planknheli

hey guys,
i`ve got a brodak baby clown arf with a texaco .049/7x4 engine prop combo & 35` x .008 lines. do you guys see anything wrong with this combo??
thanks,
conk

build light

sounds like a winner. Fire it up!

Robert

CLpilot

My Feedback: (1)

I would go with a 5X3 prop but seems like you are ready to fly. Give it a shot and let us know.

Jay

planknheli

thanks for the quick replys robert & jay!! i read somewhere the texaco could turn a 7x4 because it was a high comp. engine. i need to tach it with a 6x3 & a 7x4 & see which i like best.
thanks again guys,
conk

build light

Actually, the Texaco engine was designed for fuel efficiancy. It should fly the plane ok but not give the plane its best perfomance.
This should not keep you from flying at all but to give you a start. Yes the Texaco will swing a 7 inch prop.
It was designed to do so
If it is a Texaco version and has the Texaco glow plug, the glow plug should have 5 cooling fins. One more than the standard glow plug. This is to help dissapate the extra heat this engine will have from the lower RPMs.
No other Cox .049 will give its best perfomance on a 7 inch prop.
The Tee Dee engines were the ones that have high compression and the inside of their glow plugs have a Hemispherical shape.

Do you have another engine to use later on?

Robert

build light

For some real info from the gut who designed the Texaco engine read this:
http://www.freeflight.org/community/...7/WHAM7-07.pdf

The text begins on page 0ne then on page two are the club minutes and continues on page three.
This should not be the last word on the subject. I hope more will follow and air their opinions as well.
I will be back too.

Robert

planknheli

robert,
yes it has the 5 fin head. the engine case is black not natural colored like the one in your pic. the only other engine i have is a sure start .049 . what would you suggest as far as a different engine? i only want a slow easy flying plane if that`s possible?? i have a flite streak w/ a la 25, a sig primary force w/ a la40 & a coroplast w/ the sure start. i really like the cox engines especially the ones with the fuel tank built into the motor.
thanks robert,
conk

planknheli

thanks again robert , thats a good read.it has me worried though because i have my needle at about 2 1/4 turns out.
conk

build light

Quote by Conk:
"i only want a slow easy flying plane if that`s possible??"

As you may have read, the idea was to use the high compression along with the larger prop and large tank to get looong engine runs for a particular event.

Have you built the Baby Clown yet? If not, build it light as you can and sand it a lot!

Actually this combination you have is not thje ideal combo, however it should give you ease of starting and a docile or as you say slow and easy flyer.

Robert

build light

Another thought...
You will probably do better with the Sure Start engine and it is easy to tone down. Lots easier than trying to get more out of the Texaco.

For instance use the 6X3 prop on the Sure Start and lean it out good and back off say quarter turn rich so as not to get top RPMs.
Still too much? Remove the prop and put it on backwards.

The Texaco really is a purpose built engine design.

Robert

Phlip

I'm a bit mystified by the desire for a slow, easy-flying C/L plane. I understand that desire for R/C or F/F, but with C/L I always want a plane that has the oomph to keep the lines taught and do stuff ... loops and wingovers at the bare minumum. Otherwise it's just round and round (and round and round and round ... [:'(]

I'd want the peppiest engine I had on a C/L plane, particularly a 1/2 A class. If it's too fast, change the prop and/or lengthen the lines!

Phil

gcb

Toward the last, Cox mixed and matched many parts. AFAIK the black tank (plastic?) was used on the Babe Bee, Texaco, and Black Widow. Not sure if there was ANY difference, but it may have been in the intake size. I think they all used the Sure Start front end.

Bear in mind that this is hearsay from posts I have read, not facts. The only engines from the last days are some Sure Starts.

George

build light

Lots of good info on Cox engines here:
http://en.wikipedia.org/wiki/Cox_Model_Engines

http://www.mh-aerotools.de/airfoils/cox_frameset.htm
And at ones discretion here:
http://www.coxmodels.com/Aboutus.asp

Robert

planknheli

update, flew the plane w/ a sure start engine. the plane flew great but the engine didn`t do as well. the needle kept moving so it wouldn`t run good for very long. i guess the vibs. were doing it. it finally broke the needle off in the engine. i bought a black widow for it & i haven`t flown it with that engine in it yet. i bought a sig skyray kit for a babybee. i have the engine & i`ll pick up the kit tommorrow.
conk