BGFYankee
Tire Kicker
- Joined
- Jun 25, 2013
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I've been very interested about the topic of managing engine temperatures as of late. One of the many articles pointed out to me recently is the following by Mike Busch:
Temperature, Temperature, Temperature
In the article, Mr. Busch talks about what a rule of thumb should be for minimum fuel flow to an engine during takeoff.
"How can you tell if your full-power fuel flow is adequate? If you're limited to factory gauges, you probably can't, at least with any precision. About the best you can to is to watch your fuel flow gauge (if you have one).
A good rule of thumb is to multiply your engine's maximum rated horsepower by 0.1 to obtain the minimum required fuel flow in gallons-per-hour, or by 0.6 for pounds-per-hour. For example, if your engine is rated at 285 horsepower, your takeoff fuel flow should be at least 28.5 GPH or 171 PPH; if it's rated 310 horsepower, the minimum should be 31.0 GPH or 186 PPH. If your takeoff fuel flow is significantly less than this, have your mechanic crank it up."
This got me thinking as I feel like I've been wrestling with fuel issues recently and hoping that they are behind me. During my last flight, I reminded myself to check what kind of fuel flow I was getting on my takeoff roll. As best I could see, I am getting in the 27 gph range with mixture full forward, full throttle, and my boost pump on. I'm in a 1977 Lance with a Lycoming IO-540 rated at 300 hp. Based on the above rule of thumb, I should be seeing around 30 gph. Not a huge difference, but I'm curious if this is about what others are seeing with a similar engine? What about those with different engines? Is this rule of thumb sound?
Temperature, Temperature, Temperature
In the article, Mr. Busch talks about what a rule of thumb should be for minimum fuel flow to an engine during takeoff.
"How can you tell if your full-power fuel flow is adequate? If you're limited to factory gauges, you probably can't, at least with any precision. About the best you can to is to watch your fuel flow gauge (if you have one).
A good rule of thumb is to multiply your engine's maximum rated horsepower by 0.1 to obtain the minimum required fuel flow in gallons-per-hour, or by 0.6 for pounds-per-hour. For example, if your engine is rated at 285 horsepower, your takeoff fuel flow should be at least 28.5 GPH or 171 PPH; if it's rated 310 horsepower, the minimum should be 31.0 GPH or 186 PPH. If your takeoff fuel flow is significantly less than this, have your mechanic crank it up."
This got me thinking as I feel like I've been wrestling with fuel issues recently and hoping that they are behind me. During my last flight, I reminded myself to check what kind of fuel flow I was getting on my takeoff roll. As best I could see, I am getting in the 27 gph range with mixture full forward, full throttle, and my boost pump on. I'm in a 1977 Lance with a Lycoming IO-540 rated at 300 hp. Based on the above rule of thumb, I should be seeing around 30 gph. Not a huge difference, but I'm curious if this is about what others are seeing with a similar engine? What about those with different engines? Is this rule of thumb sound?
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