EFI and Electric Fuel Pumps... - Lateral-g Forums

Derek69SS · #1 06-07-2005, 08:58 PM

Teach me all I need to know, experienced ones.

I'm putting a stock (for now

) '95 LT1 in my '69 Chevelle. I was told to run an in-tank pump rather than an in-line. Why? I don't know... something about heat and reliability.

I've got a new tank that I can weld on if I have to. It's new, so I won't explode myself.

<--I like this little guy, I use him somewhere in all my posts...

What do you guys recommend I do? jimmy-rig the stock caprice pump into the chevelle tank? Got any ideas that are cheap and easy? Emphasis on CHEAP... and EASY... don't forget EFFECTIVE

I don't want to constantly have to haul a cooler of ice in my trunk with my fuel line coiled inside

LVCamaro · #2 06-07-2005, 09:14 PM

If I were you I'd throw that in-tank pump as far as you can throw it. Jody and Scott would be glad to help you dispose of it after what they've been thru with the Chevelle on HRPT. The in-tank theory sounds good on paper, but I've given up on depending on them in real time.

SS

Musclerodz · #3 06-07-2005, 09:35 PM

The question is, why do they work so well in hundreds of thousands of production cars, but we can't get them to work in our Hot Rods? Routing too close to exhaust? Running too small of a pump requiring to work extra hard? Installing too small of a fuel line so the flow isn't correct?

Mike

69MyWay · #4 06-08-2005, 07:41 AM

I would suggest installing a complete gas tank from a 1988-1996 Caprice in the car. The fuel inlet will go behind the license plate. There will be some minor mods but it will go.

I was able to squeeze a plastic tank from a 1996 Caprice in my 69 Camaro with some mods to the tank and to the trunk. Your car is much larger so you should do great. The older caprice tanks are metal with the intank pump.

They have great baffles that prevent fuel starve in corners.

You can then run a stock replacement pump.

If you cut your trunk and make and access door you will be able to service the pump without dropping the tank.

I was able to run a Walbro High end pump that dropped in the stock housing to feed the higher pressure demanded by modified LS1 engine.

Give this a shot!

Derek69SS · #5 06-08-2005, 07:21 PM

I think I'll look for an 80s caprice metal tank to try. I did a little measuring on the plastic tank of a '92 caprice I parted out, and it would hang below the bumper in plain sight.

**Rybar** · #6 06-09-2005, 12:06 AM

You can try this install with your Chevelle tank:

http://www.thedetailzone.com/Tanks%2...%20Install.htm

69MyWay · #7 06-09-2005, 04:01 AM

It does hang down, but I think it looks kind of cool there.

I like what Rybar just posted though very much. Nice way of doing it all in one. I am running that 255 pump in my car.

RickWI · #8 06-09-2005, 11:30 PM

The problem, as was encountered on Power Tour this year, were the very high temps, espcially through Dubuque stop and go traffic combined with very high underhood temps and return lines located in engine compartments. This is compounded by many of us running pumps that need to supply enough fuel to support 700-900 HP at full throttle but at idle we are utilizing only 1/100th of that capacity. Therefore all that heat that gets picked up by the return line is transfered to the fuel. at a rate of about 100 gallons or more per hour. On this leg of the tour I had underhood temps exceeding 150-160 degrees based on my intake air temp sensor. After time that heat from the returning fuel builds up in the tank to the point you can't even touch the bottom of the tank. On top of this the trunk is packed full of suitcases, coolers, booze, tools and everything else under the sun, compounding the problem even further. The end result is it starts taking out the pump.

The ultimate solution is to plumb a "returnless" style system as Mopar and other do. The return is kept back at the tank with the regulator located there as well. This greatly reduces/eliminates the hot tank syndrome that plauged many of us on this year's Power Tour.

Also, another excellent pump is the Bosh 0-580-254-044. Extremely quiet, reliable and run by the IRL boys.

Actually, for Jody et. al., for that pump to survive like it did is amazing. As far as I know, through Nashville, the pump was still going strong after they sorted the situation out. The pump was never the problem. The environment it had to live in though was brutal.

If at all possible you will want the pump inside the tank. 99.9% of the time it will stay cooler and also will be nice and quiet.

Blown353 · #9 06-10-2005, 03:09 PM

Rick, I don't think the problem so much is the heat taking out the pump, but the temp of the fuel exceeding its boiling point; thus, you boil the fuel and get vapor lock. Fuel pumps can't pump vapor, and when they start pumping boiling fuel the pump cavitates, which is what ends up destroys the pump as all the internals basically get "rattled" to death.

With some of the newer emissions formulations for gasoline (oxygenated especially), fuel boiling points can be as low as 135-140ºF. Considering your engine is probably at 180-200F, and you're pushing a lot of fuel volume, it doesn't take long to heat soak the fuel when there's not a steady stream of cool air over the gas tank to cool it as it would be when you're driving down the freeway.

Another solution is a fuel cooler. Just run the return line from the regulator though a cooler mounted on the front of the car (or hidden out of sight with a fan). This is also a good solution, but it makes me a bit nervous as it creates yet another potential leak spot. Luckily the return line is low pressure so if a leak develops at the cooler it should only be a dribble, rather than a spray as it would be on the high pressure side.

Troy

pushrod243 · #10 06-10-2005, 07:57 PM

Add my Car to the list of efi cars on the side of the road on the power tour. After 20 mins we were off and running. I have to find a fix yet. I was still trying to figure out exatly what was up. I wasnt sure if the return was to small since I am running a a1000 Aeromotive pump and a stock Ramjet 502 regulator. Aeromotive suggests running thier regulator back at the tank and deadhead the fuel rail. I wasnt too crazy about that so i tried the stock reg setup first which has performed fine until it got hot outside. I guess its time to spring for a tank and stick the pump inside it.