AndyW
Posts: 1918
Joined: 1/17/2003
From: Timmins, ON, CANADA
Status: offline
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quote:
ORIGINAL: KidEpoxy
Car motors?
Every time I look at car engine, I see a giant heat sink that needs some hacksaw attention, and a micro-stub of a front case that wont let a prop clear the carb... because they stick that carb out plenty far over where they expect just a pinion gear/clutch.
.... and what kind of prop are we gonna run on a 35k .074 engine? That sounds sooooo not MAS 6x3.
I just dont get why TT did it.
Norvel made an 074 with the power of a .10
and now we hear that TT made an 074 with the power of an 049
I too wonder why TT did it but so did Cox. No slouch to well made, light and powerful engines and nearly the only game in town at the time, Cox came out with their Queen Bee .074 and like the TT, this one had the weight of their .09 but the power, barely over their TD .049,, or thereabouts. When I got my QB I had never been so disappointed in an engine before.
And yes, about car engines. Enya made an .11 for cars many years ago. Cars don't worry as much about weight and on top of that, Enyas have a rep for being built solid. So Enya made an aircraft version of their 11CX. It was powerful but also heavy. In the end, Norvel came out with their .15 and it was no heavier than Enya's .11CX. To be fair, the Norvel was plain bushed and the Enya had ball bearings but still. There's no substitute for cubes and if one had the druthers, the .15 slugging a bigger, more efficient prop wins hands down in the thrust department.
I think the answer to utilizing the punch of a car engine is to take the running innards and build a new case and Norvel like muffler along with a simpler, adjustable airbleed carb.
There have been a number of examples where a manufacturer would take their .40 and bore and stroke it into a .46 or even a .50 and give you significantly more power along with LESS weight in some cases. I managed to stuff the guts of a Wasp .09 into an MP Jets .06 and the results were good. That one too weighed less than the original because originally, that engine came with a steel liner AND piston. But the MP Jets was first conceived as a diesel and built much more robustly than needed when it was also offered as a glow engine. To take advantage of the Norvel's inherently lighter weight, I've just nearly completed stuffing the Wasp .09 bits into an .049 crankcase. Not to worry, an .06 crank was used and we have about an .072 with the weight only fractionally increased. I won't know if that did any good as we have to wait for the spring to do any running.
Mr Cox,
Here's what can be done with a plain bearinged, sport engine with muffler and good throttling using 25% fuel and a 6 X 3 prop. http://ca.youtube.com/watch?v=REkhQTmh0Gs&feature=related Top end, 19.9K and nothing fancy here, except for anodizing the piston. That may or may not have given us the extra thousand RPM over the Revlite version. http://ca.youtube.com/watch?v=XYITm-hTggM which delivers a respectable, 18.8K
The first has the innards of a Wasp .06 installed but using an early, AAN Norvel piston. The second has Revlite .06 components. The very same engine and prop and fuel is used in both videos with the exception of the difference in internals. The bonus is that both modified versions weigh less because the original had, like the Jets, a steel liner and piston.
There was talk for a while about a Norvel .02 and I would have loved to see that. However, a bored and stroked .074 up to a .10 would really have been something. And yes, I'm working on that.
< Message edited by 1705493-AndyW -- 12/25/2007 7:08:57 AM >
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Andy Woitowicz
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All Forums >> RC Airplanes >> "1/2 A" & "1/8 A" airplanes >> RE: Close look at GP .07 Thunder Tiger 
RE: Close look at GP .07 Thunder Tiger - 
RE: Close look at GP .07 Thunder Tiger - 
We know it can be done , a tweak here, a grind there. Charge!!!!!!!!!!!! Joe would probably do it but he is going to be busy building me a P-40. 