[78w72]

Originally Posted by DaleO

Thank you 78w72, pictures not needed, I see that a 1/2" OD line will fit through there fine and it sounds like it will be able to take the slight curves necessary to hook up and not kink or anything like that. Do you have an in-line filter along with the regulator too? I've usually used in-lines as it seems the in-housing filters (short/long) are so small but I see that Cliff sells pleated filters so they must be able to do the job. It would be a cleaner instl without.

The clockability is a cool feature. I'm really impressed with the quality and heft of the unit.

Just an FYI, the pump I took out had the outlet (bottom) on the same side of the pump as the inlet (1969 428) and I also looked at the pump on the 1969 400 in my other car and the outlet is on the opposite side of the pump. I would not claim either configuration is original or correct or whatever but the lines for both go up between timing chain cover/pump bracket/head.

thank you for your help

Yes a 1/2" line will fit like the factory routing, even a custom made steel 1/2" line should fit but the braided line makes its an almost straight run under the p/s pump & under/behind the alt with nothing even close to kinking... i did put a slit piece of heater hose over the line where it barely rests against the alt bracket just to be safe but no sign of any issues after 7-8 years. Can also put a section of heat shield on the line if thats a concern but ive never had any heat related issues with fuel.

I have filters, one bigger tanksinc right after the tank then just use the marine screen type right before the carb, cliffs AN fitting uses the high flow marine screen type, im sure you can use the factory pleated paper type too but the marine filter is supposed to flow better. I have checked both filters a couple times after years of use and the carb one is always spotless and so is the bigger one but it has a brass element so harder to see if there are any small specs in it, looks totally clean to me, i do have a new tank so no debris to get churned up. I dont have or feel the need for any other inline filters.

Heres a pic just to show the carb AN fitting & how the line is ran, i have since shortened the line a bit & now run a regulator for when I want to dial the 1100 pump up to a higher psi for track use but a regulator shouldnt be needed for most carbs with the 550 pump since its set at ~7psi.

[Formulajones]

I've done 1/2" steel line from pump to carb on some installs. It fits and works. Just a little tedious and time consuming but it all is really.

[Cliff R]

You can support big HP with pretty much "stock" fuel systems and simply a mechanical pump upgrade right up untl the moment you take steps to make the car hook really hard and pin you in the seat on the launch

At this point sucking fuel some 14' or so from a stock in tank sump with stock lines will not longer make the grade.

What muddies the water here is that some folks post they they get away with it run on down into the 11's and some even on into the 10's without any further upgrades when most folks trying to do the same thing can't get out of the 13's.

I went thru the entire evolution with my car when I started installing bigger engines, more gear, converter and good tires. At the end of all the efforts to keep the carb full on hard runs I ended up sumping the tank and installing a 140gph pump behind the tank and 8AN lines/fittings everywhere.

That move INSTANTLY solved any and all fuel delivery issues and the car picked up a solid 2-3 tenths and at least 3-4 mph. That was just on the first outing. I made a few more changes and went on to run much quicker and never again experienced any fuel delivery issues whatsoever.

Since technology has improved considerably if I were doing it over again I'd go right to an in-tank system and "push" all the fuel and run a full return back to the tank. Then, as mentioned someplace above I could continue to make changes to make more power and go faster at the track without having to re-visit fuel delivery issues.......FWIW.......

[PAUL K]

I was taught when you want to run 12's you need to upgrade to 1/2 inch fuel line....that was forty years ago and pump technology has changed a bunch but that rule never failed me.

At 500 HP I'd think 1/2 would be helpful. I ran 1/2 with a hidden baffled pick up drawing from the front of the tank with a Holley blue pump for years. That worked fine for low ten second ET's but once we upgraded to nine second power I added a sump and better fuel pump to make things happy.

[77 TRASHCAN]

Originally Posted by PAUL K

I was taught when you want to run 12's you need to upgrade to 1/2 inch fuel line....that was forty years ago and pump technology has changed a bunch but that rule never failed me.

At 500 HP I'd think 1/2 would be helpful. I ran 1/2 with a hidden baffled pick up drawing from the front of the tank with a Holley blue pump for years. That worked fine for low ten second ET's but once we upgraded to nine second power I added a sump and better fuel pump to make things happy.

Paul,
What fuel setup do you have on that pretty light blue TA of yours?

[PAUL K]

Originally Posted by 77 TRASHCAN

Paul,
What fuel setup do you have on that pretty light blue TA of yours?

That's the car I was talking about. I always wanted that car to look "stock". For years I ran two Holley blue pumps. One through the factory 3/8 line for the nitrous and one for the motor side. I added a peice of .500 tubing that entered the front of the tank but ran to the rear. That set up worked well when the car ran bottom 11's and low tens on spray. When we upped the power it became inconsistant and the pressure gauge moved around more than I liked. No matter what I tried I couldn't get it to work to my satisfaction so I ended up installing a new tank with a sump.... Now I need to build another car to use the old tank

[Formulajones]

Pretty simple to make them look stock with a little thought and time.

I use the Tanks Inc tanks with the pump in the tank. No sumps hanging down. I run the 1/2" line, sometimes using stainless pre bent stuff from places like Inline or Right Stuff, which gives the appearance of stock if anyone cared to crawl under the car.

I then keep the stock mechanical pump in place if it's visible (like a Chevrolet) and keep the stock steel lines running to the carb or EFI, although it's all dummy stuff with the line soldered shut.

The 1/2" line I hide in the back where it can't be seen.

Look under the car or open the hood and it looks like a typical street car with a mechanical pump but it actually has a fuel system that'll support 1000+ HP depending on which pump I put in the tank

[DaleO]

Thank you 78w72 and Formulajones. My plan is in place and putting the parts list together.

[grivera]

Is the situation different for EFI? With an in-tank EFI pump is the goal to maintain the fuel pressure required at the throttle body and sizing the fuel line to meet said PSI?

[PunchT37]

You’ll be borderline on the street. Upgrade if you hit the track. My old 470 ish hp 455 did well on the street. At the track, it would pop through the air cleaner just before the line at the top end. Pulled the plugs. All white like a bed sheet.

[Formulajones]

Originally Posted by grivera

Is the situation different for EFI? With an in-tank EFI pump is the goal to maintain the fuel pressure required at the throttle body and sizing the fuel line to meet said PSI?

I don't have a bunch of experience with EFI at the track other than racing LS engines back in the 90's and early 2000's. All those vehicles had smallish factory fuel lines, but they also pump 58 psi fuel pressure too. I ran them into the 11's and near 120 mph without issue but I did upgrade the factory in tank pumps. Others were going even faster with them back then.

Pressure is one thing, volume is another, I'm sure you're aware.

Whether it matters or not, when I'm doing a moderately high HP EFI build, I just run the 1/2" lines to and from and be done with it. One reason is because I'm typically replacing fuel lines on a build anyway, so I just upgrade to 1/2", the cost is the same.

Ironically both of our current EFI cars (one running 10's and the other 11's) already had 1/2" lines and in tank pumps when they had carbs, so all of that was left in place when the switch to EFI was made.

[64speed]

Send Caster1 a DM and ask him about his setup, it has a 1/2 pickup and a few other mods. Its pretty sick.

[Skippy597]

Ok so I got a robbmc 1/2" pickup and inline tube 1/2" fuel line on the way. Now my question is do I need to get a 1/2" carb feed line from the pump or will the robbmc pump supply suffecient pressure with a 3/8" line.

[Formulajones]

Ive done 3/8 from the pump to carb or the regulator to carb to make things look stock and works fine. 1/2" is always better but the most important thing with a mechanical pump is having the larger feed line on the suction side because they aren't good at sucking, that's a long distance and making it as easy as you can on the pump with larger line helps that scenario.

[78w72]

Agreed the bigger pump to carb line isnt always required, but, if you have a Q-jet & dont care about an original looking/size line, using a 1/2" or -8 AN line will provide a little more fuel from pump to carb if that matters. Its easy to run a -8 line from the robbmc pump outlet to the carb using one of cliffs -8 AN fitting & high flow marine filter.

[DaleO]

Originally Posted by 78w72

Agreed the bigger pump to carb line isnt always required, but, if you have a Q-jet & dont care about an original looking/size line, using a 1/2" or -8 AN line will provide a little more fuel from pump to carb if that matters. Its easy to run a -8 line from the robbmc pump outlet to the carb using one of cliffs -8 AN fitting & high flow marine filter.

This is very timely for me, very. My RobbMC came this week and I took out the old pump last night. I've been making a plan for needed fittings and was about to head out to the garage and check about the routing to the carb. The 3/8 outlet comes out the opposite side of the pump's inlet so it looks like I'll be using a 90 degree fitting to come out and straight up. Summit has a line (PTFE) by Fragola with this fitting feature already as assembly. I was going to determine if the line would fit through the factory routing between power steering pump bracket and timing chain cover. I, however, don't know the 3/8 line O.D. nor the bend radii of the line to see if this is possible. This obviously has everything to do with picking the correct line length as well. If I can't snake a 3/8 line through the original routing and have to find a different path I will go with a 1/2 line but where does it run? It must come up around the outside of the alternator and over or behind it over the valve cover? Im not concerned about original routing but am very cautious of moving parts (fan, pulleys, belts, alternator and pump adjustment) and electrical and headers....You already know that....Does anyone have a hint or even a picture?

[78w72]

I have an older version of the robbmc 1100 pump, not sure if the inlet/outlets are the same as newer models or the 550, but I used a summit or fragola brand curved 90 AN fitting on the outlet then ran the -8 braided hose up behind the p/s pump & alternator basically where the stock metal 3/8 line runs, -8 line is about 1/2" OD so its a lot bigger than 3/8 line, it slides through that area easily and is nowhere near moving parts or belts, its rigid ennough that it stays in place... i even added a small regulator to it that sits near the T-stat housing freely suspended with no bracket. i can get some pics of how its routed but its really pretty basic.

Dont forget the robbmc pump is clockable so you can adjust where the inlet/outlets are somewhat.