FREE FLIGHT OLD-TIMERS
Bill Baker — 1902 Peter Pan, Norman OK 73072
My March column resulted in some interesting mail.
Jerry Price of Walsenburg, Colorado challenged the statement I made about single‑hole needle valve bodies having the hole "looking" down the intake tube. He agreed that I related what most of the old engine instructions said, but he pointed out that the basic knowledge of venturis would tell you that the greatest acceleration of a fluid is at the point of constriction, which means that better fuel draw would be realized with the hole looking at the side of the tube.
Jerry sent me a copy of an article he wrote for the October 1994 Stunt News, the PAMPA (Precision Aerobatics Model Pilots Association) newsletter. (PAMPA is the Special Interest Group (SIG) for Control Line Precision Aerobatics fliers.) His piece presented his experiences in obtaining better engine performance at the high altitude (about 1 1/2 miles) where he flies.
His method amounts to attention to detail:
- Keep the tank close to the engine.
- Seal any leakage of air from the needle valve.
- Point the hole to the side of the tube for stronger fuel draw.
Or, better yet, he suggested going to a two‑hole system with the holes pointing to the side.
Jerry also sent me an article by Frank Williams from the March/April 1995 Stunt News, in which he set up a .60 so that he could measure 16% greater fuel draw with the hole to the side, rather than pointed down the tube. This piece explores many other variables, such as shape of the venturi, bore (size), etc.
You can obtain a back issue of either or both newsletters for $5 each plus 30% shipping and handling from:
- PAMPA Products, Box 2026, Loomis CA 95650‑2026.
For me, the most interesting thing is how other people and I have never challenged the teachings of the elders; we pass the information on to each generation without question.
Another response to my March column came from Walt Gifford (57 Fern Rd., Bridgeton NJ 08302), who noted my concern that the wrist pin could cause some damage in my K&B Sportster engine's rear exhaust configuration. He wrote that damage can happen "even with the nylon wrist pin pads" provided, and his solution is to modify the piston and wrist pin to take music‑wire clips in a way that keeps the wrist pin centered.
Walt will do this and similar small machine‑shop tasks "at reasonable rates," such as $10 for the above K&B modification. If you want his services, send him the engine or complete piston/rod/wrist pin assembly with a money order.
In a letter published in Free Flight Digest (the National Free Flight Society publication), Estes Industries made it clear that the Tee Dee .020 will no longer be produced because it is not a moneymaker for Estes (which now owns Cox engines).
The SAM (Society of Antique Modelers) engine committee has endorsed the OK .049 Cub models A and B for 1/2A Texaco Radio Control events, finding the performance similar to the Cox Texaco engine. I suggest that the .049 Cub on 30% or greater nitromethane is about the same as the Tee Dee .020, and therefore could be considered a replacement for it in such events as .020 Replica. This is based on my experience of having flown 1/2A Zeeks, Tee Dee .020 and Cub .049B.
I received a note from Greg York (6326 Corwin Rd., Waynesville OH 45068; Tel.: [513] 897‑0311) indicating that he had "32 cigar boxes of ignition engine parts," and that you are invited to send him a list of your needs and an SASE.
Jimmie Allen postal contest information can be obtained from:
- John Alling, 30188 Air Flight Dr., Valley Center CA 92082.
I have mentioned this before, but it bears repeating that you can get the P&W Old‑Timer kits via Aerodyne:
- Aerodyne, 1924 E. Edinger, Santa Ana CA 92705; Tel.: (714) 258‑0805; Fax: (714) 259‑1025.
What I did not make clear is that the kits sold under the Midway Models Co. label are also available (all of the products from the old Hobby Horn).
From sad personal experience, before you run any old engine with an integral tank, check the interior of the tank for dirt and debris!
If you are interested in receiving Stunt News (the PAMPA newsletter I mentioned previously), the address for subscriptions is:
- PAMPA, 158 Flying Cloud Isle, Foster City CA 94404.
The newsletter is $20 for second‑class mail and $35 for first‑class mail; dues expire December 31, so you might want to start with the January 1999 issue. Stunt News is an impressive publication that features an abundance of "Old‑Time Stunt" material and has quality photo reproduction.
I intend to be at the 1998 SAM Champs the week of September 14, see all of my old flying buddies, and take many photos. My main goal is to socialize. See you there!
Transcribed from original scans by AI. Minor OCR errors may remain.
