Big Barry,

Yeah, it's quite a mess at first.

I recommend you invest in MotoCalc8...

You can pick the motor (or add one based on it's ratings), select a prop or range of props, battery, esc, etc and even put in information about your airframe and it will do a pretty amazing job at telling you where you'll be at.

Without the calc, start with watts. For good 3D performance you want a good bit over 100 watts per lb. 150 is really a good starting point and quite doable.

A 16 oz plane is.... well.. one pound... so you want to shoot for 150+ watts... but you have to find a motor that will put that out at 10 volt (about what a fully charged 3 cell lipoly drops to under current draw within it's limits... higher than that and it will drop even lower as well as potentially damage you lipolies.

One motor that will do very well is the Hacker A20-22L (I would think you could use your same ESC with it as the Hacker ESC is 20 amp as well)... fairly lightweight at 2.1 oz and powerful. It will draw about 18 amps at full throttle and a 10x4.7 prop. Your abttery plays a part in this as again, some will drop more than others when being drawn from... the higher the draw, the lower the voltage... the lower the voltage, the less RPM.

If your 1320's are the Gen 1 pack, then they are good for 10-12C... or 13.2 to 15.9 amps... but we're drawing 18... we'll we're pushing the pack anyway. As hopefully you stay less than full throttle most the time and only burst for less than 15 seconds at full. The newer 1320's are rated at 15c or 19.8 amps... perfect for this setup.

Wecalced the Park 450 Outrunner and it too should do about the same. It will draw upwards of 17-18 amp with a 12x6... and that may be your problem... try a 12x6 prop. Another issue might be the packs... they may indeed be somewhat damaged and dropping significantly under draw.

The Hacker measures out to 160 watts on my wattmeter... or 160 watts per lb. Very nice. But then again, so should that 450.

Another motor I am picking up tomorrow is the HiMax 2816-0890... it too calcs out to 150+ watts with a 12x6 on 3cell. It weighs about .6 oz heavier than the Hacker and runs about the same price... $70 or so. Why would I try it? Because I want to compare them and what MotoCalc says.

HiMax motor manuals offer some real good info... see the attached. You scan across the bottom till you find the voltage you put out (10 with 3 cell) and go up till you cross the dotted lines that represent the props sizes. Then stop at the one that crosses the 10 volt line last. In this case it's the 11x4.7 at about 15.3 amps.

Watts is calculated by multiplying volts and amps 10 volts time 15.3amps = 153 watts... very good for a 1lb plane.

If you had a What's up wattmeter [link=http://www.rc-electronics-usa.com/ammeters/dc-amp-meter.html]FOUND HERE[/link] you can hook it up inline between the ESC and battery and it will tell you what amps you are drawing at full throttle and what the voltage drops to, and then it does theclac for you and tells you the watts. This will tell you if your battery or something else is awry.

If nothing else, the $60 for the wattmeter will save you money in batteries and make you better informed as to what prop to use to get the most amps within the motors/batteries capabilites to produce the best watts at 10volts. Remeber, the motors above are 200 watt motors but are putting out 150-160 watts but usually require 4 cells and a smaller prop to generate that... say 14 volts on the chart and a 9x4.7 will draw about 15 amp and give you 210 watts.

But then your weight goes up by one cell and prop goes down a good bit... so 3cell is the sweet spot for most of the smaller 3D planes.

Interestingly, look at the chart on 2 cells or 7 volt... take it up to a 12x6 prop at about 15.75 amps you get about 105 watts... nice for sport flying and can hover a little at first. You dropped one cell, lost only 1/10 of your weight but lost about 1/3 watts. There are a few motors out there that are optimized for 2 cells but it really takes a pefect setup to enjoy them... the Little Screamer Purple Peril comes to mind.

Anywho... information overload.

In closing... your 450 SHOULD fly that 1 lb plane very well... btu if the batteries are weak they may be the limiting factor and cheat the 400 and 450 similarly. Again if you had a wattmeter, you'd know... and you could swap the battery out with nother and see what it's voltage dropped to...

hope this helps some.