Decided on the Moroso accumulator in the 1.5 quart size for Ecotec setup for several reasons. The Moroso has proven to be a reliable accumulator with many race teams using them successfully for decades, both track and drag racing. The 3 quart size feeds a racing V8 that has an oil system with twice the volume requirements as an Ecotec, so I'm selecting the 1.5 quart model 23901 to install. If you watch the video from Moroso for the demonstration model 3 quart system, the test is performed using the 1/2 inch fittings filling and evacuating the sump. In the test the roughly 3 quarts of oil drains out in about 6-10 seconds (will depend upon the precharge air pressure) - through the 1/2 inch valve.
Typically a V8 motor will flow about 6-8 gallons of oil per minute. Doing the math, the return rate shown in the Moroso video aligns with those oil flow requirement. The required flow is between 24-32 quarts per minute or 1 quart per 2-3 seconds, so the 6-10 second flowback from the 3 quart demonstration accumulator is spot on. The Ecotec, requiring about 1/2 that volume of oil at about 3-4 gallons per minute or 1 quart per 4-6 seconds, aligns with these same oil flow requirements. Having that 6-10 seconds of reserve oil volume is likely very conservative and should be adequate to save an engine from oil starvation under most situations.