EFI conversion question
Race Director
Joined: Sep 1999
Posts: 11,361
Likes: 383
From: Plano TX
Tank to supply line, ~1 foot.
Supply line from frame to engine ~6"
FP regulator (on engine) to return line (on firewall), ~6"
Return line to tank, ~1 foot.
Melting Slicks
Joined: Jun 2016
Posts: 2,979
Likes: 332
From: Woodinville WA
Yes, the factory 3/8" steel line can be used as either supply or return. You still need to add a second line. Some use the 1/4" vapor line as return which may or may not work. I used 3/8" steel brake lines for my return. I also prefer to keep the rubber hose sections as short as possible. The rubber hoses I have are:
Tank to supply line, ~1 foot.
Supply line from frame to engine ~6"
FP regulator (on engine) to return line (on firewall), ~6"
Return line to tank, ~1 foot.
Tank to supply line, ~1 foot.
Supply line from frame to engine ~6"
FP regulator (on engine) to return line (on firewall), ~6"
Return line to tank, ~1 foot.
Wait... are you sure?!?
Up to how many HP can you still use the 3/8" factory steel line?
My fuel system is the last part of my EFI conversion I still need to deal with; I've been avoiding it because it was just mind-meltingly complex for me and I wanted to try to understand it in chunks.
My factory steel line stops up basically just in front of the starter on the passenger side and then transitions to a section of rubber hose, then goes back to steel for a little bit, and then rubber to steel at the carb (the line to the carb got cut decades ago and replaced with rubber and hose clamps....). -If I kept the steel line up to that same spot near the starter how would I transition to a high pressure EFI hose the rest of the way to the regulator?
Adam
Race Director
Joined: Sep 1999
Posts: 11,361
Likes: 383
From: Plano TX
Haha, been running it this way for 15 years.
At least 600 hp. My 454 was blowing black smoke when I had the EFI set too fat so the 3/8" line was enough to overfuel it no problem.
A simple barb fitting on the regulator side and the factory line already has a barb on it that is sufficient. Use EFI-style clamps. You can get 1 ft EFI hose at auto parts stores. Additional plus is it's ethanol compatible.
EFI hose clamp (notice it doesn't have the worm clamp slots which would cut into the hose):
Up to how many HP can you still use the 3/8" factory steel line?
-If I kept the steel line up to that same spot near the starter how would I transition to a high pressure EFI hose the rest of the way to the regulator?
EFI hose clamp (notice it doesn't have the worm clamp slots which would cut into the hose):
Last edited by zwede; Dec 11, 2017 at 05:15 PM.
Drifting
Joined: Jul 2012
Posts: 1,255
Likes: 297
From: Slovenia, EU
2017 C3 of Year Finalist
Well, my Holley rep here in Sweden told me that i should keep me MSD dist as it is with vac advance, i wont gain anything by letting the Sniper control timing....lots of issus with MSD and controlled timing...and only way to get it fixed is to buy the Holley sync dist and thats expensive!
I'm from Europe also and am looking at the possibility of going EFI.
Intermediate
Joined: May 2017
Posts: 45
Likes: 5
From: Napa Ca.
Gooseneck?
Where did you get the gooseneck in the picture with the Sniper temp sensor installed? does it work OK installed there? In the instructions it told to install in the manifold or the block. Thank you.
Race Director
Joined: Apr 2007
Posts: 11,152
Likes: 890
From: South Western Ontario
CTS should go in the coolant before the thermostat, not after. It would work, but the cold start to hot running fuel transition will not be correct. If you need a spot then get a spacer block that goes under the thermostat with a hole in the side for the sensor.
Melting Slicks
Joined: May 2012
Posts: 2,192
Likes: 343
From: Allenton Wisconsin
While doing the Sniper conversion on the 69 which has a BTO 200r4 tranny the TV calbe hook-up to the throttle linkage is an in house modification at BTO. $165 for modification and $49 for insured shipping. T
Thread Starter
Racer
Joined: Jun 2015
Posts: 315
Likes: 20
From: Vasteras, Sweden
Corvette Stories
The Best of Corvette for Corvette Enthusiasts
Top 10 Most Expensive Corvettes Ever Sold on Bring A Trailer
Brett Foote
10 Things Every Corvette Owner Needs (2026 Edition)
Michael S. Palmer
8 Most "Only Corvette Owners Understand" Quirks and Problems
Pouria Savadkouei
10 Reasons the C6 Z06 is Still A Performance Benchmark After 20 Years
Joe Kucinski
How Much Horsepower Every Corvette Engine "LOST" in 1972
Joe Kucinski
Top 10 DOs and DON'Ts for Protecting Your Convertible Top!
Michael S. Palmer
Top 10 Most Explosive Corvettes Ever Made: Power-to-Weight Ratio Ranked!
Joe Kucinski
150 hp to 1,250 hp: Every Corvette Generation Compared by the Specs That Matter
Joe Kucinski
8 Coolest Corvette Pace Cars (and Replicas) of All Time
Verdad Gallardo
Thread Starter
Racer
Joined: Jun 2015
Posts: 315
Likes: 20
From: Vasteras, Sweden
That sensor is for OEM temp gauge, Sniper sensor is in one of the heads.
Advanced
Joined: Jun 2017
Posts: 61
Likes: 2
From: minneapolis mn
it looks like you used the old supply line on the bottom of the tank to connect to the inline pump. where and how did you connect the return line (the old steel supply line) to the tank? i ask because my 66 convertible only has that one supply pipe at the bottom of the tank.
