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Some of you may remember a few months ago I started a thread about using a LS1 type engine in a homebuilt airplane. Since then I've pretty well decided to do it, and am designing the fuel system.

I have a few questions about the lines and return system. I've searched and come up with little info, since this probably isn't something that directly applies to automotive use.

I plan to use 1/2 inch aluminum tube from 2 separate tanks through a fuel selector valve, through a filter, through a (probably aeromotive A1000) pump to the firewall, then use braided -8 line to the rail. There will actually be two pumps arranged with split lines and check valves for redundancy, running one at a time.

Question 1: with about a 48" unpressurized line from the tank through the selector to the pump, will 1/2" line be sufficient to avoid cavitating the pump? Would a low pressure boost pump at the tank (used for starting to push fuel to the high pressure pump) be a good idea or a waste of time and money? The high pressure pump will be about 12-18 inches higher than the tank outlet.

Question 2: can I run the return line into the feed line between the high pressure pump and the fuel selector instead of all the way to the tank? I want to avoid having to use two returns and keep the return line as short as possible since it's a pain to route it through all the structure to the wing tanks.

Any comments and suggestions will be welcome.

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smokinHawk

iTrader: (48)

#2: you should be able to run the return line almost anywhere as long as its after the pump and returns to the tank.

a guy at the shop where i get some of my machine work was telling me about some guuy wanting to put an ls1 engine in his plane for a racing aplication. looks like more people are starting to think about this.

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Thanks, SmokinHawk. To be clear in my mind, you mean the return line can start anywhere after the pump and return about anywhere before the pump? Or does the return need to go all the way to the tank? I haven't decided whether to use the "returnless" setup or not, since it appears to me to still need a return, just not all the way from the fuel rail. Am I correct that the returnless system actually regulates by haveing the regulator between the pump and fuel rail instead of after the injectors? Does that describe what you're talking about? Thanks again,

http://home.comcast.net/~ogoodwin/Mustang.html is my site that has pictures and info as well as links to a company converting LS1s for aircraft use.

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