Total Propellant Weight: 489.7 grams 1.0774 lb
Burn Time: 1.3 seconds
Grain Geometery: (4) grains 2.75"x1.5"
Total Impulse: 137.68 pounds
Isp: 128.1
Maximum Thrust: 289.55 pounds
Maximum Chamber Pressure Estimate: 1,400 psi
Here is the thrust time curve for the test.
For this test I cut the grains to 2.75" and used four grains rather than two 5.5" grains. It should have lowered maximum chamber pressure some, and given a flater thrust profile. For comparison, look at ST-27 you will notice this burn was slightly regressive, as opposed to ST-27 which was slightly progressive. This was a slightly faster burn, with a little more propellant so the maximum chamber pressure and thrust were higher, but the curve is better. I suppose I should load the motor with the 4 grain configuration all the time.
Overall, the T-4 performed as expected. There was no blow by at the nozzle, or any damage to the motor at all.