dj55b

iTrader: (2)

Electric Fuel pump VS mechanical fuel Pump

Browing through the web I saw that xtreme rotaries were offering kits to adapt the Aeromotive mechanical fuel pump. Now i thought that mechanical fuel pumps were kind of history .. but knowing extremerotaries ... they tend to use only the best .. so I was woundering what the advantage of a mechanical pump is over an electrics one.





Thanks in advance.

dj55b

iTrader: (2)

Just for the fun of it ... Need fuel anyone ... umm 6 injectors ...

Rx-7Doctor

iTrader: (13)

Mechanical fuel pumps are a thing of the past for todays fuel injected cars. But are still widely used on most carb'd applications. The advantage is that you can't blow a fuse because there is none. You don't have to worry if your charging system has just failed because the fuel pump will still work. It has just a lever and a diaphram as moving parts, so not much to wear out. And generally fuel pressure is maintained at all times without a regulator. But the down side is they are only good for carb'd applications.
What are they driving the pump off of?

dj55b

iTrader: (2)

Alright so it can't be used on FI ... they don't have geared pumps to push the pressure?
I would assume they would run it off the main pully

85rotarypower

There are mechanical fuel pumps that push enough pressure for injection. Just look at a diesel injection pump. Not only do those provide proper distribution of the fuel to each injector, but they also provide the pressure for the injection system, which is somewhere in the region of 2000psi I think. I could be wrong on the pressure though, but I know its a lot.

Hyper4mance2k

iTrader: (40)

http://store.summitracing.com/partde...5&autoview=sku
Pressure Range (psi): 2-200

dj55b

iTrader: (2)

I guess I should of looked that up before asking that stupid question ...

Wouldn't this unit be lighter and more reliable than Electrics pumps?

The one question that I have concerning this is how does it start the engine at low rpm ... I would assume that that it would be fairly low pressure down there? so would you need to install maybe a faster starter?

I think this may be one of the items on my to buy list

Weed Wacker

the advantages that i see for the electric pump versus a mechanical one is that the electric pump can still be mounted where the factory one is. I have a holley blue and i used the one stock "stud" with the 10mm nut on it and then drilled a hole in the floor in order to mount the other side with a thru-bolt.

Also, even though it may draw more power from the charging system, the alternator is still dragging on the engine the same amount as usual, with a mechanical pump your adding to the parasitic drag on the motor. The whole reason that they make electronic water pumps and such is to cut down on this, you would be going in the opposite direction by using a mechanical fuel pump.

I know someone with a mechanical fuel pump on a old camaro with a carbed 396 in it and he is still using the original starter but im pretty sure it had a mechanical fuel pump originally.

I think that the stock starter spins fast enough though that it wouldnt be an issue, but i could be wrong as i havent ever seen one on a rotary before

680RWHP12A

mechanical pumps like the one pictured are generally used in extreme hp applications (2,000 hp range and up)where most of the electric pumps cant hang.however, there are a couple good electric pumps out there now that can hang in semi high hp conditions(2,000 and down) like product engineering, weldon, BG, aremotive, but those still require maitinence, and 16 volts for best performance.... mechanical pumps like the one pictured have internal bypass regulator as well as an additional external unit... another plus side to the mechanical pump isits mechanical, thus a voltage loss during a run will not affect it saving you from a motor meltdown ..
the downside to mechanical fuel pumps is they are a bitch to prime and if you suck it dry( like when you pull the parachute at the end of the run) you have to spend another 15 minutes to get it primed again.. these pumps are in no way "streetable" and are for drag racing only...

dj55b

iTrader: (2)

huh ... i find it odd that on the summit racing site in the little blog at the end it says that these pumps don't require priming ...

680RWHP12A

here is a link to the installation instructions from the pump mfg...trust me its a bitch priming mechanical pumps of this nature

http://www.aeromotiveinc.com/pdf/17140.pdf