Re: Question on 67, 427/400 fuel pump hose
So-called "fuel injection hose" (SAE30R9) is for modern port EFI systems that usually have in-tank fuel pumps and operate at about 40-50 psi. The rated working pressure is 180 psi.
Vintage Corvette FI systems only need 30R7 (50 psi rated working pressure) because fuel delivery pressure to the fuel meter is less than 10 psi and there is no rubber hose beyond the fuel meter.
Manufacturers began reformulating elastomers to be compatible with so-called "gasohol" (E10) when it first became available in some parts of the country back in the eighties. Any auto parts store should have reels of modern fuel hose that they sell by the foot, and the SAE spec should be ink stamped along the length, so you know what you are buying.
This modern "low pressure" fuel hose is vastly superior and more durable than what was installed at the plant, and since you may not know the specs of "reproduction" fuel hose, I highly recommend use of modern SAE30R7.
The front hose (pipe to fuel pump inlet) is subject to more rapid deterioration than the rear hose (tank to pipe) because the front hose is subjected to higher heat, and if that hose ruptures the entire contents of the fuel tank will drain out. I recall reading a newspaper article back in the eighties that when apartment residents went down to their underground parking garage there was a strong gasoline order, and it turned out a Corvette had dumped all its fuel.
In my own experience, when the Air Force had me at Grand Forks from late '71 to mid '74 I stored my SWC in my parents Seattle garage. After the AF moved me to LA and I bought a house I flew up to Seattle to retrieve the SWC. I had drained the fuel tank for storage, so I poured in a gallon of gasoline, and guess what? Fuel started dripping out of that front hose. It had ruptured during storage! So I removed the hose and played little Dutch boy with my finger over the pipe while my dad took the hose down to a local gas station to get a new piece.
Don't take a chance. Use real SAE30R7 and just wipe the ink stamp data off with a little acetone.
Some recommend SAE30R9, but keep in mind that this hose is greater OD due to thicker walls and is much stiffer, so it will not bend to shape as easily as SAE30R7. Stick with with SAE30R7. It's more than adequate!
One other note - I'm sure that both the front and rear fuel supply hoses were just "generic" hose from a reel, not custom molded to shape like typical radiator hoses. The front and rear hoses had different part numbers because they were likely supplied by a vendor cut to length, not cut to length at the plant, and the part number changes over the years for the same hose may have been due to upgraded hose specs.
Duke
So-called "fuel injection hose" (SAE30R9) is for modern port EFI systems that usually have in-tank fuel pumps and operate at about 40-50 psi. The rated working pressure is 180 psi.
Vintage Corvette FI systems only need 30R7 (50 psi rated working pressure) because fuel delivery pressure to the fuel meter is less than 10 psi and there is no rubber hose beyond the fuel meter.
Manufacturers began reformulating elastomers to be compatible with so-called "gasohol" (E10) when it first became available in some parts of the country back in the eighties. Any auto parts store should have reels of modern fuel hose that they sell by the foot, and the SAE spec should be ink stamped along the length, so you know what you are buying.
This modern "low pressure" fuel hose is vastly superior and more durable than what was installed at the plant, and since you may not know the specs of "reproduction" fuel hose, I highly recommend use of modern SAE30R7.
The front hose (pipe to fuel pump inlet) is subject to more rapid deterioration than the rear hose (tank to pipe) because the front hose is subjected to higher heat, and if that hose ruptures the entire contents of the fuel tank will drain out. I recall reading a newspaper article back in the eighties that when apartment residents went down to their underground parking garage there was a strong gasoline order, and it turned out a Corvette had dumped all its fuel.
In my own experience, when the Air Force had me at Grand Forks from late '71 to mid '74 I stored my SWC in my parents Seattle garage. After the AF moved me to LA and I bought a house I flew up to Seattle to retrieve the SWC. I had drained the fuel tank for storage, so I poured in a gallon of gasoline, and guess what? Fuel started dripping out of that front hose. It had ruptured during storage! So I removed the hose and played little Dutch boy with my finger over the pipe while my dad took the hose down to a local gas station to get a new piece.
Don't take a chance. Use real SAE30R7 and just wipe the ink stamp data off with a little acetone.
Some recommend SAE30R9, but keep in mind that this hose is greater OD due to thicker walls and is much stiffer, so it will not bend to shape as easily as SAE30R7. Stick with with SAE30R7. It's more than adequate!
One other note - I'm sure that both the front and rear fuel supply hoses were just "generic" hose from a reel, not custom molded to shape like typical radiator hoses. The front and rear hoses had different part numbers because they were likely supplied by a vendor cut to length, not cut to length at the plant, and the part number changes over the years for the same hose may have been due to upgraded hose specs.
Duke
Comment