swoodard23

I'm getting prepared to install a BOSS EFI system on my 77 corvette and am weighing my options. My kit does not require a return fuel line if I stay under 500hp (which I will). Is the stock steel line from the tank to the fuel pump sufficiently strong to withstand the 45psi operating pressure? Can it be rebent to terminate closer to the top of the engine? I know all rubber line will have to be replaced with FI rated hose. Thanks in advance.
Scott

mrvette

Yes to all of our questions.....I been running a return even off my stock lines for some 15 years now....TPI/LT1 type induction...near 400 hp, 355 ci......

never been a issue...

swoodard23

Thanks, good to know. Maybe that will save me some trouble. I am not planning on using a return fuel line. How should I cap it or do I need bother?

7t2vette

What kind of connector do you use to connect the high pressure flex line to the stock hard line? I am converting to EFI, and would like to use the stock feed and return hard lines.

corvettedave383

http://www.summitracing.com/parts/AER-FBM1232/

try this link, I used -8 an aeraquip fuel line, all the way to the tank, and used one of these connections to go from -8an, to -6an barb to fit smaller fuel hose, that will fit onto your hard fuel line.

I use a fuel regulator that flows fuel all the time, so you can use your exisiting, return line, my regulator takes a -4an fuel hose, which is the same size as the factory return line

dave

RodTeq

I have the Boss EFI in my 1970 with a 383. I ran a new 3/8 supply line and used the original return line. Seems to run well. IMHO the return line should be used to keep the fuel pump and fuel lines cool.
I used "an" fittings at each connection and a pressure regulator with the return port on it. The bulkhead fittings all leaked and required teflon tape to seal. The flare fittings worked well but be sure to not over-tighten them.
I like the EFI but you have to be careful what it learns. After a session at the drag strip it learned some bad habits. Be sure to save a file that you like so you can reload it later.
Good Luck. Rob

7t2vette

Hey Dave, I'm confused on how that fitting was used in your case. Did you run -8 hard line to the tank? I am trying to use my stock existing hard lines, in my case stainless 3/8" feed and stainless 5/16" (might be 1/4" can't remember 100%) and I need to figure out how to connect AN hose to these hard lines. I think I might need to flare my hard lines to make it work, but I don't know what fittings to use and I guess I will need to get a 37 degree flare tool. I was at a local cruise night last night, and I met a guy with an awesome '68 Firebird that was running the Edelbrock EFI system on a 540 big block....he had AN hose slipped over a hard line and secured with two hose clamps, an I asked him if he had any leakage problems and he said no. I guess that would work, but it seemed a little dodgy to me.

A little off topic here, but I notice that you are from Glasgow, I've been to Glasgow several times, my wife was born in Dundee. Next time we are over, I'll have to look you up so we can chat vettes over a few bevvies!



Hey Rob, just curious why you didn't use the stock 3/8" line?

corvettedave383

Hi, yeah I run a -8an aeroquip hose from the fuel pump at the front to the fuel tank at the back, I used that connection to reduce down to -6an size to fit onto hardline at fuel tank, I have my return line (-4an), fitted directly onto exsisting return line, just fitted using hose clip, no leaks atall, low pressure tho.

you could use a mechanical pump that produces high pressure, I use a "racepumps" mechanical pump, it pushs out 150psi, 450gph, and there regulator, therefore you only need to worry about one high pressure line, from the pump to the regulator and carb/fuel injection unit

so the old system can be used, but simple hose clip connection can be used, because low pressure from tank to pump

I live near Glasgow, a place called Bonnybridge, famous for UFO's, and very close to the falkirk wheel, yeah if your over in the future, would be great to meet up and talk vette's and stuff(ufo's lol), was your wife in scotland for long??

cheers

dave

72LS1Vette

If your stock steel line is in good condition it should be fine. If it isn't you'll find out soon enough. I don't know if you can re-bend the original line to get it closer to the top of the engine - if you do it will be back near the firewall.

Checkout this hardline-AN adapter from Earl's. I'm using one for my LS1 swap and have seen no leaks. There is a video about it on the Earl's website.

EAR-165006ERL at Summit Racing.



Rick B.

RodTeq

Hey Rob, just curious why you didn't use the stock 3/8" line?
As mentioned in this thread, I could not easily connect the 3/8 stock hard line to my an flare fittings...I used braided ss fuel hose. This allowed the Russel fittings to be easily added for the fuel pump, filters, regulator and fuel rail. Actually, there are pipe to an fittings available so you do not have to flare the hard line...not sure if they will hold 45 psi however. Rob

7t2vette

Do you have a link to the video? I can't seem to find it. Does the red part of the fitting and the compression ring slide over the hard line and when it is tightened it is sealed? If so, that would be a pretty simple solution.



I was at a car show last night and I saw 2 cars running the Holley TBI system. Both cars used the stock hard lines the same way: they flared the hard line with a brake tube flare tool and used a brake line type fitting into a double female adapter with NPT threads on the other side then a NPT to AN adapter. Thats also seems pretty simple.

72LS1Vette

I can't find the link to the video. Looks like Holley re-did their website. That is exactly how the fitting works. They claim the fitting is good for up to 100 PSI.

This solution works also. I did that at the tank end of my fuel line because I needed a push-in quick connect for the C5 fuel filter. I find it hard to do flares in a confined space, and I also find it's easy to screw up the flare and have to do it over.



Rick B.