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Upgrading the Fuel Lines, Return PR and combatting Vapor Lock *mini project thread*

1083 Views 27 Replies 7 Participants Last post by  snolan
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As some may have seen my first initial thread I asked for opinions on AN fittings and line and you all were gracious to provide input. After some deliberation and research I did end up going with Racetronix for fittings and PTFE hose and "The Stop Shop" for my NICOPP hard line sections.

The purpose of this thread is to document my journey of creating a better routed fuel line system and to optimize routing and combat heat and potential of vapor lock issues I was having, mainly to have a Carb system that will sustain prolonged heat and consistent fuel needs during my first Hot Rod Power tour this year.

As typical when doing a major upgrade my intent is to maximize potential future application, hence being able to eventually go EFI with little to no effort when the time comes.

After a lot of YouTube-ing and reading online (here too) I determined the bets course was installing a fuel pressure regulator with return, larger return line than supply, and a " cool carb" cooling plate for under the carb (I have no room for a spacer).

As I'm predicting this to be very successful as it's been proven many times before I thought I would share my install and upgrades with others here in case they could find benefit in it in any fashion.

I can provide my extensive lost of parts involved if it becomes truly desired. I can estimate at current prices my investment thus far is approaching the $7-800 mark. (For those that need context from my past thread I was trying to get the most value in product of fittings and hose without spending outrageous money... obviously this is a substantial investment for optimal improvement). Having said that this same concept of improve CAN OBVUOUSLY be done MUCH cheaper with different products, line, fittings, OEM parts, etc. All in all this is my one car that I intend on keeping for a VERY long time and I like performance parts that make sense. I'm not going full on RACE but I do understand the benefits can be had for the application.

So let me start here...

First couple weeks included the mounting of the pressure regulator and the under the engine bay line routing which included new fittings for the mechanical fuel pump, new EARLs adjustable fuel log and return style pressure regulator. These a routed with intention to stay away and provide distance from main heat sources, Head, Lower coolant hose, headers and heater hoses.

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Shoutout to @novabob64 for the idea and concept of taking the lines through bulkheads on the inner fender and back from the inner wheel well to run directly down the side (more to come)

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So please feel free to follow along and support with comments or insights if you have done something similar and have had success or challenges the same.
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Just to add a little foresight if you ever notice your gauge reading differently than where you originally said it liquid-filled gauges are notorious for reading wrong when they get hot. I dealt with this last year on a car back and forth back and forth back and forth aero motive was actually super helpful in helping me figure it out. I used thier liquid filled gauge that is made by autometer and is supposed to correct all of these problems. Well it didn't. I thought for sure I was having fuel pump issues and didn't want to drop the tank. I put a second plain Jane non-liquid-filled gauge in and learned that my fuel pressure was rock solid when the expensive gauge told me it wasn't. Not saying you will have the same issue just thought I'd give you the mental note. Looks good!
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Thanks for the information, I'll follow this thread closely. I'm in the process of figuring out how to do the fuel system on my 64 nova (complete rebuild). I have a professionally built 400sbc with a 750cfm carburetor (dyno'd at 525hp and 528 lf-ft torque). I too, have decided to go with NICOPP hard lines between the external fuel pump and the carburetor and to use a return line to minimize vapor lock.
Just curious: Are you modifying your gas tank to match your upgrades? Or replacing it? I need to replace my tank, so I'm on the fence whether to use an aftermarket fuel cell ($) or take the plunge on a custom built tank (Rick's Tanks $$$). Thanks!
Gamparano are you using a mechanical pump?
No, I'm using a Holley 12-600 electric external pump which the engine builder recommended.
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Currently I'm setup with a mechanical fuel pump for main use/supply, I do have a Carter low pressure vayne style pump inline for backup as needed and assists in filling the fuel bowls when drained down or the mechanical fails. Appreciate the input on the gauge, I would hope my Moon gauge is accurate as it is really fairly new.

The NICOPP line on my setup will be running the length of the doors basically from wheel well to wheel well and the remainder is all stainless braided AN.

As far as the tank I'm running stock, I'm adding a rivet nut style 8AN port for the return.

For todays update from last night the the power feed wire was relocated (for the electric backup pump) was relocated to make room for the new NICOPP lines and the AN line were made from bulkhead to bulkhead in the front wheels well. (see image).

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We started bending the 1/2 inch NICOPP return line by hand but got to a stopping point. I'm sure next update will have some images to include of the hardline (NICOPP) routing/mounting.

Thanks again for tagging along and commenting!
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For those following along and for @gamparano we did get a little time last night to pull the tank and drill for the return bung (rivnut port 8AN bought from CPP). We drilled, crush fit, and water flushed the tank with 3 rinses to remove shavings. Keeping it on a flat side plane and away from the pickup should prevent a decent amount of return fuel frothing and air percolation.

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There are multiple vendors making these now. But CPP had the best price point and in 8AN where most are only making 6AN. I believe the others include FITech, FAST, Jegs, etc. search fuel return line fitting.

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@mc1984ss

45137 EZ Return Fitting -8AN to 3/4 in.-16 O-ring
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UPDATE FOR THIS WEEK:

Tried to start hard lines towards the end of last week, really determined that the right tools would be required (1/2 inch tubing bender) more $, but WAY better to have the right tool to do the job the RIGHT way.

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Started by practicing and making a basic form for the areas with the most bends and transitions of the lines. This proved to be beneficial for making the final line to replicate the practice form angles and slopes desired. This attack of doing the larger return line first allowed to plan the best way to route the smaller line which is more malleable and keep the bends less aggressive on the return which is desired since the fuel will be at a lower pressure in return and gravity/flow restrictions are helpful.

Over the last 2 evenings of work this week we were able to layout, replicate forms, and mount the final hardlines from the AN bulk heads back down the inner pinch welds as desired and place bends to start rerouting into PTFE under the subframe connectors and transition over axle/ rear frame rail headed to the tank and low pressure electric pump connections.
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Stand by for mor to come, gotta wrap this soon as we're approaching the 1 month countdown to leave for Power Tour (and there is more on the prep list).
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I've done a fair amount big hardlines and can appreciate your work, nice job!!!! What bender did you end up buying?
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I've done a fair amount big hardlines and can appreciate your work, nice job!!!! What bender did you end up buying?
Rigid actually from Home depot shipped to home. Link. Also bought another from amazon specific for 3/8 tubing. All of the 1/2 inch ones on Amazon did not support annealed/copper tubing.
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UPDATE: Well, I feel like we're getting close to done, this week:

Tank remounted with strap liners in place, built/measured rear PTFE lines, drilled and mounted with cushion P-clamps, adapted to hardlines with AN fittings, etc.

As of last night the full system was in place and all fittings were tightened, compressed and set. Next time the system will be refilled, primed with fuel and assessed for any leaks then checking and setting for optimal fuel pressure via the regulator. We will be installing the COOL CARB plate and making some adjustments to the primary jets before fire up.

Enjoy back half pics with final connections!

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UPDATE: Well, I feel like we're getting close to done, this week:

Tank remounted with strap liners in place, built/measured rear PTFE lines, drilled and mounted with cushion P-clamps, adapted to hardlines with AN fittings, etc.

As of last night the full system was in place and all fittings were tightened, compressed and set. Next time the system will be refilled, primed with fuel and assessed for any leaks then checking and setting for optimal fuel pressure via the regulator. We will be installing the COOL CARB plate and making some adjustments to the primary jets before fire up.

Enjoy back half pics with final connections!

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Awesome! One word of caution, I would separate any current-carrying wire/cable from contact directly with any fuel lines and provide chafing protection where cables are connected so you don't end up buffing off the insulation and burning down your awesome new ride. I've had it happen personally and lost a built 62 burned to the ground back in the 80's... Unrepairable after that.
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Awesome! One word of caution, I would separate any current-carrying wire/cable from contact directly with any fuel lines and provide chafing protection where cables are connected so you don't end up buffing off the insulation and burning down your awesome new ride. I've had it happen personally and lost a built 62 burned to the ground back in the 80's... Unrepairable after that.
I guess I should have clarified those... the wire ties are temporary at the moment. If you look back at the other images this wire IS and will be p-clamped separately (we just didn't get to it last night), but good catch. Luckily we are smarter than that and really just wanted the wire from drooping for the pictures as Pops knew I wanted to post update pictures.
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I guess I should have clarified those... the wire ties are temporary at the moment. If you look back at the other images this wire IS and will be p-clamped separately (we just didn't get to it last night), but good catch. Luckily we are smarter than that and really just wanted the wire from drooping for the pictures as Pops knew I wanted to post update pictures.
Awesome! Sorry, my eyeballz always lookin' for trouble. That's what I do all day for the last 35+ years. Glad you and pops are on it!! Can't wait to see the final product doing burnouts!!! :)
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So after some more slightly expensive lessons in fittings and application for making bends work with proper swivel fittings. Also lessons in cutting back nylon braid and sheathing for proper olive crimp sealing, resulting in remaking a few lines to fit correctly. So far the results are working weel as a bench test after lessons learned combatting 3 different areas of fuel leaks. Operationally current NO LEAKS as sitting on jack stands still. Road test should be soon. Oh check out the added HARD LINE PROTECTION PLATE.

@Stroker Ace Ventura no more wire ties!







We also installed this plate from COOL Carb which is a plastic composite sandwiched between aluminum to reduce heat soak in the carb and bowls.



I'll let everyone know after some hot runs here soon as we will be testing the cooling system....

IT'S CRUNCH TIME PREPPING FOR POWER TOUR!!!!
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So after some more slightly expensive lessons in fittings and application for making bends work with proper swivel fittings. Also lessons in cutting back nylon braid and sheathing for proper olive crimp sealing, resulting in remaking a few lines to fit correctly. So far the results are working weel as a bench test after lessons learned combatting 3 different areas of fuel leaks. Operationally current NO LEAKS as sitting on jack stands still. Road test should be soon. Oh check out the added HARD LINE PROTECTION PLATE.

@Stroker Ace Ventura no more wire ties!
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We also installed this plate from COOL Carb which is a plastic composite sandwiched between aluminum to reduce heat soak in the carb and bowls.

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I'll let everyone know after some hot runs here soon as we will be testing the cooling system....

IT'S CRUNCH TIME PREPPING FOR POWER TOUR!!!!
Looks GREAT! Love that shield too!! I have a few (LOL... more than a few) old street signs procured by someone and someone else... LOL... :p Good for a lot of things automotive for sure!!
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I think that shield is good for another 10hp on the top end
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I think that shield is good for another 10hp on the top end
And maybe some protection on the bottom end too! :p
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