I would like to convert my RC engines to Control Line.. Does anyone know of a good source for
venturis and NVA?? (K&B 40, 61, 65. Super Tiger 40, and Towerhobbie 40..
Thanks;

[email protected]

There is a source. See if you can find it with Google. I think it was Stuka Stunt or someting like that. The TH 40 was the more favored of those. The ST 40 is rather highly tuned and will tend to break out of 4 cycling and run away in a lean 2 cycle on you. The K& B's tend to be that way also.

Enjoy,

Jim

Yes W8ye is correct. Leonard at Stuka is one of the best at venturi conversions.
I have ordered a few from him in the past and everything worked great.
I have sent you his email address. Just email him the engine make model and displacement. He will even most likely tell you what fuel/oil to run in it and how to go about tuning it I know he always does in his replys to me.

Here are some from Tom Dixon, another very good C/L source. He lives not to far from me. I considered getting back into control line. I still may. I built a Brodak Lightning Streak a few year ago, but lost the knack of triming the two dimensions that you cannot control.

http://members.tripod.com/adm/popup/...90cf715b21d4af

Dave,

Try

http://www.clstunt.com/

for Stuka Stunt Works. Click in the link on that main page entitled "More Products" to find pricing information as well as what venturis annd NVA's are available from that source.

I, too, have purchased from Leonard and have had excellent service and product.

Have fun with the conversions. The Tower Hobbies .40 (OS FP .40 clone. Parts are interchangeable.), in my experience makes a good sport/stunt engine, but unless modifications are made to the deck height it only works well when run in a rich two cycle with a lower than normally pitched prop (Try an APC 10.5×4.). That engine will not do a traditional 4-2-4 run well unless so modified. I have no experience with the ST .40, but in all likelihood, if you run it the same way, i.e., two cycle/low pitch, it will work out as well.

Good luck!!.

A couple of points to consider:
Assuming you are going for Precision Aerobatics (stunt), you can use your RC engine with the throttle wired open. You may want to eventually switch to a venturi for optimum performance.
You don't need a 4-2 break. Many fly steady RPM with a large diameter/low pitch prop.
Good luck whichever way you go, and welcome (back) to CL flying.

George

On profile airplanes just wiring the carb open may be as good or better than having a venturi made due to the tank location. One of the best running os 40 fp's that I have seen on a profile just had it's RC carb wired open.

I'll second that for a profile. The needle valve on an RC carb is generally a lot higher than a CL needle valve which means it's then closer to the centre line of a strap on tank. Another advantage is that the usual RC carb is way too big even when used for RC at the revs normally turned so you can fiddle with the idle stop screw to set the barrel opening to get the best compromise between power and fuel draw.

I'm running a box-stock (formerly a diesel, but we won't go into that) Tower 40, on an overweight profile. It does have a CL venturi. Turning an 11 x 5 APC around 9,500, 10%nitro, it is running 5 sec laps on 64 ft lines and serving very well in a 2-cycle all the way. The K&B 4011 is a favorite engine and I am building an airplane for one as we speak. It is a little bit more powerful than the Tower, I think.

Jim

Jim:

I dearly love the K&B 4011 engines. And it makes a good c/l engine.

But if you want more power get the 8350 version with the Perry carb. Most obvious fifference is the smaller front bearing. Or if yu want a screamer get the 8360, with the built-in pump and the BIG Perry carb.

Yes, I'm a K&B nut.

Bill.

The K&B .40 model 4055 ain't bad either. It is a purpose built stunt ABC version available from Brodak a few years ago.

George

Harry Higley has some nice NVA's. You should give them a look. I run their stuff in my older Fox 35 and 36 engines. They are a great source for those elusive needle valves that we seem break so often.

What? K&B engines? ME?

Haw.

Wow, looks like they're ready for the smelting pile.

Use throttle on your next CL plane....!

Contact me for information reqarding electronic controls, fly with 2 lines, and have up to 6 functions on board using servos which can include throttle control and more.

Windy Urtnowski has a system that does not require insulated lines, I can tell you about and how obtain (I don't sell the hardware) systems that require insulated lines.

[email protected]

Clean:

I was thinking about melting some Fox "Engines" down to make some more K&Bs, but the metal in the Foxes wasn't good enough.

Haw.

Bill.

Oh now that IS blasphemie!

HEHE

Teacher: Johnny, how was iron discovered?

Johnny: I'm not sure...but I heard they smelt it.



George

If you plan on having an RC engine converted for CL be very careful on who you send it to. I sent one to a well known engine person over a year ago and I do not know if I will ever see it again.

There never were a great many engine models that performed the "Classic Stunt" type of run, usually referred to as the "4-2-4". There always were a few stunt pilots choosing other engines instead, and doing well enough.

Thus, there ahould be no need to "send away" most engines to have anything done to them. Just buy the right size intake venturi fitting, and a good NVA, install them, and go flying! If you want a 4-2-4, buy the right engine in the first place, otherwise run it just the way it was designed. The classic run is rapidly losing favor the last few years. It's somewhat cyclical, so now that the Brodak 40 is out, maybe it will go the other way for awhile.


Kiwi

**

I still like the sound of my Fox 35 going over the top to inverted.

Bwaaaa
Bweee
Burppp

Blubber
Blubber
Bwaaaa

Clean WC:

Let's translate the sounds:

Bwaaaa - running in a four cycle, level flight.
Bweee - went to two stroke with up elevator.
Burppp - over the top, unloaded and ate its con rod.

Blubber - Since it ate it's con rod the rest of the exhaust sounds are mental imagery.
Blubber - Clean clouding up when he realizes he's blown another Fox.
Bwaaaa - And now he's really crying.

Haw. Got you!

Bill.

Danger! Will Robinson!

Warning! Warning! Fox blasphemie with C/L experts and devout fans is bad for you!

You have obviously shown your hand by not knowing about the infamous Fox burp. The Fox .35 stunt is really a fine engine when used as it was intended. Only problem is the crappy needle. And maybe the fact you can't get it out of the box in ABC form.

I can recall when I first was told that a Fox burps. It was only fifteen years ago; and prior to that point I'd already been flying Fox engines regularly for about 25-30 years. Before that, fellow CL folk I met used them almost as far back as I have memories of the hobby. I didn't immediately understand all of the pissing & moaning that was aimed at this symptom.

(After I finally looked past the homeliness of Fox products, and bought some, I bought many more. Of a minimum 12 of them I've owned, and five or six I still own, not one ever shed a con rod. " That part is bullet proof", Robbie says. George Aldrich denied ever having been aware of any such burping problem. I ran into a pronounced variety of it exactly once, personally. In the years since having first heard the "burping" complained about, I have heard Foxes do it.

And OS Maxes and McCoy red heads also. It's just part of the "normal" sound (to me) of a many old engines running a 4-2-4! Nothing to get excited about at all.)

The only Fox's sheding con rod's were custom racing versions. That's an assumption because I don't recall anyone having that problem. They don't look very good, and some of the RC versions have crappy carbs, but the rest of the engine is really very well made.