Control Line: Aerobatics
Wynn Paul
MUFFLER MANIA. Precision aerobatics has been leading the way in control-line in the past five years in the use of mufflers for competition. Some of us no doubt miss the classic 2-cycle break of the Fox 35, or the whine of a straight Supertigre 46, or the Offenhauser-like blast of Bill Rutherford's unmuffled Supertigre 60 at the '72 Nats.
Aside from the noise deadening qualities, the more practical side of muffler use is that of muffler pressure advantages and conformance to FAI rules. It is generally conceded that the use of a tap off the muffler directed into the tank results in steady runs throughout the pattern.
Muffler selection is more a process of "what can I find to fit?" rather than "what is the best muffler to use?" There are about 15 various types of mufflers which from time to time may or may not be available to the average stunt flier. In many cases the modeler will have to, in the words of World Champion Les McDonald, "Do some cutting and fitting to get a muffler to fit the engine and not give too much back pressure."
Two of the brightest stars in commercial mufflers recently have been the appearance of the Gene Martine "Custom Master Muffler" and of the Slim Line Muffler. Gene's muffler is being produced by his shop class and is machined from aluminum bar stock. The long part of the body has a finned matte finish. The exhaust tube opening is 5/16 inch diameter. The adapters bolt onto the engine with two bolts. The muffler for the Max 35 or Fox 35 weighs about 36.1 grams (about 1.25 oz.) and the ST 46 size weighs about 37.28 grams. The muffler is delivered with a pressure fitting hole tapped into the case. Tests by Californian Tom Lay showed a drop in rpm of only 250 when the muffler was put on a Max 35. The Custom Master Muffler sells for $15.00 plus postage and is available from Gene Martine, c/o Southside Skill Center, 2924 Knights Lane East, Jacksonville, FL 32216.
The Slim Line Muffler is also machined from aluminum bar stock and resembles an overgrown exhaust extension. Sizes will fit all popular engines. The muffler has a pressure tap hole. The weight is approximately 3/4 to 1 oz. Cost is $9.95 when found in shops. Les McDonald reports that he has recently been using one. and cannot feel much power loss. He stated that he shortens the muffler and has drilled some large holes in the end to reduce back pressure. The address of the manufacturer, if not available in shops, is Slim Line Mufflers, 8631 E. Roanoke, Scottsdale, AZ 85257.
The DuBro Universal MU 795 muffler has been used by several Nationals qualifiers on both the Max 35 and the ST 46. Bob Whitely and Rich LeRoy have utilized it with some slight cutting, drilling and fitting. The Air Foil muffler from J.C.M. Specialties in the small size (19-25 on the package) is shaped like an airfoil and will bolt right to the ST 46. Some modification is needed for the Max and Fox.
The Fox No. 90222 muffler is made for the Fox 35 and, of course, bolts right up to it. The Musumeci Connection (father and son) has been using this on its Fox after removing the inside tube, creating a large chamber. Works well and cuts the weight.
One of the most popular mufflers in the past couple of years has been the Art Adamisin creation from aluminum bar stock. However, Art injured his good hand and production has been stalled over the winter. If you want one of these excellent mufflers it would be best to write Art at 22454 Fairfax, Taylor, MI 48180. These mufflers have been used by Bob Hunt, Gene Schaffer, Les McDonald, Dave Hemstrought, Ted Fancher and Bill Fitzgerald. There is a similarity between the Adamisin muffler and the recent Gene Martine muffler. Both are excellent products.
The Semco muffler, no. 202 CL for .29-.40 engines priced at $12.95, will bolt right up to a Max and the ST 46. The weight is about two ounces with the extension. If you're looking for some nose weight you might try the standard Supertigre muffler S29B for the ST 46 which weighs about three oz. It sells for $12.95. Also, the newer type OS Max mufflers which come with the engines are good for nose weight. And, the small Tatone will help front-end stability after some cutting and hogging to fit either the Max or Fox.
In some areas the Enya M-200 muffler for the ST 46 may still be available. This is a fairly light item costing about $8.00. Bill Werwage used this for some time on his USA-1. The Murphy Maxi-muffler at $10.95 can be used if desired. It is rather large and has an asbestos-type covering which expands with higher engine rpm.
As best as the writer can find, the "MAC" and the "Silencer" mufflers are no longer being imported although they may be hiding in some hobby shops around the country. You may also be able to find one of the old-style Max mufflers which are still popular on the East coast. The writer has been using a Merco muffler since 1971 but it is difficult to obtain. It will bolt right up to the ST 46.
For those experimenting with the HP-40 engine (as have Dan Shafer, Bill Eybers, Bill Werwage) you could use the straight HP muffler which is rather big and heavy; or you could do as Dan Shafer has and cut off the HP muffler leaving some metal around the extension and then bolt on the DuBro fins to what is left. Takes a little ingenuity but works well for Dan. Bill Eybers converted an old-style Max muffler to the exhaust extension and bolted it to the HP engine.
The Bob Paul muffler has been used by both Bill Werwage and Bob Gieseke on the Fox, the Supertigre and the HP 40. However, Bob has had a series of misfortunes this past Spring including a ruined apartment from a burst water pipe and probably will not get into production until late Fall. If and when he does get back in gear his little muffler is a good one.
Two other examples of fine little homemade mufflers are the chrome-plated ones made up by Chuck DeLano of Indianapolis; Dennis Duvall is currently using one on his latest semi-scale MIG. And Bill Scott, Cincinnati, has created a unique little muffler-extension combination which is very effective when opened up by drilling out the holes in the bottom of the aluminum extension.
For what it's worth, in the writer's opinion the new Gene Martine muffler looks like the best of the lot for both performance and delivery. The machine work is beautiful, the muffler works, it is not unsightly, and Gene is aware of the supply and demand problems which have hurt some other good products. The Slim Line muffler will also catch on as it is simple, small, and available.
If you want your Max 35 engine re-worked then let the writer suggest Tom Lay regarding workmanship, service and communication. Bob Whitely, Ron Merrill, Vincent Judd and Val Britton all reported that turn-around service has been from two to three weeks—which is not bad. Tom will modify piston, head, venturi, needle valve, hand-lap piston and sleeve, and precision assemble your engine. Cost is $10.00 plus postage, and plus any new parts required.
Tom also has available T & L custom .40 stunt engine, a reworked Max 35 with displacement of .4000037 and with power similar to a Supertigre 46. The engine will drop right into the mount holes of the Max 35 and will make an overweight 35-size ship flyable. For information and prices on all of the above write Tom Lay, T & L Model Specialties, PO Box 6052, Torrance, CA 90504.
For information on stunt or PAMPA write the author.
Wynn Paul, 1640 Maywick Dr., Lexington, KY 40504.
Transcribed from original scans by AI. Minor OCR errors may remain.
