount"!

Not a bad way to start the day !!!!!!!!

12,000 is probably a little below the .11s comfort zone. Slip a 7X3 on and you should pick up over 1,000 rpm. It may actually be better to run it slower than the .074 to balance it out. Why didn't you go for 2 engines the same size, or was it just the challenge of achieving the impossible?

Kim is a wiiiiiild and craaaaazy guy!

He also has a ton of experience so I am sure he will pull it off.

Ron

Oldenginerod wrote:12,000 is probably a little below the .11s comfort zone.  Slip a 7X3 on and you should pick up over 1,000 rpm.  It may actually be better to run it slower than the .074 to balance it out.  Why didn't you go for 2 engines the same size, or was it just the challenge of achieving the impossible?

Hey Rod !

I'm still digging around for a 7X3...may have to run to Tailwinds and see if they've got one in stock.

As far as my reasoning for using different-size engines when I could just have easily matched them up:  I COULD claim that I seek the intellectual stimulation of being the catalyst in the successful union in an aerodynamically asymmetrical relationship...











Or...it could be that I'm just weird...

symmetry is overrated

Phil  

pkrankow wrote:symmetry is overrated

Phil  

Too True !

Man I didn't know you could talk all that aerodynamic stuff too I ll take pic no. 2 she is slick  I was wondering the same thing about the engine size differences, but just figured Kim new what he was doing    

I wonder what effect the propwash from the forward prop might have in the performance of the trailing engine, noticing that they overlap?

getback wrote: I just figured Kim new what he was doing    

Oh, you good-natured, grossly over-generous soul!