Reply With QuoteHere's something to think about, when was the last time you read a post about a machanical pump problem.
Bill
I had a Holley blue pulling from two tanks with the outlets 12 inches higher then the pump and didn't have any problems for 28 years. I did switch to a Mallory only because the holley was to loud and it buged me. Originally posted by Craig:
blownchevy, that is what Holley says, push not pull. But, how do you build a "marine" fuel pump that has to be mounted lower then the bottom of the tank? "It has to be gravity fed" they said. The outlet on the fuel tanks are on the top on most tanks. So it will have to draw suction one way or the other in 99% of the boats out there. Teagues shop told me today to use the blue pump. The black has too much volume and pressure for something that see's any amount of extended idling. The only way they sell the black pump is with a different relief valve spring in it.
Here's something to think about, when was the last time you read a post about a machanical pump problem.
Bill
when was the last time you read a post about a machanical pump problem.[/QUOTE]
The problem with running mechanical pumps on some motors is that in the Mark V & VI BBC's case they don't have a mounting point for a mechanical pump like a Mark IV BBC so even if you wanted to run a mechanical you couldn't.
gnarley, that is it. I run a Gen 6 block with no fuel pump boss and I run a Jabsco brass seawater pump, so it's electric or buy the mercruiser seawater set up with the boss for the fuel pump. I was also hesitant to try and run almost 900 horsepower on a mechanical pump. I guess if you ran both you'd be OK though.
Craig
Craig, go get yourself an Aeromotive fuel pump,(about $260.), run all -8 lines. This type fuel doesn't "surge" like a holley and the pressure is very steady! Plumb it like this. Fuel tanks to fuel valve, in the line from the valve to the pump install a "T" fitting(this is BEFORE the pump). Then comes the pump, then the line to the pressure regulator(or the carbs, depends on your setup). After the regulator or the carbs, run the return line back to the "T" fitting. You do not need to run the return line back to the tanks. By running the line to the "T" in the main fuel line, it"s bypassing the tanks and going straight back to the pump.
On my blown Daytona 19, this is the setup I use with a filter before the pump and a filter after the pump. My pump is mounted on the top of the stringer about mid heigth on the fuel tanks. When you first install a setup like this, disconnect the return line at the "T" and "cap it off", turn on the pump and when you get fuel coming out of the return line, remove the cap and connect the return line to the "T". Very simple.
Fuel pump about $260. Fuel pressure regulator about $120.(Aeromotive also). Fuel pressure gauge can be run off of the regulator w/ 1/8 line or sending unit.
Hope this helps!
Riodog aka Michael
Thats an interesting thought there. Run basically a big recirc loop and feed the carbs off of that http://free.***boat.net/ubb/smile.gif I'm going out today to test the Holley blue pump. I made a bracket that has the pump an inch off of the bottom of the center sponson. Also put a BIG Fram water seperator/fuel filter before the pump. This thing has got to hold a quart of fuel! Figure it'll act like a surge tank. If I end up putting the old reliable red pump back on to get my butt home, I think I'll give your design a shot, as well as an Aeromotive pump! I post something later today.
Craig
[This message has been edited by Craig (edited May 19, 2002).]
I use a Mallory 110 on my 18'Crusader. It is mounted mid height with the tanks, and performs flawlessly. It is about 6 years old, and still holds consistent pressure. Look into it!
Riodog has the right idea. Spend the money and put a stout pump on it. I would even put a Magna Flow on there. It is cheap insurance
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