Fuel pump question
#1
Fuel pump question
I have a 1969 442 big block with air conditioning. I ordered a new mechanical fuel pump and it is much taller than the original. Which is correct for my application (taller or shorter)?
Thanks in advance!
Thanks in advance!
#6
#10
#11
Don't assume anything you read in the RockAuto online catalog is correct. Determine the correct P/N independently, then order by P/N on RA.
#13
I have no idea what your problem is.
The OP said that RA didn't list that P/N for a 400. I said that RA is frequently incorrect. Your P/N is the correct one, and if the OP simply searches on that P/N instead of searching by application, he'll get the right part.
Chill out, dude. Not everything is about you. Unless you have an ownership position in RockAuto, this has nothing to do with you.
The OP said that RA didn't list that P/N for a 400. I said that RA is frequently incorrect. Your P/N is the correct one, and if the OP simply searches on that P/N instead of searching by application, he'll get the right part.
Chill out, dude. Not everything is about you. Unless you have an ownership position in RockAuto, this has nothing to do with you.
#14
I have no idea what your problem is.
The OP said that RA didn't list that P/N for a 400. I said that RA is frequently incorrect. Your P/N is the correct one, and if the OP simply searches on that P/N instead of searching by application, he'll get the right part.
Chill out, dude. Not everything is about you. Unless you have an ownership position in RockAuto, this has nothing to do with you.
The OP said that RA didn't list that P/N for a 400. I said that RA is frequently incorrect. Your P/N is the correct one, and if the OP simply searches on that P/N instead of searching by application, he'll get the right part.
Chill out, dude. Not everything is about you. Unless you have an ownership position in RockAuto, this has nothing to do with you.
There's no need to say "chill out" or "not everything is about you" for all to read
Like i said i will not post anymore
Last edited by JOHNNYOLDS442; September 3rd, 2020 at 11:13 AM.
#16
#17
Do you have a reference for that info? Airtex says that both their short Olds pump (41567) and their tall pump (40736) are the same 40 GPH at 1800 RPM. Both are listed as 6.5 psi.
#18
No, I don’t have any documentation, I based my reply on a verbal discussion with Airtex on the exact part numbers you mention. Way back when I was planning a fuel pump swap to fit the Edelbrock heads I called Airtex. The man I spoke to said the large canister pumps were considered high volume.
I assume there has to be a reason for the large canister. And based on personal experience, I can say the 40736 pump is enough to keep up with the fuel needs of low 12 second 66 cutlass.
#19
No, I don’t have any documentation, I based my reply on a verbal discussion with Airtex on the exact part numbers you mention. Way back when I was planning a fuel pump swap to fit the Edelbrock heads I called Airtex. The man I spoke to said the large canister pumps were considered high volume.
I assume there has to be a reason for the large canister. And based on personal experience, I can say the 40736 pump is enough to keep up with the fuel needs of low 12 second 66 cutlass.
I assume there has to be a reason for the large canister. And based on personal experience, I can say the 40736 pump is enough to keep up with the fuel needs of low 12 second 66 cutlass.
#20
My other thought is maybe the larger canister is a like a storage “tank”, which I guess technically wouldn’t make it high volume as much as a reserve. I’m guessing you could fill the float bowl of a Q-Jet 2 or 3 times with the fuel contents of the canister.
Or, as you suggested, the larger pump has a longer stroke on the diaphragm. Or a combination of both? All I can say with any certainty is the 40736 pump does supply more fuel based on my experience with the 66 Olds. I was pretty impressed for a $40 pump from Advance auto
Or, as you suggested, the larger pump has a longer stroke on the diaphragm. Or a combination of both? All I can say with any certainty is the 40736 pump does supply more fuel based on my experience with the 66 Olds. I was pretty impressed for a $40 pump from Advance auto
#21
The larger canister may help with hiccups from the tank, like a surge tank, but only the diaphragm motion fills the bowl. Now I'm really curious. I could see where the taller canister would allow for more diaphragm travel, but you can only flex that rubber so far, and the diaphragm diameter is the same in both. The other problem is that a reservoir of fuel next to the engine like that would seem to heat up, potentially causing percolation.
#22
This is from the 1971 EAM:
They're calling it a "surge dome". Could it be that the larger dome aids the flow via smoothing out the surging fuel?
They're calling it a "surge dome". Could it be that the larger dome aids the flow via smoothing out the surging fuel?
Last edited by Rocketguy; September 4th, 2020 at 05:47 AM.
#23
Ok, let’s settle this. Who has one of the large canister style pumps sitting around unused, willing to undergo a autopsy? The only one I have is currently in use on Dads 455 powered GMC truck.
#24
Since the pump was over 20 years old and i wasnt sure of its application, i busted her open for your review. Im not sure what i am looking at. Maybe the CO community can use this info.
#25
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May 18th, 2020 07:22 PM