4 ms·

Yea, that and the external engine used to start the engines were pretty great ideas to simplify the project and still meet their requirements.

bombcar 3y ago
If it’s crazy and it works, it’s not crazy.
adolph 3y ago
Each of the two Buick V-8s had eight straight exhaust pipes that exited out of the bottom of the AG330. Each engine had a Hydromatic transmission with electric shift, and the two transmissions were coupled together by a 12 inch wide, toothed Gilmer belt. The pilot told the Crew Chief via intercom "Engage Buicks". The Buick operator pressed "Jet Start", and movement of the Buick throttle (one throttle lever controls both engines) downward engaged the transmissions. . . . The pilot would watch his onboard gauges to confirm minimum oil pressure, fuel pressure, and rising RPM, and then set the jet throttle to idle. At that point 30cc of TEB was injected into the burner cans, a characteristic green flame was emitted, the J58 lit off, accelerated and started to run on its own. The accelerating jet started to unload the Buicks, and when 3,200 rpm was reached, the pilot called "Buicks out", the Crew Chief signaled "cut", the Buick operator hit "Cart Shutdown", the probe fell free passively, and the cart throttle automatically returned to idle. https://www.thesr71blackbird.com/Aircraft/Engines/starting-the-sr-71-blackbirds-j58-engines-ag330-start-cart https://www.thesr71blackbird.com/Aircraft/Engines/starting-t...
lloeki 3y ago
Well, every car IC engine is started by another "engine", albeit an electric one, and these days embedded. But then again these IC engines used to be started by an external crank. So the gist of the idea is not that far fetched. (Now I'm wondering how the huge Diesel engines on massive boats are being started, I wouldn't be surprised if they were started by a smaller IC engine)
- flopsamjetsam 3y ago
  And still used by some racing cars e.g. F1 has an external (electric) starter, that the mechanic inserts into a hole in the back of the car that goes into the back of the diff -> gearbox -> ICE.
- bradfox2 3y ago
  Compressed air usually.

bombcar 3y ago

If it’s crazy and it works, it’s not crazy.

adolph 3y ago

Each of the two Buick V-8s had eight straight exhaust pipes that exited out of the bottom of the AG330. Each engine had a Hydromatic transmission with electric shift, and the two transmissions were coupled together by a 12 inch wide, toothed Gilmer belt. The pilot told the Crew Chief via intercom "Engage Buicks". The Buick operator pressed "Jet Start", and movement of the Buick throttle (one throttle lever controls both engines) downward engaged the transmissions. . . . The pilot would watch his onboard gauges to confirm minimum oil pressure, fuel pressure, and rising RPM, and then set the jet throttle to idle. At that point 30cc of TEB was injected into the burner cans, a characteristic green flame was emitted, the J58 lit off, accelerated and started to run on its own. The accelerating jet started to unload the Buicks, and when 3,200 rpm was reached, the pilot called "Buicks out", the Crew Chief signaled "cut", the Buick operator hit "Cart Shutdown", the probe fell free passively, and the cart throttle automatically returned to idle. https://www.thesr71blackbird.com/Aircraft/Engines/starting-the-sr-71-blackbirds-j58-engines-ag330-start-cart https://www.thesr71blackbird.com/Aircraft/Engines/starting-t...

lloeki 3y ago

Well, every car IC engine is started by another "engine", albeit an electric one, and these days embedded. But then again these IC engines used to be started by an external crank. So the gist of the idea is not that far fetched. (Now I'm wondering how the huge Diesel engines on massive boats are being started, I wouldn't be surprised if they were started by a smaller IC engine)

flopsamjetsam 3y ago
And still used by some racing cars e.g. F1 has an external (electric) starter, that the mechanic inserts into a hole in the back of the car that goes into the back of the diff -> gearbox -> ICE.
bradfox2 3y ago
Compressed air usually.