Gyro Pull Testing

The amount of thrust that a engine/prop combination provides on any given gyro is a topic of intense interest within the gyro community. To resolve these questions, a simple if relatively unscientific solution has been found.

Gyros are attached to a commercial type scale that gauges the amount of pull in pounds. The pilot straps in, fires up and applies full power to the gyro and the scale is read. Here are some of the recent pull tests from Bensen Days 2005. More test results will be given when available.

Bensen Days 2005 Results

Dominator / Rotax 582 Owner: Scott Lewis Engine: Rotax 582 65 HP Prop: RPM: Pull: 340 lbs

RAF-2000 / Subaru EJ-22 Owner: Rudy Graffeo Engine: Subaru EJ-22 Prop: 68" 3-bladed warp with 13 degrees pitch RPM: 5260 Pull: 490 lbs (the pull-meister at Bensen Days 2005)

Butterfly / Rotax 582 Owner: Chris Wilson Engine: Rotax 582 Prop: RPM: Pull: 320 lbs

Gyrobee / Rotax 447

Owner: Rick Martin
Engine: Rotax 447
Prop: 3-bladed IVO
RPM: 6250
Pull: 260

Dominator / HKS-700E Owner: Carl Schnieder Engine: HKS-700E 60 HP Prop: RPM: Pull: 275 lbs

Dominator / Rotax 582 Owner: Ron Awad Engine: Rotax 582 65 HP C-box 2.62-1 reduction Prop: 60" 3-blade warp RPM: 6430 Pull: 350 lbs

Bensen B8MG / McCullough 90 HP Owner: Mike Gaspard Engine: McCullough 90 hp w/ Holley 1940 carb and A.R.D. CDI conversion Prop: 52" diameter x 26" pitch Tennessee Prop. RPM: 3250 Pull: 300 lbs Max RPM level flight - 3600 RPM. Empty weight 302 lbs.

More results to follow.