[65 Lamnas]

I've pretty much figured out a new fuel system for the '65 Lamnas. I'm going with a replacement tank with in-tank pump and I'm wavering on the size of the plumbing.
It's going to be a street-driven car (with an occasional rip at the dragstrip) n/a 461...should be in the 525-540hp range, and I'll be running a Q-jet....so lots of fuel volume at an appropriate psi will be critical for high-perf driving. Engine is about to be sent off for build.
So far, I've got the tank (and pump) picked out, filter, regulator.... I just don't know if I should step up to -8 hose and fittings everywhere or if -6 will be MORE than adequate.

[4zpeed]

Rule of thumb I use...

350-450 hp 3/8 in. -6

450-650 hp 1/2 in. -8



Frank

[Schurkey]

Originally Posted by 65 Lamnas

I just don't know if I should step up to -8 hose and fittings everywhere or if -6 will be MORE than adequate.

You aren't thinking of running hose from the tank to the carb...are you?

Using hose when metal (or hard plastic) tubing will work is crazy. Tubing is cheaper, lighter, has longer service life, and is less porous than rubber hose. Teflon- (PTFE-) liner hose isn't porous, but it's even more expensive.

Keep the hose length to the minimum--a foot or eighteen inches to allow for engine shake, for example, use tubing where you can.

[72projectbird]

Originally Posted by Schurkey

You aren't thinking of running hose from the tank to the carb...are you?

Using hose when metal (or hard plastic) tubing will work is crazy. Tubing is cheaper, lighter, has longer service life, and is less porous than rubber hose. Teflon- (PTFE-) liner hose isn't porous, but it's even more expensive.

Keep the hose length to the minimum--a foot or eighteen inches to allow for engine shake, for example, use tubing where you can.

I've been running AN line at 58psi the full length of my 71 for years now, with no issues.

[4dblnkldude]

I recently did PTFE for some trans lines, wow what a connection! Very strong! I, too, Would do -8 AN all the way. I vaguely remember some company making factory lines in half inch?

[steve25]

Once you get on the increased HP highway most of us get power hungry so go with 1/2” tubing and line and don’t look back.

[Skip Fix]

My 78 TA has had 1/2 AN frrm the external pump forward , switched to PTFE line after going back to pump gas and "regular SS rubber leaked. 3/8 hard line was not cutting supply to the Qjet at 450 hp. Camaro/IA has -8 feed and -10 return line PTFE the entire length .
Camaro has -6 PTFE to hard lines near the headers to and from the cooler.

[78w72]

Another vote for -8 or 1/2". I run a similar power engine with a q-jet and decided to go with 1/2" based on cliffs suggestion of using the biggest line possible for lower psi carb'd engines, EFI can get away with smaller -6 due to higher psi.

Braided hose does have a recommended life span, but from my experience & many friends that use it, it lasts 2-3 times longer than the 5-7 years some companies say. I have about 6-8' of summit brand non PTFE braided -8 hose from about mid door area to pump & pump to carb on a 2nd gen firebird, have pre bent 1/2" stainless from tank to there from right stuff detail. Been in use for about 10 years with no signs of any seepage or fuel smell issues.

A friend with a dedicated drag car SBC 72 nova that runs low 10s on motor & low 9s on NOS uses the same braided hose, -10 from fuel cell to pump & -8 from pump to carb & return line... been in use for almost 20 years with no issues, he wants to replace it but with little use these days & no signs of issues it gets put off each year. Other friend with a strip/street car been using braided line for 15+ years. Also braided line is much easier to run than bending metal lines if you cant or dont want to do that.

I dont doubt braided line has a limited lifetime, its usually not anywhere near as short as some claim... kinda like tires, some say you absolutely must replace tires at 5 years old regardless of miles or tread depth or condition.... way overkill if they are in good condition & within the rated mileage, theres probably multi millions of tires way older than 5 years on the road doing perfectly fine, but then again a 1 year old tire can fail depending on all kinds of different variables.

Decent quality braided line is fine to use & the vast majority will live much longer than the claimed life, or get the PTFE... or bend your own metal line if you can.

[Formulajones]

I do -8 on setups like that on both feed and return.

[BILL BOWMAN1]

Does anyone still make 1/2 steel straight lengths? I can’t find anything. I want 1/2 line but not braided, and nothing that comes in a roll.

[b-man]

Originally Posted by BILL BOWMAN1

Does anyone still make 1/2 steel straight lengths? I can’t find anything. I want 1/2 line but not braided, and nothing that comes in a roll.

https://www.mcmaster.com/product/9220K361-9220K36

Comes in a 6’ length at the longest. The last time I bought some I used .049” wall, the .035” wall kinks easily white bending.

Also 1/2” .049” wall stainless steel tubing should be available in 20’ lengths. I used to work with this at one of my old jobs building semiconductor processing equipment (high-vacuum thin-film sputtering and electron beam coating systems) and man that .049” wall tubing sure wasn’t easy to bend.

[Tim Corcoran]

Originally Posted by BILL BOWMAN1

Does anyone still make 1/2 steel straight lengths? I can’t find anything. I want 1/2 line but not braided, and nothing that comes in a roll.

1/2 aluminum fuel line is readily available at Summit, Jegs etc. It's easy to bend and will last longer than rubber steel braided line. And it does come in a roll.

[BILL BOWMAN1]

Thanks Bman

[JLMounce]

For a carbureted setup, I'd definitely do the -8 line. If you were EFI up to about 600ish hp you'd be fine with the -6 line. Remember a -6 line is equivalent to about 3/8 ID not 3/8 OD like hard line. There's a difference in flow capability there.

I like others have been running PTFE AN line for quite a while now. Since 2015 to be exact. Each time I think about going to replace it, I do inspections and it's all in great condition. I would not be afraid of it.

[Formulas]

Originally Posted by 65 Lamnas

I've pretty much figured out a new fuel system for the '65 Lamnas. I'm going with a replacement tank with in-tank pump and I'm wavering on the size of the plumbing.
It's going to be a street-driven car (with an occasional rip at the dragstrip) n/a 461...should be in the 525-540hp range, and I'll be running a Q-jet....so lots of fuel volume at an appropriate psi will be critical for high-perf driving. Engine is about to be sent off for build.
So far, I've got the tank (and pump) picked out, filter, regulator.... I just don't know if I should step up to -8 hose and fittings everywhere or if -6 will be MORE than adequate.

What pressure coming from tank?

[OCMDGTO]

Definitely 8an feed and return, do it right once

[Schurkey]

Originally Posted by steve25

Once you get on the increased HP highway most of us get power hungry so go with 1/2” tubing and line and don’t look back.

Originally Posted by OCMDGTO

Definitely 8an feed and return, do it right once

^^^ Yes.

Originally Posted by JLMounce

Remember a -6 line is equivalent to about 3/8 ID not 3/8 OD like hard line. There's a difference in flow capability there.

No.

Different brands/styles of hose have different internal dimensions. My experience with the hose I've actually worked with has been that most "Dash 6" hose is smaller than 3/8 ID, although some--the minority--actually was 3/8 ID. The same goes for the other sizes. "Dash 8" is rarely a true half-inch ID, Dash 12 is generally not 3/4" ID. MOST hose is approximately the same ID as tubing. There are some exceptions.

Some examples:

Aeroquip "AQP FCN06xx" has an ID of .380, slightly larger than 3/8".
https://www.summitracing.com/parts/aer-fcn0606

Summit house-brand Teflon-liner hose SUM-220985 has an ID of only .320.
https://www.summitracing.com/parts/sum-220985

Vibrant Performance -6 Teflon-liner hose also has an ID of only .320.
https://www.summitracing.com/parts/vpe-18976

Fragola -6 Teflon hose is only .312 ID.
https://www.summitracing.com/parts/fra-602026

Aeroquip "AQP FCA06xx" rubber-liner hose ID is .340.
https://www.summitracing.com/parts/aer-fca0620

In short...verify what you're buying, and make damned sure the hose ends you get match the hose.

And I still say it's nucking futs to use more hose than absolutely necessary. If it doesn't NEED to flex...you shouldn't be using hose in that application.

[65 Lamnas]

Originally Posted by Schurkey

^^^ Yes.


No.

Different brands/styles of hose have different internal dimensions. My experience with the hose I've actually worked with has been that most "Dash 6" hose is smaller than 3/8 ID, although some--the minority--actually was 3/8 ID. The same goes for the other sizes. "Dash 8" is rarely a true half-inch ID, Dash 12 is generally not 3/4" ID. MOST hose is approximately the same ID as tubing. There are some exceptions.

Some examples:

Aeroquip "AQP FCN06xx" has an ID of .380, slightly larger than 3/8".
https://www.summitracing.com/parts/aer-fcn0606

Summit house-brand Teflon-liner hose SUM-220985 has an ID of only .320.
https://www.summitracing.com/parts/sum-220985

Vibrant Performance -6 Teflon-liner hose also has an ID of only .320.
https://www.summitracing.com/parts/vpe-18976

Fragola -6 Teflon hose is only .312 ID.
https://www.summitracing.com/parts/fra-602026

Aeroquip "AQP FCA06xx" rubber-liner hose ID is .340.
https://www.summitracing.com/parts/aer-fca0620

In short...verify what you're buying, and make damned sure the hose ends you get match the hose.

And I still say it's nucking futs to use more hose than absolutely necessary. If it doesn't NEED to flex...you shouldn't be using hose in that application.

Good point about actual hose ID. All the more reason not to run the PTFE lined stuff...plus the bend radius is chit.

[JLMounce]

Originally Posted by Schurkey

^^^ Yes.


No.

Different brands/styles of hose have different internal dimensions. My experience with the hose I've actually worked with has been that most "Dash 6" hose is smaller than 3/8 ID, although some--the minority--actually was 3/8 ID. The same goes for the other sizes. "Dash 8" is rarely a true half-inch ID, Dash 12 is generally not 3/4" ID. MOST hose is approximately the same ID as tubing. There are some exceptions.

Some examples:

Aeroquip "AQP FCN06xx" has an ID of .380, slightly larger than 3/8".
https://www.summitracing.com/parts/aer-fcn0606

Summit house-brand Teflon-liner hose SUM-220985 has an ID of only .320.
https://www.summitracing.com/parts/sum-220985

Vibrant Performance -6 Teflon-liner hose also has an ID of only .320.
https://www.summitracing.com/parts/vpe-18976

Fragola -6 Teflon hose is only .312 ID.
https://www.summitracing.com/parts/fra-602026

Aeroquip "AQP FCA06xx" rubber-liner hose ID is .340.
https://www.summitracing.com/parts/aer-fca0620

In short...verify what you're buying, and make damned sure the hose ends you get match the hose.

And I still say it's nucking futs to use more hose than absolutely necessary. If it doesn't NEED to flex...you shouldn't be using hose in that application.

Thanks for the added information. Goes to show you've got to do the research on the individual selection.

Looks like hardline ID is all over the place as well. I've seen anywhere from .3 to .34 for 3/8's in steel, stainless and aluminum. Aluminum tending to have the smallest ID.

My lived experience with a car that gets driven in changing climates and often is that the PTFE hose has held up well. Right at about 30k miles since 2015 on Earles Push lock stuff. Summer, winter, dry and wet. Of course YMMV.

[Schurkey]

Originally Posted by HWYSTR455

There use to be some concern over puncture risk for aluminum, from like rocks and stuff, but unless you're doing pikes peak, think it a non-issue. If there are areas you're concerned about that seem to be exposed, you can use the spiral line covers. (Rock guard)

Anything is possible.

Far as I know, the concern with aluminum and copper tubing is vibration--the tubing is subject to work-hardening and then the hardened sections crack and leak. Note that I'm talking about "real" copper tubing, not the better, more expensive "NiCopp" nickle/copper alloy.

Originally Posted by HWYSTR455

Try to use AN fittings instead of less expensive JIC stuff, those can be frustrating to thread at times and sometimes leak.

I spent ten years working with "JIC stuff" on engine installations on city buses. We used tens of thousands of "JIC" fittings, adapters, and hose ends.

We did have some problems, nearly always resulting from The F'n New Guy who didn't pay attention when I told him/her how to do things. The second most-common problem was Aeroquip -4 female hose ends cracking from being over-tightened.

In short, except for what I consider to be a questionable design decision on the Dash 4 hose ends leading to them being overly-sensitive to installation torque (the sealing surface was a radius rather than a flat taper, so it could be used on 37 degree tapered fittings as well as 45 degree tapers) there is NOTHING wrong with "JIC" as long as you aren't using it on an aeroplane or spacecraft. For "ground transportation" they're Friggin' Wonderful.

Now--and I've gone off on this previously--There is no such thing as "AN" or "JIC" any more.

REAL "AN" is an obsolete standard for AEROSPACE/MILITARY use, "Army/Navy". Similarly, "JIC" was "Joint Industry Council", again an obsolete set of standards. The parts looked the same, and it was possible to use the high-grade, aerospace stuff in an application that only needed "industrial" quality--the threads were the same size and thread pitch, both used 37 degree tapers. They'd screw together just fine. The aerospace-quality stuff cost even more than the industrial-grade, and that is plenty expensive.

Both the Aerospace-grade items and the similar-looking "industrial" versions are now covered by SAE standards.

If someone is trying to sell you "AN" fittings, they're almost certainly actually providing industrial-grade stuff, that used to be considered "JIC" but isn't any more. Summit, for example, is NOT selling spacecraft/fighter-plane fittings out of their stock. Summit also does not sell "$400 toilet seats" and "$2000 coffee makers", either. Leave that to Government suppliers.

Originally Posted by Tim Corcoran

1/2 aluminum fuel line is readily available at Summit, Jegs etc. It's easy to bend and will last longer than rubber steel braided line. And it does come in a roll.

MAYBE that depends on what fluid you're transporting inside that tubing. But ordinary gasoline/diesel, you're probably right.

Originally Posted by 78w72

Isnt the ni-cop line supposed to be better than aluminum, & easier to work with?

I have very little experience with NiCopp tubing. I've made ONE pair of rear-axle brake tubes from the 3/16 stuff, and I had a terrible time producing a decent flare. I can flare the usual double-wall seamless steel tubing in 3/16 with no problem. The NiCopp forms so easily that I was getting wrinkles in the tubing instead of a decent flare.

I own a roll of some other NiCopp tubing sizes, but I haven't worked with it. I have no idea how my tooling would flare other sizes.

Originally Posted by JLMounce

Thanks for the added information. Goes to show you've got to do the research on the individual selection.

Looks like hardline ID is all over the place as well. I've seen anywhere from .3 to .34 for 3/8's in steel, stainless and aluminum. Aluminum tending to have the smallest ID..

Let's discuss plumbing.

PIPE is measured by the ID. So 1/2" pipe would have a nominal ID of 1/2 inch. Of course, most commonly-available iron pipe and iron pipe fittings/reducers/elbows are now coming from China, the threading is terrible and the ID is roughly-formed (it never was beautiful.) Brass pipe, elbows, reducers, etc., is formed nicely, also comes from China. The ID is closer to the nominal size.

TUBING is measured by the OD. So 1/2" tubing has a 1/2" OD, and the ID varies with the wall-thickness of the tube. Thinwall tube has a larger ID, thickwall tube has a smaller ID. The thickness of the wall is dependent on the material it's made from and also the pressure it's expected to take. So it's no surprise that aluminum tubing would need a thicker wall than steel, or it's rated for lower pressure, or both. When The Bus Company started building CNG- and LNG-fueled buses, we started getting acquainted with Swagelok fittings and the thickest-wall tubing I'd ever seen. But that's to be expected when the fuel is under 2000 psi plus some safety margin for the plumbing.

HOSE is kinda-sorta based on TUBING sizes, specifically a more-or-less equivalent to a similar-ID tube. And in the high-quality world, "AN", "JIC" or the equivalent modern SAE standards, it's usually described in sixteenths of an inch--a "Dash 4" hose is 4/16 or 1/4-inch, roughly equivalent to the fluid pathway of "typical" 1/4" tubing. Dash 8 hose is 8/16 or 1/2 inch, roughly equivalent to the fluid pathway of "typical" 1/2" tubing.




It makes me crazy when folks call plumbing "line" "lines" or "hardline" . Lines are imaginary objects in geometry. I try to make a point of using the terms "pipe" "tubing" or "hose" to describe my plumbing.

Are there exceptions to this description of "pipe" and "tubing"? Sure. Exhaust "pipe" is sometimes sold by ID and sometimes sold by OD, to make it easy to build slip-fit "lap joints". Are there hoses that are not spec'd to be similar to typical tubing? Sure. Is some plastic tubing flexible in a way you'd expect from hose? Sure.