RE: Close look at GP .07 Thunder Tiger
Right on Graham, see below.
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GP .07
Specification:
Displacement: 1.13 cc. / 0.069 cu. in.
Bore: 12.0 mm. / 0.472 in.
Stroke: 10.0 mm. / 0.394 in.
Crankshaft: M4x0.7
Practical RPM: 3,500 ~ 24,000
Output: 0.20 BHP / 18,000 RPM
Weight: 95 g. w/muffler / 3.35 oz.
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Norvel .074
General Specs:
- 1 cylinder
- Displacement: 0.074 cubic inches
- Bore: 11.7 mm
- Stroke: 11 mm
- High RPM: 22000
- 0.380 bhp @ 22000 RPM
- Weight 2.65 oz.
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I've been able to stuff .09 parts into the MP Jets .06 and have just done the same with a Norvel .06
This makes both of them short strokes compared to the original.
With the GP 07, already a short stroke, we don't have much room to play with.
One fairly certain way to gain 1.5K, from my experience with the Brodak/CS engines, is to install an insert taking a turbo plug. Or, if you can find one, a Norvel .074 glow insert ought to do the same.
I've been told by Great Hobbies that the GP .07 is discontinued and parts will be in short supply down the road. I have a couple of rods on the way to see if they can be adapted to the Norvel .074