So I just picked up my new engine that Jim Weise built for me. Because of the horsepower, I need a different fuel pump. Reviewing info on the pump Jim recommended, I need to upgrade the fuel supply line to 1/2". Now that being said, I understand getting an electric pusher pump near the tank is an option that doesn't involve ripping out the 3/8's supply and replacing it with 1/2". So the question to the people smarter than me, can anyone recommend a fuel pump that will do the job?
What is your hp? I ran a Robb Mc mechanical on a 480hp engine without changing the 3/8” line. Try that first. Should be good up to 500 hp. If it’s necessary to upgrade to a 1/2” line(8an) leave your 3/8 line and return line intact and run the 8an up the drivers frame rail.
You're at the limit with 3/8 with a carb...if you're gonna go fuel injection your fine. Couple options actually....you can use a drop in module from Holley or just modify your stock pickup/sender to use an intake pump...then run a dual bypass reg from Aeromotive...little pricey but works well For a pusher pump location can be a problem...they need to be gravity fed and with a stock tank that's basically impossible....they will work in conjunction with the stock puller pump..but your limited to what it can flow and move...your just basically making sure it has a backwall of available fuel..which is good..but still a limit of what it can supply So to do it correctly and solve a couple other issues such as cooler fuel...more fuel....better performance and no chance of starvation...you need a sumped tank...OR go in tank and gain several benefits
What Carb are you running? Are you running a Holley ? Are you running a Holley blue type regulator? In general please note this about those deceiving blue regulators if your running a Holley with its two needle and seats. The flow area of the needle and set in those regulators is far less then the combined flow area of both needle and seats in the Carb! Basically if you look at it such that both needle and seats in the Carb are 100% volume then running a blue type regulator restricts that down to about 60% of what you need to keep the Carb satisfied. Sorry if I took this post off the rails a bit!
I ran the Holley Red pump for years, pushing through the stock Stage1 pump. I ran it with a relay and toggle switch under the dash. Occasionally, I found the car would nose over if I didn't have it on, and I was driving a bit aggressively. It does present a restriction to fuel flow when off. Another option is to wire the relay to the switched side of the kick down switch, so the pump comes on when you step on the gas. I mounted it to the front wall of the trunk, and teed it into the rubber line. https://www.holley.com/products/fue...carbureted_electric_fuel_pumps/parts/12-801-1
Wow, thanks for the replies guys. You've given me something to think about. I will be running a Rochester BTW.
Larry, do you have any pictures of how you had that pump mounted and plumbed? I've been thinking of this exact kind of set up..
No, I looked around and could not find any. It was mounted to the vertical wall of the trunk, very close to the rubber line that comes off the fuel sender. Just cut the rubber line and tee the pump in.
The 73 GS I just got has that setup. Up until now I did not know why it had the additional electric pump by the fuel tank. Darn thing is LOUD. I'll try an get a pic of the setup. Car is up in the air now so it's no big deal. I will say that starting to look into this, I'm leaning to getting an in-tank pump like a Holly Sniper.
I still use the mechanical pump that Jim Weise got for me. Jim put a Buick arm on it. It has never let me down going on 12 years now. It is easily rebuildable as well.
If you go with an electric, set it up on a bypass regulator not a dead head. Your pump will run so much cooler
Here are the pics of the pump setup on my GS. Hard to get a good pic but hopefully these will be useful. I will be using a mechanical pump, the electric one will be a booster at low pressure. For the mechanical pump Jim recommended https://www.robbmcperformance.com/products/buick550.html
I would go with the robbmc pump and not use an electric pump at all. That's what I run on my Skylark with 1/2" lines and my son's Regal with 3/8" lines. The Regal runs 11.40's at 120 with no fuel issues. He does have 1/2" lines and a robbmc sender/pick up here that we will install in the spring because of his future plans for the car. Ken
Mech pump is fine....IF you have the line needed...like I Saud you're at the limit with the 3/8....if you wanna upgrade the line fine....nothing is being done about fuel slosh tho....then yourr talking about sumps..baffles etc...
At 425hp I never had a fuel issue...at 525hp I had all kinds of fuel issues....you drive like an old lady...sure you may not experience fuel slosh...you use the power you spent your money on you will...simple physics
Think about where your pickup is.... 525hp with throw the nose up and keep it up...mech pump takes a big gulp of air instead of fuel during the time the fuel is away from or playing peek a boo withe pickup.....last I checked air doest burn
I'm not good at bending line, hence why I was asking about a booster pump. But just upgrading the line will be a lot cheaper than adding an electric fuel pump. Any good sources for 1/2" fuel line? Ideally in Nicopp as it is easy to bend. Inline tube has some but only in stainless.
