Thanks guys, that cleared up a lot questions, I do use Spektrum on all my planes so will go with the 6v battery, for torque and be on the safe side.

CGR ..I will use your chart to figure out final choice of motor , ESC and battery combo. The one plane is a FW190 57" ws and had a os 40 in it. The other is 80" cub new build, so no prior setup, both should be 6-7 lb range.

This is the tenitive setup. Was planning on using for both. They have different KV rated Power 46 so input welcome.


The G46 (50-55-700) Power 46 brushless out-runner motor can replace a .46-.55 two stroke nitro engines.
It is equivalent to AXI 4120 and E-Flite Power 46. It is capable of producing up
to 9 lb of thrust and generate about 1000W of power.

Specifications:

* KV: Listed as 700, tested to be approx. 730.
* Weight: 10.6oz (300g) for motor only, not including mounting accessories.
* Motor Diameter: Approx. 50mm
* Shaft diameter: 8mm
* Max efficiency: Approx. 50A
* Max Load: Approx. 60A

Motor Dimensions:

Recommended Setup:

* 80A Opto brushless motor ESC
* 3-5S LiPO and at least 4000-5000mAh.
* Prop Selection: Remember to always use props designed for electric motors, nitro props are heavier and might overload the motor.
With 5S LiPO: 12x6, 11x5.5
With 4S LiPO: 14x6, 13x6.5
With 3S LiPO: 14x8, 13x8


Hobbywing Pentium 80A Brushless ESC

1.1 Output: Continuous 80A, Burst 100A up to 10 Secs.
1.2 Input Voltage: 2-6 cells lithium battery or 5-18 cells NiCd/NIMh battery.
1.3 BEC: None.
1.4 Max Speed: 210,000rpm for 2 Poles BLM, 70,000rpm for 6 poles BLM, 35,000rpm for 12 poles BLM.
(BLM: BrushLess Motor)
1.5 Size: 70mm (L) * 31mm (W) * 14mm (H).
1.6 Weight: 58g.


Think I will upgrade the battery

GForce 30C 5000mAh 4S 14.8V Lipo

Description

* 5000mAh Capacity
* 4S - 14.8 Volts - 30C Discharge
* 146mm X 50mm X 33mm (5.75in X 1.97in X 1.3in)
* 540 grams (19.5oz)
* Comes standard with Align/E-Flite balancing taps (JST-XH)
* Deans connector installed