ajrothm

I decided to do a build thread in hopes that it may provide some info/tips for members in the future that need to update their fuel system for some serious power. I searched the forum looking for info/pics and there wasn't really much out there at all so, I just designed my own.

To start out, I have been running my car for 8 years with a trusty Carter 172 race mechanical fuel pump, which is plenty of pump, WHEN you have it plumbed properly with a -10 inlet, which is impossible in a vette frame. So I had it necked down with a tight radius ORB fitting which was -6an. Here is what it has and what its supposed to have.



I always had a huge fuel pressure drop, however the AFR seemed to maintain plenty rich through the traps so I just let it ride until recently, when it started nosing over during some races...as seen here...

So I finally decided to redo everything and do it right this time. With no real mechanical pump options available that would support it, and be reliable without rebuilding every 60 hrs, I decided to go electric. I wanted to overkill this system to make sure I have enough fuel for my future BIG motor and/or nitrous. Here was my plan.

Holley 12-1600 Dominator twin fuel pump... 155 gph @8 psi
-10 an feed, -8 an return
Bypass style regulator
FP gauge and pressure transducer so I can log fuel pressure.



The parts:


Robb MC 1/2" pick up



Here is the mounting bracket I made using the factory gas tank bracket.


Assembled....



Now for the system install, at this point, all of you NCRS/Purist types should probably close your eyes, because this is gonna hurt your soul.

I wanted to run the -10 feed and -8 return in the factory line locations, so this required removing the factory lines to gain some room....Ofcourse, cutting was involved...


And running lines...






Yes I drilled some holes....






I hid the regulator WAY up in the fender...inconspicuous..



Barely noticeable..


A single -8 feed to the carb...nice, simple and not blocking anything or coming over the valve cover etc...



All plumbed up in the rear...


I still have room for the spare tire carrier, well at least the bottom section so I can use it to carry tools/supplies on road trips.

My plan is to run on one pump with a key on source like a regular car, then have the second pump on a toggle switch for an emergency back up, or have the pump come on with a nitrous kit down the road. This should minimize fuel heating and vapor locking etc on long drives.

Its all installed, I just need to do all of the wiring this week, then leak test the system. Hopefully running again by next weekend and get some revenge...



I hope this helps someone who is trying to figure out how to mount/plumb a system in a C2/C3....

ddawson

That looks great.

427Hotrod

Nothing to it right??? LOL! Great job!

JIM

ajrothm

LOL... Yeah right... 3 solid days into it at this point, and still haven't started the wiring.

I'm trying to figure out the best way to hide the relays and minimize wire runs... Gonna plan it this week.

Les

LOL at the advice for the NCRS folks. Great write up. That looks real clean so far Alan. I'm sure you'll finish it in the same manner. Then I pity the Mustang that tries you on.

427Hotrod

My relays are inside the car at the back of the storage compartment behind the carpet where it goes upward. I wanted them as close to pumps as possible. I ran the wires down to the pumps through grommets.

JIM

ajrothm

That's a good idea.

I thought about putting the relays in the battery compartment, then just running the 12v to the pumps, but my battery compartment is already full of wires/fuses and stuff.

I'm gonna look at it this week and see what I come up with. I need it running by Friday... I have some rematches lined up..

chevymans 77

Thanks for posting, looks like a solid fuel system,

I've got all the parts for my upgrade except the fuel hose, trying to figure out how to protect the hose when it crosses the half shafts. Thinking of mounting some EMT tubbing over the shafts and running the hose through it along with the straight sections along the frame. I ended up going with the Mallory 250 pump and matching regulator along with -10 hose.

I like the dual pump you used, like you mentioned if one fails you have another mounted and ready.

I also have nitrous in my plans for this engine before moving to the next engine build.

Neal

cv67

some good information thanks for posting

also running a carter 172 with 1/2 to the pickup..how much life are you getting out of them & are rebuild kits still around? No regulator I assume?

Keep us posted (nice clips too!)

71VetteLover

I ran my pressure line from my Carter 100 gph electric fuel pump all the way to my #3310 Holley and then sent the return line from there back to my tank. The return line is 5/16" and it's just the right amount of restriction to provide 6 psi without the need for a pressure regulator. The continuous flow past my Holley ensures the fuel stays as cool as possible. Note that I also included a pressure tap.

Richard454

NICE work-

Only thing I would add is one of these-

Fuel roll-over -impact/inertia shut off

Ford used them through the early 2000's-Mustang /Taurus lots of them out there- very reliable and can even buy them Brand new from Summit for about $30.

Just use it to break contact w/ the ignition switch to the relay. Normally closed circuit- opens when rolled or sees impact.




I'm running the Fuel pump relay and inertia switch in the back compartment-


Too much stuff in your storage compartments? I went with twin 6V batteries wired in a series and got a bunch more room.

v2racing

I'll be putting my fuel system together soon. I have a Mallory 140 GPH pump. I welded a sump on my tank and will feed the pump with a -10 AN line with a 100 micron stainless filter in between. I'll go -8 up to the regulator at the engine with a 5 micron filter. It will have 2 -6 lines coming out to feed each bowl and a -6 return. The pressure up to the regulator will be 15 lbs regulated down to 5.5 lbs. I have .140" needles, so it won't need high pressure at the carb.

Mike

69ttop502

What are you running for lines Alan. Are those braided Teflon? Curious how easily they bend to fit. Going to need to do something similar on mine. Good stuff!

stingraymax

76strokervette

Once you get above 650 hp the factory lines will struggle to feed your engine.

ajrothm

Its just the Jegs brand Pro-Flo 350 braided hose, light weight. Its just nylon rubber and braided. Its supposed to be good for most fuels but doesn't specify E85 due to the different additives etc...(so they say)... Its not the PTFE lined hose.. I wasn't about to spend $400 for two 20' sections of hose for E85 capability when I'll never run it on this car.

This lightweight hose bends very easy, pretty resistant to kinking, you do have to watch for "twists" when tightening up non swivel type fittings.

I think it will be fine for a long time. If I have to change it in 10 years, no biggie....Its easy to change now that I know how to do it.

ajrothm

Nice tip on the switch. Pretty interesting.

I'll likely just run the pump relay through a key on source. If I crashed the car bad enough, I'd hope it burns up....LOL...

Where are you mounting your relays? I thought about the battery box, but its pretty tight in there. I don't want to be running wires front back and side to side in the car...LOL. I was thinking everything in the battery box, then just the two power wires to the pumps. Run a key on 12v to the battery box and ground it all at the battery.

I really don't want to drill any more holes then I have to...or I'll never get Topflighted.

ajrothm

No kits out there for a 172. I did find a kit for a carter 130 that a mustang resto shop sells for $60. Once I got it, it would "work" on the 172, but the spring was WAY smaller on the 130 kit. I didn't end up changing the diaphragm but changed everything else.

My 172 worked great for years, and still seems to, however all of the sudden its not keeping up at all. Maybe the diaphragm is just weak, I'm not sure. I'll hold onto it and use it on my other cars. Maybe my fuel pump rod tip is wore down and I'm not getting enough stroke on the pump, not sure, I can't get the rod out.

I ALMOST went with the Holley Ultra 200 billet mechanical pump, but it had some bad reviews and a 60 hr rebuild interval...and I wasn't about to fight with pulling this mechanical pump off every 60 hrs....Its an all day job.

Neil B

Looks great! I'm taking notes for my build.

BKbroiler

Hey that was a great video - in broad daylight no less. I noticed you raising & lowering widows. You didn't have the AC on did you?

Nice work on that fuel system too.