bobb

Hi Guys,

The fuel pump for a 72 W30 is the 70436, which has a huge body compared to the 70 W30 fuel pump (don't have the part number). The 70 W fuel pump looks just like any ordinary 455 fuel pump, but the 72 W has a much taller can. Obviously the bigger can holds more fuel......but why does the 72 pump need to hold more fuel than the 70 pump? I guess I'm just not seeing what changed in the design of the motor that caused the pump design to change. I see everyone lists the 70436 as the "high performance" fuel pump.....but why. Anybody have any thoughts?

thanks,
bob

jensenracing77

i wonder if it had something to do with the fuel filter being an in line filter going to the carb? i wouldn't think so but they did it for some reason. i would like to know also.

bobb

Hi JR,

I don't think so......but I'm not sure. Once the fuel filter is full the amount of fuel that flows to the carb doesn't change whether there is a filter in the line or not. It's like a bucket and garden hose......once you fill the bucket, the amount of water that comes out of the hose into the bucket is the same amount that's spilling over the bucket.

It seems the bigger can would allow for a longer pumping stroke, so maybe it has something to do with emissions, as all cars after 1970 had to have a vent return to the tank. I don't know.......and I'm not sure what the 71 W30 pump looked like, but I'm thinking it looked like the 70 with the smaller can. It seems everyone listes the 72 pump 70436 as a "high performance" OEM pump......I'm just not sure why.

Have a great day,
bob

jensenracing77

i know what you mean. the part that makes me wonder is the fact that you can't really have any more fuel pressure or it would push past the float valve, also couldn't be higher volume because the engine is only going to take what it wants. makes me wonder how it could be a higher performance pump. which brings up back to the question, what makes it higher performance?

72xw30

Bobb,

The part number for that pump is 40736.


Sam

bobb

Sam....you're right, of course. I've just got too many numbers in my head to get the order right too.

thanks,
bob