Hello I need some help, identifying some "Parts" on my holley carburator I need some help. I have recently bought my first "hobby" car. A 1970 Maverick. And I am slowly learning everything..... The maverick have a 289 V8 and a c-6 transmission. The Maverick is a very rare care here in Norway. So I guess I am very lucky this forum exists ! The 289 has an edelbrock intake manifold, and a holley carburetor. I do not know the type. I want to install a return type fuel system. However I need some help with identifying some "Hoses" I have marked them out in the attached picture 1: I believe that this is the return line. (Blocked by the prevous owner) ? For 2: and 3: I have no clue ! Thank you all in advance for taking the time !
find the numbers on the carb / to identify the carb then you will be able to find a diagram and it will tell you what all goes where and what cfm it is ///// and our cars came with 302's not a 260 and c4 trans not a c6 /// unless someone swaped them into it
First off, you don't need a return type fuel system with any Holley carb. Second, #1 in the pic is the nipple for the PCV system hose. #2 is the ported vacuum nipple for the distributor vacuum advance hose. #3 is full manifold vacuum, used for anything requiring that. The carb looks like a run of the mill Holley 600. There's a "list" number on the front of the choke horn. Most 600's are list 1850 (dash 1 thru 3) This list number is the number used in picking parts and kits for the carb.
Thanks for the advice, both of you ! This makes my life easier ! Why do I not need a return system ? I read the linked article, and ended up quite convinced that a I really needed a return system. But as I stated, I am a beginner, so I need every advice I can get ! http://www.centuryperformance.com/fuelish-tendencies-understanding-fuel-pressure-and-volume-spg-140.html Steffen
The article is talking about electric pumps that you use an external fuel pressure regulator with. 2 types of regulators. One has a return system and one is a dead head style regulator with no return. The return style regulates the pressure to your setting usually 5-7psi and the excess fuel is routed back to the tank. The dead head style has no return and regulates the pressure internally in the regulator. Unless you are running a high flow.pressure electric pump you wont need the regualator. That article is more directed to a race car than a street car. I got rid of my electric pump for a mechanical. Mechanical pumps are set at 5-7psi and do not require a regulator. If you add an electric pump you now have to plumb the fuel lines,install filter before pump.mount pump at fuel level under the car,make a harness with a relay, install a cut off switch in case of accident or stalling, install regulator under hood and plumb lines then hope its reliable. Cost here to do it myself is around 300 dollars and up depending on components. The mechanical pump on the side of the motor needs nothing but a running engine. Hope this helps.
That article is assuming that you're after all out racing performance. And the fuel requirement calculator is something for a rule of thumb, much like the calculations for carb sizing. Change the fuel mixture, atomization of the fuel and a couple other things, and it's possible to make that same HP with less fuel. I run a 35 gal/hr electric (Mr Gasket 12G) pump in my 77 Comet feeding three Holley 250's. It has almost NEVER failed to feed this setup at wide open throttle, even when I had it in my 89 Ranger. When it did, it was becasue the fuel filter was full and needed to be changed. With a clean filter, it's done the job at full power runs for several minutes (top end runs at 140 mph) If you think you need a return system, then you're running a pump that's too big to start with, if you've got it feeding a carb. Once again, the pump on a carbed system is only there to feed fuel into the bowls. The needle/seat inlet valves cease to function at about 7 psi and it will flood the bowls, spilling out the bowl vents into the throttle bores and sometimes outside the carb as well, creating a fire hazard. It takes very little flow to keep the bowls fed under 99% of circumstances. 30 gals per hour is enough to feed a motor that's getting 2 mpg at 60 miles per hour. And one that is doing that bad in fuel consumption, has got something drastically wrong with it.
