MotorHead

Just saw something about the Nextel cars running mechanical fuel pumps in the stock location. It looked like a ordinary fuel pump. Anyone know who makes them ?

I guess another question would be is : If they make a mechanical fuel pump that can stand up to the rigors of that kind of racing with 800HP motors why does anyone need an electric pump for a 500HP street/strip motor ?

BSeery

Those are most likely made by Holley or Barry Grant or someone like them. I am sure they are far from "stock" but they do mount in the stock location.

And yeah, they last 500 hard pounding miles, but then I am sure they get rebuilt or tossed in the trash.

I want one that will last 100,500 miles without worrying about it.

Older Than Dirt

Actually there isn't any need for electric fuel pumps, mechanicals work just fine. No need for fuel injection either, carburetor(s) work just fine. No need for fancy ignition systems either, HEI's work just fine.....and the list goes on........................

MotorHead

I think I heard Holley, I was always under the impression mechanical pumps were good to certain point then you had to go to electric pumps but these pumps work fine to 10,000RPM on 800HP motors. I have always thought mechanical pumps were adeqaute for the street and this kinda backs up what I thought.

DJ Dep

I saw that too. But if I remember right, NASCAR mandated that the new mechanical fuel pumps be relocated to the back of the car because front end impacts were causing too much leakage and fires. So the mechanical pump has been relocated to the back of the car. Electric pumps are forbidden in NASCAR for safety reasons. I'm guessing Holley probably made the pumps that were mounted to the front of the engine.

Older Than Dirt: No need for HEI....points work just fine.

Dep

Aflac

i was interested in the other one that they had shown. the one that is driven off the rear oil pump. My only question is: Wouldn't they have a problem with the car stalling if the car was running and not moving???

comp

there is a pressure reg. with a by-pass... the cable to drive the pump come's off the dry-sump pump on the "left" side of the engine, doesn't hit the wall as often

turtlevette

not to be a stickler here but what drives a mechanical pump on the rear of the car?

DJ Dep

stickler: See Aflac's post "the one that is driven off the rear oil pump."
The new one is gear-driven off the oil pump. No idea what drives the oil pump.

Dep

Russ Bellinis

The oil pump is driven by a belt. The Nascar motors are pure race motors with dry sump lubrication system. I think they have two oil pumps on a common shaft, one is the pressure pump to lubricate the engine and the other is a scavenge pump to take the oil out of the pan and put it back in the oil tank. The cable to drive the fuel pump is hooked up to the back of the oil pump drive shaft. Electric fuel pumps are banned because in a crash an electric pump could stay on feeding gasoline to a fire. By the way, the new pumps are not mandated, yet. Nascar allows teams to build their cars with the cable driven fuel pump if they chose, but they can still run the old style pump driven off the side of the engine from the cam if they want to instead.

redvetracr

they go on ebay where most used up "cup" stuff winds up. Just do a search on "Nascar fuel pump" and you will figure out who builds them or just call CV products BUT hold on!!
...redvetracr

Hitch

Also don't the oil pump's run off the rearend not the motor so the mechanical cable driven fuel pump really isn't that long of a cable...

Russ Bellinis

How long would an engine live when first started without oil pressure until the cars roll off if the oil pump was run off the rear end?

Twin_Turbo

CV products makes the mech. nascar pumps

redvetracr

NASCAR uses 5 and 6 stage pumps (I have a 4 stage in my car). The pump on the pinion is for a rear end and if two stage for the trans cooler as well.
...redvetracr

comp

a cable, like a HD speedo cable

DJ Dep

Here's the details on how the NASCAR rear-mounted fuel pump works:

http://insiderracingnews.com/info35.html

Dep

MotorHead

Yes the stock location Nascar pumps are a problem because when you hit the wall they get damaged rather easily due to their location.

My point in posting this was the perception ( on my part only ? ) that mechanical pumps fell short once you reach a certain HP but this looks like it is not the case. I know these Nascar pumps are expensive because they are billet aluminum but you could make one exaclty the same out of cheaper materials that would flow good enough for any street/strip hot rod. Now the only advantage for electric would be less HP drag on the motor but an electric setup costs much more that a mechanical pump

DJ Dep

Have you priced the NASCAR pumps? They will blow you away. It's more than just the construction of the body. They are 100% rebuildable. I think the current mechanical pump from Holley and Carter are probably adequate for any street machine except for the extremely radical ones running 2-4bbl setups or a Dominator.

Dep

Yellow73SB

They dont use electric fuel pumps becuase when you get in a crash you dont want the the fuel to keep running and feeding the fire.