Who Has Upgraded Their Fuel Line From 3/8" to 1/2"?

[Les]

I'm almost ready to swap in an Ultradyne cam & they told me to be prepared to also upgrade my fuel line to 1/2" due to the increased flow that this cam seems to need. I'm wondering what I'll need to get besides the hard line, where the best place is to get it, how to deal w/ the fittings at the tank & fuel pump, and what to do w/ the return line that's part of my stock system. Thanks in advance for any info. :cheers:

[norvalwilhelm]

I upgraded both my cars to 1/2 inch hard line. For the mustang I used the aluminum line from summit with percussion fittings and it came out fine. For the vet I used lengths of 1/2 inch stainless. It was alot harder to work with and required a dedicated pipe bender and once again used percussion fittings.
In both cases I weld new outlets to the bottom of the tank, twin outlets that fed into large fuel filters that fed into twin holley high pressure pumps then into a single 1/2 inch line leading to fuel pressure regulators.
In my case I do not trust a single holley pump and always run 2 on seperate switches. I only run on one most of the time and alternate which one I am using. I keep 2 spares in the shop just in case.
Not a cheap deal, 2 pumps, 2 large fuel filters, the 1/2 inch lines, a very expensive holley regulator plus dropping the tank for new outlets.
I don't worry about my fuel system anymore. :)
I didn't mean I run the pumps on seperate switches. Don't run them on switches, run them on relays and use the switch to activate the relay.
Anything that draws real power should run off a relay and not a switch.


[Modified by norvalwilhelm, 8:09 PM 4/19/2003]

[Ironcross]

It`s really not necessary unless your using a supercharger and the related high pressure pump driven off the camshaft in front of the engine. Unsupercharged engines up to 600HP survive easily without anything more than 3/8`s and mechanical pumps as long as you have the correct combination. 5/16`s would never work. :cheers:

[Les]

Norval,
Thanks for the good info- I'll print & save it in case I need it. :cheers:
I was waiting to make a phone call before I replied. Keep reading below...

Ironcross,
Thanks- I was hoping that I wouldn't have to go through the hassle & expense. After calling a respected local shop today I'm hoping more than ever that you're right. The cost of the line isn't much but the cost of the install, including dropping the tank & modding it for 1/2" outlet, was estimated at 6 hours- at a shop rate of....are you sitting down?.....$95 per hour! :eek: I'll definitely try it first w/ my new cam/heads combo before making any other changes. :cheers:

[black bart]

Norval,
Thanks for the good info- I'll print & save it in case I need it. :cheers:
I was waiting to make a phone call before I replied. Keep reading below...

Ironcross,
The cost of the line isn't much but the cost of the install, including dropping the tank & modding it for 1/2" outlet, was estimated at 6 hours- at a shop rate of....are you sitting down?.....$95 per hour! :eek: I'll definitely try it first w/ my new cam/heads combo before making any other changes. :cheers:

$95 per hour Dam I'm glad I can do all of my own work
Since my car spends most of it's time on the street I didn't want to have a huge pump and lines hot lapping fuel back to the tank so I installed dual pickup tubes in the fuel tank ran dual fuel lines and pumps but I drive on one pump until 3500 rpm and then a MSD rpm switch starts the second pump. I installed a check valve in the left side line right side line feds fuel rail with cross over tube to the left side. The one pump easily feeds every thing for normal drive. I replaced oem pump each pump is good for over 600 hp works real well. :cheers:

[DeenHylton]

Unless your also going to dual carbs or nitrous your combination shouldn't need a larger line. Your stock 3/8" line and a Holley mechanical pump will easily support 500-550 HP.
Deen

[redvetracr]

-8 aeroquip stainless braided, not quite 1/2" but it works for me. But the -6 worked great also. ...redvetracr

PS: have you ever talked with Harold (Ultradyne) he is quite a character besides being a genius!!

[71coupe]

Les - If you are going to mod the tank, why don't you try installing a sump kit at the bottom of the tank? - I think it would be cheaper than your current tank mod estimate. They sell the kits in Summit & Jegs. Monty's car has this setup as well - & I'm sure he could give you more info on this.

[Les]

Deen,
Most estimates based on my combo put me from 510-550+ HP(I expect it to be towards the lower end of the range), so it's gonna be a close call.

71coupe,
Thanks for the info- I'll check my catalogs today. :cheers:

[Les]

redvetracr,
I almost missed your comment about Harold- yes, I've talked to him 2-3 times now. He's got a ton of cool stories if you've got the time to listen. He also explained, in great detail, the theories on why he makes his cams the way he does. I got most of it but I wouldn't dare claim I understood it all. I do know they work- I've been running an Ultradyne solid flat tappet in my smallblock for many years now & it screams! :yesnod:

[wallyknoch]

Realistically, more like 400HP or less. :yesnod: If you want more HP, at least build it to a L72 engine with 11-1 pistons, solid lifter cam and square port heads and you can at least get an honest 425HP :thumbs:

[Les]

Realistically, more like 400HP or less. :yesnod: If you want more HP, at least build it to a L72 engine with 11-1 pistons, solid lifter cam and square port heads and you can at least get an honest 425HP :thumbs:

wally,
Thanks for the reality check. With the slightly modded original oval port heads(now being replaced w/ Edelbrock aluminum Performers which outflow the Chevy rect. port heads- refer to Chevy High Performance website) and a Crower hyd. flat tappet cam w/ duration of 220/226 @ .050 and lift of .517/.529 this motor put out 358 HP at the rear wheels. If you account for a 20% drivetrain loss w/ the auto trans(pretty much the accepted minimum loss), you can see that I was comfortably making mid-400 HP with the old combo.

Now add the new solid flat tappet cam w/ duration of .243/.251 @ .050 and lift of .586/.601 AND the new heads & you may see why I have trouble seeing how I'll lose 50+ HP from my old combo. I would be happy if I exceed 500 HP w/ the new combo- I have no specific expectations.

By the way, Edelbrock (using a hydraulic cam w/ similar duration & less lift than my new cam) built a 454 w/ the same heads I'm going to use and made 540 HP using a comp. ratio of 9.5 to 1....Can you see why I'm a bit confused? :thumbs: :thumbs:

[wallyknoch]

The low compression bothers me. L88`s run 12.5-1 and so do LS7`s. A solid lifter camshaft WILL give you close to what you want as the cam you selected as a solid lifter one is basically close to a LS7 cam. And will give you the necessary RPM`s needed to get near 500HP. In my LS7, I just took the 580/620 out and replaced it with a little taller Federal Mogul no. CS1110R, and added a polished {we shined them up} set of big Dart heads. Now I need a set of .200 longer push rods and I can finish the car again. Comenting on Edelbrocks 454 and getting all that horsepower with a hydraulic cam, and low compression, I can`t figure it out. Maybe I`m making more than I think. All I know is press on the gas and be the quickest to the lights and your making more HP whatever it is than the guy you beat. I hate bracket racing and dialing all those numbers. Heads up is what i`m use too. Good Luck with it Les. Your last post with your additions are more to my liking, :thumbs: I can tell you what and how my combination works in my street racer {kicked me out of the track as going too fast without a roll cage}and you can compare

Realistically, more like 400HP or less. :yesnod: If you want more HP, at least build it to a L72 engine with 11-1 pistons, solid lifter cam and square port heads and you can at least get an honest 425HP :thumbs:

wally,
Thanks for the reality check. With the slightly modded original oval port heads(now being replaced w/ Edelbrock aluminum Performers which outflow the Chevy rect. port heads- refer to Chevy High Performance website) and a Crower hyd. flat tappet cam w/ duration of 220/226 @ .050 and lift of .517/.529 this motor put out 358 HP at the rear wheels. If you account for a 20% drivetrain loss w/ the auto trans(pretty much the accepted minimum loss), you can see that I was comfortably making mid-400 HP with the old combo.

Now add the new solid flat tappet cam w/ duration of .243/.251 @ .050 and lift of .586/.601 AND the new heads & you may see why I have trouble seeing how I'll lose 50+ HP from my old combo. I would be happy if I exceed 500 HP w/ the new combo- I have no specific expectations.

By the way, Edelbrock (using a hydraulic cam w/ similar duration & less lift than my new cam) built a 454 w/ the same heads I'm going to use and made 540 HP using a comp. ratio of 9.5 to 1....Can you see why I'm a bit confused? :thumbs: :thumbs:

[Les]

wally,
The cam is degreed in @ 6 degrees advanced per Harold, which should help a bit with cylinder pressure. He's not concerned & says it will peak at about 6200 RPMs with a very fat torque curve, which would make 6500+ a pretty good shiftpoint. He says it'll pull 7200 RPMs but I don't see the need to go there.
Thanks for the good wishes...& yes, I'd be interested in more info on your combo & what your results have been. Also, I agree on your preference for heads up racing- I'm not into backing off to win a race but dialing in is the only option where I race.

[wallyknoch]

Well Les, It was a stock crate 454 LS7 which does not come with a intake. We used the L88 open plenum intake and a 850 with GM HEI ignition at 38 degrees, stock fuel pump and Hooker comp 2 1/4 tube headers into 3 in Walker race mufflers and dumped them out in front of the tires to blow the dirt off the track. Chassis is a stock looking 396 68 SS Camaro, modified stick shifting turbo 400, 3500 stall converter driving into a 4.56 gear and 9 in slicks. Just brake torking, the piece it runs solid mid 11`s, with 11.42 best at 119 mph with the STOCK LS7 shifting at 6800. The new Dart heads have bigger valves and we ported and matched all runners of the intake and heads and with the new camshaft installed straight up it should run a little better. The reason for straight up on the cam is I don`t need the bottom end with the 4.56 gear. The 60 foot times were 1.5-1.6. I don`t know when I`ll finish the piece, {soon I guess}. But without a roll cage they kicked me out before, but not until I found out what it could do. Make sure you use larger pushrods, they are available up to 7/16`s. I don`t care for roller anything {rockers and lifters} as to much junk to F--- up. I did drive it on the street with av-gas and as soon as George Delorian comes out with the longer push rods I will drive it again. If your using the engine is in a Vette, you may experience as good if not better than this type of performance. Have fun! :D

[Les]

wally,
You should pick up plenty from the new heads alone & a bit more from the new cam. If your trap speeds hit low-mid 120s you should be very close to a 10 second ride. Your 60 ft. times are great- I'll never come close to that since my class only allows D.O.T. approved tires. I bought a set of Sportsman Pros before MT came out w/ the ET Streets & don't have that many runs on them, so I'll keep em & see how I do next time out. Last time I ran(3-4 years ago) was before I swapped from stock intake/hood to Edelbrock RPM Air Gap & L88 hood- I ran a string of 112+ MPH trap speeds with the old set up, so I'm dyin to hit the track w/ the car when I'm done.
Keep us posted on how your mods work out. :thumbs:

[SmokedTires]

Do the rules stay the same when going from a carb to efi ? DD estimates my sbc 388 to be close/ around 600 hp when complete. I will be installing a high pressure pump for the efi. Should I step up to 1/2" or will the 3/8" be ok ? :cheers: