<![if !vml]> <![endif]> By Ken Burdick
Yes Folks, itÕs true.
Here is your turn-key guide to the NorthwestÕs B Proto Speed event. Admit it -- youÕve always liked those cool-looking speed planes, but the guys were so secretive, you never really got much in the way of what to do. Well fellow geezers, worry no more. This will tell you all you need to know to enter and do well in this fun event.
LetÕs review the basics. ItÕs a bit like golf in that ther are challenges for ANY skill level.
<![if !supportLists]>1. <![endif]>Engine: OS LA .25. No longer manufactured but very plentiful on ebay or on engine classified ads. It should take less than 1 hour of looking to find one .
<![if !supportLists]>2. <![endif]>Airplane kits available are:
Partner Products. Partner offers two models, Smokey Joe and the Blondie kit. There are basic kits and Pro kits that include all items needed except wheels and bellcrank. The prices begin at $50.00 and are well worth the extra cost for the Pro version.
Pat King has recently released a very nice Goodyear kit that meets all requirements for the event. it too includes about everything needed except wheels, tank and bellcrank. The Goodyear kit sells for $105.00, here is what Pat had to add about the kit.
The kit contains all the laser cut parts, the stick wood, the partially machined leading edge, Aluminum for the landing gear, M4 screws and nuts for axles, 4-40 button head socket cap screws for gear, 6-32 button head and blind nut for bellcrank mounting, 3/32 music wire for the skid, 1/16 music wire for the elevator joiner, and the nylon tip skid for the leadout guide. The kit does not contain the bellcrank, pushrod, or control horn. The kits sell for $105.00 plus postage from ZIP 60449.
Pat has just recently made a simple B Proto kit, it sells for $53.00 and should work every bit as well as the higher price spreads.
3. Brodak Manufacturing
Strange as it seems, Brodak offers the least expensive alternative in a kit. They offer two Goodyear kits that are large enough for the event, and both under $50.00. This is a bare bones option so unlike the Partner kits will need additional items but should work every bit as well if built properly.
-- For solid lines, I suggest MBS firstname.lastname@example.org
-- Props, APC 7x7 sport prop.
-- Spinner. 1-½” plastic, or find a Froom or Veco on E bay.
5. Engine modifications.
We won’t worry much about this for the beginner, but here are a few things to get you into the mid 90s to 100 mph range.
Remove the stock venturi, remove the muffler, run a pressure tank (either bladder or tin pressure tank). Buy a spare head from Tower Hobbies and have it machined to .010 clearance from the piston at top dead center. If this is too difficult, remove the head shim and lap the head to the liner, run it without the head shim.
This is my choice for the most economical way to get into the event. Find some plans or draw your own. My suggestion would be to make it in a profile orientation or upright. Avoid the inverted engine as the lower cg of rotation can and will give you “interesting” takeoffs.
Half of the fun is in doing it yourself so have at it, use light wood and enjoy the process.
The rules are simple and explained here on Flying Lines.
So there ya have it, lil geezer, you can buy a kit or roll your own. Hook up lines and fly speed.
All of the kits will work well, the one with most usage would be the Partner Products models. Partner can build it for either two-line or monoline. If you choose monoline, he can also provide the torque unit as well. Another excellent source for torque units, speed bellcranks, tanks and engine modifications is “The Fast Hippie” Marty Higgs.
Feel free to contact me if you have any question regarding your project.
This page was upated Jan. 5, 2017