Brodak's is now offering Smoothie and Thunderbird stunters. Nearly fifty years ago they were typically powered by - - - what? and good ones weighed - - - what? Conventional wisdom suggests that a Fox .35 typically dragged those around. These were almost guaranteed to have been unmuffled. We now muffle our engines. I'm trying to get a picture in my head as to what current muffled engines are usable in these two airplanes. I'm pretty sure I'd be disappointed if I bolted in a muffled Fox .35, as I guess that muffling one of these adds weight and reduces power. The extent of that and the implications of that I do not know. Any comment discussion from the group? Many thanks.
Power for 'vintage' stunters - discussion
Stuka Stunt Main Forum · 8 of 8 known posts recovered
Steve Helmick · Mar 11, 2001 09:36 PM
#1 sourceLAST EDITED ON Mar-11-01 AT 09:37 PM (EST)
Danny Dirt has been flying a series of very light scratch-built Smoothies for quite a few years, with Fox .35/tongue muffler. He admits that the light weight is key, and I suspect his Fox is as strong as any (Russian ABC piston/cylinder). I think the T-Birds would be perfect with a Tower .40/Mac's Muffler, or a Stuka Stunt FP .35 or T.40. Check the Mac's Muffler thread for details. There are also light .40's to .51's available from Double Star and Stalker, if you want a 4-2-4 powerplant. Also, since both are upright engines, you might consider the PAW .35 diesel. Steve
I'm flying a T-Bird II that is almost 50 ounces with a stock fox 35, and it flies pretty well. Another choice, altough not currently produced, is the OS 35-S. Currell
Old Sourdough · Mar 14, 2001 12:48 PM
#7 sourceAnother fairly available loop scavenged option would be the Max-H .40.
OS
LAST EDITED ON Mar-12-01 AT 02:08 AM (EST)
The Smoothie is smaller than many flapped oldies and even the kit versions seemed to build relatively lightly. But they had some unusual flying characteristics when slowed down. The tails are pretty "short" for coupled flaps, which makes exits difficult (you get unwanted "bounce").
I've seen them flown with half a dozen kinds of pre-1960 engines; Fox 29's, Torp 29's, and Veco 29's all worked well enough with the plane when it wasn't overweight. A Fox 35 would be more than merely adequate, even with a muffler, in my opinion.
However, the Thunderbird could easily build too big and heavy for anything but the most exemplary of 35's. The first two versions had 590 square inches of wing, which went up on a later one to a claimed "610." With the semi-elliptical style tips, it will be hard to check that claim. Palmer used the Series 100 Veco 35's in his, and flew them somewhat faster than Aldrich flew Noblers.
That Veco, and the Merco 35 that is its virtual clone, were among the more powerful of stunt 35's available in the 1950's. Probably stronger than the OS Max-S, which was considered to have plenty of grunt, even muffled, for planes the size of the T-Bird. None of Palmer's designs pushed at the wing thickness standards the way Southwick's planes did -- a 17% airfoil for the T-Bird -- skinnier wing than that and an odd rearward thickness point on Smoothies).
The GH Torp 45 was an extremely popular engine for "big" stunt planes like the T-Bird, and like Southwick's Lark (which bears some resemblance to a T-Bird). I plan to put one of those in a Viking, which isn't nearly as big as a T-Bird, but the early stunt pilots often put 60's in their Vikings! The K&B 40 has been produced with a muffler for 25 of the 35 years it's been made, and has power to spare for a T-Bird, I'm sure, even when a muffler is attached.
(Added in edit: you would probably want to get an aftermarket muffler of some sort. The stock unit for the Torp is a large, ugly* thing that weighs close to four ounces!)
Kiwi
._.
>The Smoothie is smaller than many
>flapped oldies and even the
>kit versions seemed to build
>relatively lightly. But they
>had some unusual flying characteristics
>when slowed down. The
>tails are pretty "short" for
>coupled flaps, which makes exits
>difficult (you get unwanted "bounce").
>flapped oldies and even the
>kit versions seemed to build
>relatively lightly. But they
>had some unusual flying characteristics
>when slowed down. The
>tails are pretty "short" for
>coupled flaps, which makes exits
>difficult (you get unwanted "bounce").
Hi, Kiwi:
Have you read Bob Palmer's letter to Dan Rutherford in the March/April 2001 edition of Stunt News (page 53)?
It refers to his Smoothie, kitted by both Veco and Brodak and is worth reading.
jmh
RocketCityJim · Mar 12, 2001 07:59 AM
#4 sourcePower huh?
Let's see here; Modern Schnerle .40s' modified or not. Even the OS .35's when modified by Neumann. Also the Thunder Tiger .36's and .42's as modified by either Neumann or Smith. Even a stock one would do very well. If you could get your hands on a ST .46 that would be good too! Lot's of different choices these days! More than back in the 50's and 60's I beleive.
Rocket City Jim