I keep reading a lot about this engine aand have some questions. What venturis and needle valves are people using? What size prop? What size airplane will they power? Are there any mods that need to be done to this engine?
John:
Check out this thread:
http://www.clstunt.com/cgi-bin/dcforum/dcboard.cgi?az=read_count&om=6426&forum=DCForumID1
There was a thread by Brett Buck detailing how Phil set his up, but I cannot find it right now. I made a hard copy for the shop and set up mine identically. If you need a copy, send me your snail mail and I'll get one to you.
We use a venturi that fits an OS 32 since we had several of those around. .250-.260 w/ST style NVA. Best prop to date for us is a Bolly 3 bld 10 1/2-4 pitch. It will fly a pretty good size plane (600+ sq. in) easily. No modifications to the engine at all. High rpm, wet 2 cycle run w/tongue muffler. It has all the characteristics of a pipe motor run as to constant speed through manuevers. A little more rpm going up, and less rpm coming down (brake effect).
One of the Canadians on the board (team member ?) posted his Saturn with one and a pipe set up. Really good low cost engine.
Ours shows a good bit more power than the couple of OS 32s that we had in Aaron's Ares. I like the Aero Tiger 36 better, but the cost of the Magnum makes it attractive!
Bill <><
When the character of a man is not clear to you, look at his friends.
Japanese Proverb
I watched Mike Havely fly his Oriental with Magnum 36 at the Whirl-a-thon last weekend. He's using a tongue muffler and a Bolly 2 blade. A 12.25 x 4 or 3.75, I think. Launch rpm is arond 12,200. I don't know what venturi Mike is using (perhaps he'll respond). The engine sounds like an angry Singer sewing machine, but seemed to cut through the very turbulent wind fine and showed marked deceleration coming toward the ground. Very controllable maneuvers and consistent power.
Heck of a bargain.
Here's the set-up:
Box stock Magnum 36 XL, .257 home made venturi, ST NVA, RSM tongue muffler, Thunderbolt glow plug, 11 1/4 x 4 Bolly re-pitched to 3 1/2, 10/22 GMA powermaster fuel 12,200/12,300 RPM launch. I'm using 62 1/2 .015 lines, lap times approx. 5.0 seconds. John Leidle is using a similar set-up on a Nakke with a 10 1/2 x 4 APC prop. These things are indeed plug and play and will handle over 600 sauare inches easily.
Mike,
Man, I knew that prop size was wrong, but could remember if you'd re-pitched it. I assumed you had with that ground launch rpm.
Great running setup.