SoCal Jet Boats
Tech Talk => Engine Mechanical / Electrical => Topic started by: N2GLOCK on December 22, 2011, 09:48:34 AM
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While I have the engine out of the Rogers this winter I'm gonna switch from mechanical to electric. My plan is to get a Holley Red Marine pump and mount it in the same location as the mechanical pump via a bracket that I found thru CP Perfomance. This bracket will allow me to mount the pump directly onto the block (passenger side on a BBC where the mechanical pump would be located) I told a friend about my plan (he is very vocal) and he says that this won't work. According to him, Holley Red pumps move fuel not suck fuel and since the tanks would be sitting higher than the elctric pump, my engine would starve for fuel and I run the risk of burning the pump out. Any thoughts? He suggests mounting the pump to the inside of the transom at either the same level as or higher than the tanks. If I had the room I'd do it, but I don't.
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3 different boats... 3 different electric fuel pumps, never had a problem
1 transom mounted even with dizzy (bbc, dual side tanks)
1 transom mounted same level as (left of) center of jet pump (drive line height) (bbc, single bow tank)
1 mounted rear pass. side head. Drivers side has the coil mount. (sbc, dual side tanks)
Just a thought, on a Holley carb, I run the dual feed towords the rear of the boat, to have shorter fuel lines, no need to run the fuel all the way to the front of the motor (orig. mech. pump location)and then back up to the carb.
Thats all I got
Daniel
Mash on it
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he's right. they're pushers not suckers. ideally you want the pump as close to the tanks as possible and LOW. that way theres a siphoning like effect on the tanks and it always keeps the pump loaded.
14' to 16' from bow tank to pump, always held 6-7 p.s.i, even at 5500 rpm. All 3/8" S.S. hardline.
Daniel
Mash on it
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he's right. they're pushers not suckers. ideally you want the pump as close to the tanks as possible and LOW. that way theres a siphoning like effect on the tanks and it always keeps the pump loaded.
You have a BBC in that Tahiti right? Where is your pump?
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My water seperator is really close to and at the same height as one of my tanks. I'm thinking that there's maybe a 2' hose from the tank to the filter. The supply line from the filter to the pump is pretty long. If the Holley Red is indeed a pusher, then I wonder if it will still work ok on my application. Maybe I should ask Holley?
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A poor picture of my set-up is attached. I run a pump from each tank, each sucking through a filter/separator. There's a check valve on the outlet of each pump, prior to the tee that ties both fuel tanks together (in the supply mode only). The eliminates the need for a 3-way valve.
I like the idea of having the pumps high to PREVENT siphoning, in case one would develop a leak while I'm away from the boat.
A microswitch on the carb secondaries tiggers both pump relays so that I don't have to monitor tank levels as closely under heavy throttle.
Just an idea. Looks like lots of things will work......
Matt
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Holley's are one of the few pumps that will suck fuel. The red will support about 400hp...maybe a bit less. I've always run the Chinese eBay 110gph Holley clones in my boats and just carry a spare, because water kills them before the fail for Chinese reasons.
Mallory pumps won't self prime for shit IME, haven't used many others. If one Chinese Holley won't run it, I just use 2. A Holley type pump would work fine for your application.
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Holley blue with a regulator here....
Mounted on the bottom of the front motor mount. :thumbup:
GT
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I have used a Holley electric fuel pump to suck oil out through the dipstick before. If it will suck 12 quarts of cold 40 weight oil out through a dipstick tube I have a hard time believing that they don't suck.
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I talked to another friend last nite who races a '65 Mustang. He told me that he runs a Holley Red and it's mounted to the drivers front shock tower inside the engine compartment. He said that it's been mounted this way for years and he has never had a problem with fuel starvation or the pump burning itself out. I'm still planing on calling Holley after the holidays to see what they say. I still haven't decided if I'm gonna go for the red or the blue w/ regulator.
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While I have the engine out of the Rogers this winter I'm gonna switch from mechanical to electric. My plan is to get a Holley Red Marine pump and mount it in the same location as the mechanical pump via a bracket that I found thru CP Perfomance. This bracket will allow me to mount the pump directly onto the block (passenger side on a BBC where the mechanical pump would be located) I told a friend about my plan (he is very vocal) and he says that this won't work. According to him, Holley Red pumps move fuel not suck fuel and since the tanks would be sitting higher than the elctric pump, my engine would starve for fuel and I run the risk of burning the pump out. Any thoughts? He suggests mounting the pump to the inside of the transom at either the same level as or higher than the tanks. If I had the room I'd do it, but I don't.
Why do you want to change from a simple, reliable mechanical pump?
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Why do you want to change from a simple, reliable mechanical pump?
Hey obnoxious, good to hear from you! That's a valid question, and to be honest I don't really have a definite answer. Since I have to take the mechanical pump off to do the motor, I figured I'd just upgrade to an electric. If reliability was a concern then I'd stay with a mechanical. However, if an electric is installed correctly and if it is of good quality then I don't see why reliability would be an issue. I'm not dead set on an electric but I am leaning towards making the switch.
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Upgrade is a relative term, not to be confused with "change it cuz I want to"
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more shiney shit to tinker with. nuff said.
You nailed it right on the head!
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You'll find that manufacturers are going to recommend mounting an electric pump as close as possible to the fuel source.
Most electric pumps will not have a problem pulling enough fuel to supply a moderate big block even if the pump is not very close, because it should be receiving plenty of fuel through the siphon effect. If you start trying to run a large amount of fuel on a regular basis you might see a problem (very big inch, multi-carb, high RPM, ect...).
I do agree with Barry, that there is no good reason to replace a mechanical pump just because it's mechanical. I currently run an electric pump because the boat came with one and when it needed replaced I didn't want to have to replumb everything.