Two line A/C cars.... What are you guys doing on your A/C cars With the RobbMC fuel or any Single line pump? https://www.v8buick.com/index.php?threads/robbmc-pump-fuel-line-issue-solved.377191/ This look GREAT.... I now Bob or Me don't have A/C in our cars. They are single line cars.. Im fine with that...I just started to put the return line in. Should just ditch the second line Idea? Looks like I don't need it....
. I believe the instructions tell you there is a metered port on the bottom of the pump. https://www.robbmcperformance.com/instructions/Buick550pump.pdf
I don't see a return port on the pump..... Just 1 in port & 1 out port. I'll admit I don't have a pump in my hand so there could be a 3rd port....
I think on the first gen pumps, you teed into the line to the carb from the pump. It reduced the pressure a bit from 8 psi. Now I see he added a metered port on the bottom.
Just the info I needed. Another question: Would you need a fuel pressure regulator for a Quadrajet (Edelbrock 1910) if you use the vapor return line?
It depends on the year of Q-jet you have. Later Q-jets had a much stronger float assembly. My 1972 7042240 regularly deals with 8-9 psi from my CV Products pump. I have even seen 10 psi on my gauge. The carburetor never misses a beat. Early Q-jets could only deal with 6 psi max. The Edelbrock 1910 should be fine.
One of the bigger ones I think. Jim Weise did it for me 11 years ago. The carburetor is seamless everywhere. Ran 11.60's with it at Cecil years ago.
As long as you do not have a float that's partially bad ( a tad soggy) 8 to 8.5 psi is fine. It was only the 1967 Q-jet that had the low leverage inlet system. They quickly found out how bad it was by Aug of 67 .
What size return line would you guys suggest of I use the metered port of the robbmc pump and a 1/2 inch feed line.
I’m using a RobbMc pump on my 350 I have his 1/2” pick up and 1/2” line to the pump and utilizing the factory return line
Exact same setup on my GS. RobbMC states this setup is good to 550 HP. And, he can modify the pump to work up to 750.
What material do you use for the feed line? I was about to get braided Teflon line as those won't smell
I used 3000 p.s.i. 1/2 in. I.D. fuel hose with 8AN Push Lok fittings at all connections. I chose Push Lok as they are way easier to install and they will handle any pressure our cars operate at, including fuel injection. I also installed one of RobbMC 100 micron filters in the line under the driver's door secured with 8AN fittings at both ends.
