Hey,
Just ordered my 390 cfm holley for the 2.8. I am going to try running it with the 2 to 4 bbl adapter plate and will let you all know how that turns out. More as soon as it shows up.
Hello Squid78v6,
You really need the 4V manifold if you are going to reap the benifit from the BIG dolar carb you just bought.
I fear that disapointment is what you are about to achieve.
Remember weither you have purchased the 8007 or the 6297 you will have to rejet the carb.
Remember those equasions on the chalkboard that you said " when am I ever going to need that"?
Well now is that time!!!!!!
A cubic foot of air weighs .07 pounds.
A cubic inch of fuel weighs .026 pounds
"The short version."
Air/Fuel Ratio - The ratio of pounds of Air to pounds of Fuel needed for combustion in an engine. Air/Fuel ratio is based on pounds of AIR to pounds of FUEL but carbs are metered (jetted) by volume so changes in fuel can change A/F ratios. A/F Ratios range from about 2:1 for NitroMethane to about 16:1 for gasoline, with 14.7:1 considered the stoichiometric or chemically correct ratio under perfect conditions with normal (non-oxygenated) gasoline. Gasoline A/F ratios for best power tend to be in the 13.25:1 - 13.75:1 range.
Really to get into the technical terms is pointless as the varing atmospheric temperature changes so does the density of fuel and air so I give you a short cut.
Buy a set of # 50 jets for the primarys to start out with and then do some spark plug readings.
Master this!
This is called tuning.
Required reading.
http://www.eric-gorr.com/techarticles/fuel_terminology.htm
From Pintony
hey,
Thanks for the further info.
The story behind the adapter set up is that my stock 2150 carb was getting to be problematic and the previous owner of my car had hacked it up a bit so I needed to replace it. I had the delema of replacing it with another rebuilt 2r barrel or a rebuilt holley for about the same price. So I figured until I can afford to spend $300+ on the intake I would run the adapter. We will have to see how long it is before I can get my wife to ok an intake. I just hope there will be some inprovment with the stock intake. I didn't get the post about the #50 jets until after I tried to install the carb. Didn't get to find out if it ran or not because my starter went out before I could get the gas up to the carb. Any idea what jets would come in stock in one of those carbs?
Thanks for all the info and help, James
You may want to watch ebay for those 4bbl manifolds. The pop up from time to time and the highest I've seen one sell for was $125.
-Harry
Quote from: squidd78v6 on January 21, 2006, 11:12:14 PM
hey,
   Thanks for the further info.
  The story behind the adapter set up is that my stock 2150 carb was getting to be problematic and the previous owner of my car had hacked it up a bit so I needed to replace it. I had the delema of replacing it with another rebuilt 2r barrel or a rebuilt holley for about the same price. So I figured until I can afford to spend $300+ on the intake I would run the adapter. We will have to see how long it is before I can get my wife to ok an intake. I just hope there will be some inprovment with the stock intake. I didn't get the post about the #50 jets until after I tried to install the carb. Didn't get to find out if it ran or not because my starter went out before I could get the gas up to the carb. Any idea what jets would come in stock in one of those carbs?
Thanks for all the info and help, James
Hello Squid,
The factory 390 Holley came with #46 jets. on the primarys.
The secondarys are a plate they do not have jetting.
The primary problem with the holley is driveability.
The carb will act as if it is running too rich. Actually the cartb is starving the engine for fuel and it will start pulling gas from the mains to get enough fuel for the engine to run.
I usually start out with a 125 powervalve.
The factory setting rom a 390 will produce a CLEAR dead spot while driving.
A properly jetted 390 will run-out smooth throught the RPM range.
From Pintony
From Pintony