450 HP Fuel line diameter
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8th Gear
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450 HP Fuel line diameter
I just replaced the original steel line with 3/8 in aluminum line because it was way easier, same size. I'm putting in a 383 in the next couple of weeks. Is that line going to be big enough to support the fuel flow required for 450 HP? The inside diameter is .25. I really don't want to re-replace the fuel line.
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Yes you'll be fine with a good pump and no restrictions in the tank or inline filters before the pump. I assume you're running a mechanical pump?
JIM
JIM
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Yeah, it's a mechanical pump. Thanks. Some places were recommending a 3/8 ID (AN6) line, but I haven't heard on anyone putting in bigger fuel lines with an engine swap.
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On my 77. The original fuel lines were 3/8th's ID feed and 1/4 return. When I went over to EFI, I went with 3/8th's ID for both.
I'm running approximately 400 HP. I have not heard of anyone running a 1/4 inch ID feed line on a V8. Regardless of type of pump.
I'm running approximately 400 HP. I have not heard of anyone running a 1/4 inch ID feed line on a V8. Regardless of type of pump.
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Yes normally there is no change to hard fuel line because it's steel which has a larger inside diameter than aluminum. You will have to test your actual fuel pressure to see if the aluminum line is too restrictive.
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Its not pressure, its flow....Im running stock steel 3/8 line with AN-6 steel braided on a 580hp 427. I dont think you will have enough flow for long high rpm pulls with 1/4 in inside diameter...3/8 steel probably is still closer to 5/16....
Good luck
Good luck
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Im in the same gross HP range as your 383 with my 355 L-82 and I am still using the L-82 OEM factory steel fuel lines from the tank and from the replacement standard AC Delco mechanical fuel pump-ZERO issues with fuel capacity.
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You do know your fuel line inside diameter is larger than what the OP is using?
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I am still using the L-48 OEM factory steel fuel lines from the tank to a Cater Super Street 120gph mechanic pump on my 427ci small block, took it to 7000rpm's on chassis dyno with no problems. Secs below 
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Yes and the OEM fuel line is 3/8th's ID.
Old Pro Solo Guy
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Umm...there are some errors in some above posts:
OP...you will be fine.
Hard lines are measured in O.D. Hose is measured in I.D. Apples and oranges.
Aluminum and steel hardlines have almost exactly the same I.D. due to design, and wall thickness.
A.I. sums it up:
A \(3/8\)-inch (\(0.375"\)) OD (Outside Diameter) steel or aluminum fuel line generally has an inside diameter (I.D.) of approximately \(0.30\) to \(0.32\) inches, depending on the wall thickness. Common wall thicknesses of \(0.035\) inches result in an I.D. of roughly \(0.305\) inches, while thinner \(0.028\)-inch walls result in a \(0.319\)-inch I.D.. [[url=https://www.ebay.com/itm/147083097922]1, 2]
Key I.D. Measurements for 3/8-inch Lines:
Note: For comparison, a 3/8" flexible rubber braided hose typically has a full 3/8" (\(0.375"\)) I.D., unlike the hard line equivalent which is smaller due to tube wall thickness. [[url=https://www.google.com/search?q=product&prds=pvt:hg,productid:4 837760955685880950&ibp=oshop]1, 2]
OP...you will be fine.
Hard lines are measured in O.D. Hose is measured in I.D. Apples and oranges.
Aluminum and steel hardlines have almost exactly the same I.D. due to design, and wall thickness.
A.I. sums it up:
A \(3/8\)-inch (\(0.375"\)) OD (Outside Diameter) steel or aluminum fuel line generally has an inside diameter (I.D.) of approximately \(0.30\) to \(0.32\) inches, depending on the wall thickness. Common wall thicknesses of \(0.035\) inches result in an I.D. of roughly \(0.305\) inches, while thinner \(0.028\)-inch walls result in a \(0.319\)-inch I.D.. [[url=https://www.ebay.com/itm/147083097922]1, 2]
Key I.D. Measurements for 3/8-inch Lines:
- Aluminum (\(0.035"\) wall): Approx. \(0.305" - 0.319"\) I.D. (3003 or 1060 alloy).
- Steel (\(0.035"\) wall): Approx. $0.305" I.D. (standard for hard lines).
- Typical 3/8" AN Fitting (6AN): Matches a \(3/8"\) OD tube, providing a smooth flow transition. [[url=https://www.ebay.com/itm/147083097922]1, 2, 3]
Note: For comparison, a 3/8" flexible rubber braided hose typically has a full 3/8" (\(0.375"\)) I.D., unlike the hard line equivalent which is smaller due to tube wall thickness. [[url=https://www.google.com/search?q=product&prds=pvt:hg,productid:4 837760955685880950&ibp=oshop]1, 2]
Last edited by leigh1322; Yesterday at 08:07 AM.
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Umm...there are some errors in some above posts:
OP...you will be fine.
Hard lines are measured in O.D. Hose is measured in I.D. Apples and oranges.
Aluminum and steel hardlines have almost exactly the same I.D. due to design, and wall thickness.
A.I. sums it up:
A \(3/8\)-inch (\(0.375"\)) OD (Outside Diameter) steel or aluminum fuel line generally has an inside diameter (I.D.) of approximately \(0.30\) to \(0.32\) inches, depending on the wall thickness. Common wall thicknesses of \(0.035\) inches result in an I.D. of roughly \(0.305\) inches, while thinner \(0.028\)-inch walls result in a \(0.319\)-inch I.D.. [[url=https://www.ebay.com/itm/147083097922]1, 2]
Key I.D. Measurements for 3/8-inch Lines:
Note: For comparison, a 3/8" flexible rubber braided hose typically has a full 3/8" (\(0.375"\)) I.D., unlike the hard line equivalent which is smaller due to tube wall thickness. [[url=https://www.google.com/search?q=product&prds=pvt:hg,productid:4 837760955685880950&ibp=oshop]1, 2]
OP...you will be fine.
Hard lines are measured in O.D. Hose is measured in I.D. Apples and oranges.
Aluminum and steel hardlines have almost exactly the same I.D. due to design, and wall thickness.
A.I. sums it up:
A \(3/8\)-inch (\(0.375"\)) OD (Outside Diameter) steel or aluminum fuel line generally has an inside diameter (I.D.) of approximately \(0.30\) to \(0.32\) inches, depending on the wall thickness. Common wall thicknesses of \(0.035\) inches result in an I.D. of roughly \(0.305\) inches, while thinner \(0.028\)-inch walls result in a \(0.319\)-inch I.D.. [[url=https://www.ebay.com/itm/147083097922]1, 2]
Key I.D. Measurements for 3/8-inch Lines:
- Aluminum (\(0.035"\) wall): Approx. \(0.305" - 0.319"\) I.D. (3003 or 1060 alloy).
- Steel (\(0.035"\) wall): Approx. $0.305" I.D. (standard for hard lines).
- Typical 3/8" AN Fitting (6AN): Matches a \(3/8"\) OD tube, providing a smooth flow transition. [[url=https://www.ebay.com/itm/147083097922]1, 2, 3]
Note: For comparison, a 3/8" flexible rubber braided hose typically has a full 3/8" (\(0.375"\)) I.D., unlike the hard line equivalent which is smaller due to tube wall thickness. [[url=https://www.google.com/search?q=product&prds=pvt:hg,productid:4 837760955685880950&ibp=oshop]1, 2]
A 3/8-inch hard steel fuel line typically
has an outside diameter (OD) of 0.375 inches, with an inner diameter (ID) of roughly 0.319 to 0.325 inches, assuming a standard \(0.028\)-inch wall thickness. For flexible braided steel fuel hose, the inside diameter is usually a full 3/8 inches (\(0.375\) inches).
Old Pro Solo Guy
Joined: Dec 2017
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From: Marlton NJ
Agreed I would expect the wall thickness of steel to be slightly less than aluminum.
But even with a slight difference in wall thickness, the OP will still be fine.
This is only a .014" or 1/72" difference in internal I.D.
My point is it is not .375" (3/8") I.D, 3/8" hard lines are .319" or .309" I.D.
AN-6 fittings are misunderstood, The hose is bigger, but not the fittings. They are aluminum and slip inside the hose. Just like 3/8 hard line would.
Many Camaros back then use 5/16" O.D lines, with only .250" I.D. Now those were a problem.
Some Camaros and all Corvettes used the bigger 3/8" lines. Even for L88s.
3/8" is typically good enough for 500 to even 600HP
But even with a slight difference in wall thickness, the OP will still be fine.
This is only a .014" or 1/72" difference in internal I.D.
My point is it is not .375" (3/8") I.D, 3/8" hard lines are .319" or .309" I.D.
AN-6 fittings are misunderstood, The hose is bigger, but not the fittings. They are aluminum and slip inside the hose. Just like 3/8 hard line would.
Many Camaros back then use 5/16" O.D lines, with only .250" I.D. Now those were a problem.
Some Camaros and all Corvettes used the bigger 3/8" lines. Even for L88s.
3/8" is typically good enough for 500 to even 600HP
Last edited by leigh1322; Yesterday at 11:05 AM.
