I just finished replacing my back-half fuel lines. It's nice to not smell raw fuel anymore, but it made me wonder, at what point is it advisable to move up from 5/16 feed and 1/4 return to something larger, and how much larger should that be? I have a stock Mark VII pump, and I plan to move up to a 255lp/h at some point, but right now I just have too many irons in the fire for that.
Well we use 3/8 feed with engines that produce 1000HP. Other than that i think a 5/16 line is sufficient for well in to the 600HP range or better. Example if i may!! All big block and HO small block Chevies came from the factory with 3/8 feed fuel lines. All 2 BBL and low performance small blocks came with 5/16. But with fuel pressures in the 40+ psi numbers a 5/16 line can support just about any HP you throw at it. Just me could be wrong.
Note we do not run 2 line EFI systems in our builds. I use a single line feed only. 2 Line systems are antiquated and obsolete. Foe you should know that. You are a ford tech in a dealer???
:hick::burnout::hick::mullet:
But if your existing system isn't returnless, and you do not plan to go over X power level...?
But as Tom mentioned....there's a lot of 500 horse Fox 5.0-based cars with stock fuel lines. What are YOUR ultimate goals?
My ultimate goals won't take me THAT far. I'm looking for 425, tops. Above that, N/A, driveability starts to take a dive., And Tom, I know that return systems are outmoded, but it doesn't bother me enough to adapt it to an internally regulated returnless fuel pump module. I don't care much for the idea of putting a FPDM on my car so that it can rot off and kill the engine, either. Between internal regulated and electronically regulated, neither sounds like a project I'm up for at this point. Like I said, too many other irons in the fire. I've got exhaust to finish, and a 5-lug/brake/suspension upgrade in line ahead of any more fuel system work.
Dont have to just use a Corvette fuel filter!!!!!
For 425hp or so you'll be fine with the stock lines. Like Tom said unless you're getting really crazy you'll be fine.
Or I could use a 2000-2004 Explorer fuel filter, but the fuel pressure is higher than what I have now.
Or I could use a 2000-2004 Explorer fuel filter, but the fuel pressure is higher than what I have now.
I might be wrong here but what is Fords pressure stats on this engine? Without research my gut feeling it is close to what you need. Will check that for accuracy?? So basically you know what i am talking about!! So with all the mods on this forum no one has researched or should i say used a single line setup. OK!!
We use the Corvette filter or the BMW unit that has a built in regulator that produces the correct psi as needed for a FORD. Try it you will like it!! The BMW filter is dead nuts at 42 LBS with no vacuum !!!!!!!!!!!
When I get to the point where I'm looking for my next mod, I'll keep that in mind.
It varies all over the net saying that stock lines and rails are good from 500 to 600 hp. I found the following on Kenny Bell's site and I would say trust him more than internet folklore.
http://www.kennebell.net/KBWebsite/Tech_Articless_pg/links/tech_articles/FUELPUMP.pdf
Darren
Checked into it. We have one apart right now, and 2000-2004 Explorer has a 2 in 1 out filter that returns fuel back to the tank, but the actual regulator is inline with the return, just inside the pump carrier assembly. Easy to make the mod, but I'm still wondering why I should. Our driveability tech pointed out to me that a returning fuel system supplies cooler fuel in the summer.
thats interesting, the cooler fuel concept.
wonder why the regulator is inline with the return plumbing.
if your dead set on upgrading, just go stainless and never worry again. the pfte type line is also durable and easier to work with though.
The regulator is always on the return side, check your rails. In the Explorer, excess pressure is allowed through the return, and it's in the tank because it's safer there.
Got it Aerocoupe you did not read my post very well. By the way it also depends on how many injectors the engine has. I support well over 600Hp with my 4.3 on a 5/16 feed and 1/4 inch return.
Guess us internet folk are just wasting time telling story's. Dam i have to have that dyno checked.
Better clear this up. A 2 line system is better for high HP applications. The single line system works great but dyno tests have proved that the dual system is a bit better. But remember you have a lot of wasted movement with a 2 line system compared to a single. Single systems can support tuns of HP but i think a 2 line system is best on engines over a set HP factor. The 650HP chevys use a single system. Cooling is not an issue.
Foe you tech is not correct in his cooling statement. If so why are all new cars single line??
Evaporative emissions. That's Ford's line on it, at least as far as I can remember. I think there was something about crash standards as it relates to the possibility of a fuel leak also. I haven't had to think about it since school.
At any rate, that's not what this thread was for. I feel better about staying with stock line sizes, so thanks everyone for your help.