Holley 4160 390 cfm
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5th Wheeling
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From: Earth
Holley 4160 390 cfm
I finally did it! Installed an Offy intake, Pacer Headers, and a Holley 4160 carb on my '83 4x4 F-150 Flareside (Old Blue). Gawg Dang!!!! Old Blue runs like the wind now. The engine performance and accelerator response is dramatic. I should have done this when I bought the truck 20 years ago! The difference is like night and day!
However, the carb needs some fine tuning and minor adjustments. I have a 4-speed w/granny tranny so I take off in 2nd gear. After I accelerate and shift to 3rd, I have a slight hesitation but then it comes out of it ok. The same thing occurs after I shift to 4th. Once I get on the highway, Old Blue runs GREAT! I'm just a little concerned about the hesitation when shifting gears.
Another concern of mine is the intake manifold vaccuum now reads 15 hg (steady) with the new Offy intake. With the old intake manifold it read 18 hg. Is this normal? I've got good engine oil pressure and compression. No vaccuum leaks detected. Could it be my air/fuel mixture needs adjusting?
If anyone could advise me as to correcting these problem I'd be most grateful.
jerrycarl...Springfield, Missouri
However, the carb needs some fine tuning and minor adjustments. I have a 4-speed w/granny tranny so I take off in 2nd gear. After I accelerate and shift to 3rd, I have a slight hesitation but then it comes out of it ok. The same thing occurs after I shift to 4th. Once I get on the highway, Old Blue runs GREAT! I'm just a little concerned about the hesitation when shifting gears.
Another concern of mine is the intake manifold vaccuum now reads 15 hg (steady) with the new Offy intake. With the old intake manifold it read 18 hg. Is this normal? I've got good engine oil pressure and compression. No vaccuum leaks detected. Could it be my air/fuel mixture needs adjusting?
If anyone could advise me as to correcting these problem I'd be most grateful.
jerrycarl...Springfield, Missouri
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From: Alaska
Holley 4160 390 cfm
I'm not really up on Holley's but one thing you could try on the hesitation problem is adjusting your accelerator pump if it's adjustable. It should be as simple as moving a rod to a different hole on the lever that actuates the pump. Give it a little more fuel and try it. If that doesn't work move it back the other way, if that doesn't work put it back where it was and maybe someone else can help you. My Edelbrock is nice and easy to work on and they make a nice little kit for tuning the carb with springs, jets, needles, etc....
As far as the vacuum goes I'm not sure what to tell you but your engine rpm and timing will affect that. My vacuum gauge came with a nice little instruction sheet that goes through the different tests and instructions on how to set things. I believe they want you to check vacuum at about 200 rpm above idle speed.
When I put my Edelbrock cam kit, performer manifold, and Carb on, my vacuum dropped also, but I think that was to be expected.
Hope this helps a bit,
Bruce
As far as the vacuum goes I'm not sure what to tell you but your engine rpm and timing will affect that. My vacuum gauge came with a nice little instruction sheet that goes through the different tests and instructions on how to set things. I believe they want you to check vacuum at about 200 rpm above idle speed.
When I put my Edelbrock cam kit, performer manifold, and Carb on, my vacuum dropped also, but I think that was to be expected.
Hope this helps a bit,
Bruce
Last edited by 83 F350; May 8, 2003 at 01:49 AM.
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Holley 4160 390 cfm
I always wanted to do that to my '81 F-150. Every time I'd get a new JC Whitney catalog I'd look at that setup and wonder..... get rid of the single barrel...... I never used 1st gear either.
But the windshield started leaking, I bought my wife a new car and the driveway was cluttered, and either the truck or my '75 Ranchero had to go. I sold the truck, kept the Ranchero for a few more years, and traded that in on a 2001 F-150.
If you are close to sea level the air/fuel mixture should be pretty good. If I remember, Holleys have a plastic cam that controls how fast the accelerator pump comes in. This isn't an expensive part, so you could buy an assortment and experiment.
But the windshield started leaking, I bought my wife a new car and the driveway was cluttered, and either the truck or my '75 Ranchero had to go. I sold the truck, kept the Ranchero for a few more years, and traded that in on a 2001 F-150.
If you are close to sea level the air/fuel mixture should be pretty good. If I remember, Holleys have a plastic cam that controls how fast the accelerator pump comes in. This isn't an expensive part, so you could buy an assortment and experiment.
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5th Wheeling
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From: Earth
Holley 4160 390 cfm
The engine is a 300 inline-6 that was overhauled about 20,000 miles ago. The Holley 390 carb and Offy intake were purchased new through Summit. Great company to deal with!
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Holley 4160 390 cfm
Get it warmed up, and while it's running, pull the site plugs out of the side of the fuel bowels(passenger side). The fuel should be a little below the hole. I like to set it where the fuel will just slosh out a little if I rock the fender of the truck. Set both front and rear. If the rear is too high, you might have to set it low and then drive it awhile. It takes a long time for the rear to use fuel, so it's best to start low and work your way up.
Then set the idle mixture screws. Turn them clockwise till the engine slows and runs rough, then turn them out till it just smooths out. Go back and forth and do each side a couple of times. You may have to adjust your idle speed at this time also. When your done, turn each screw counterclockwise another quarter turn. If you still have hesitation, turn the screws another 1/4 turn counterclockwise and see if it helps.
Clockwise=lean the idle mixture
Counterclockwise=richen the idle mixture
Then set the idle mixture screws. Turn them clockwise till the engine slows and runs rough, then turn them out till it just smooths out. Go back and forth and do each side a couple of times. You may have to adjust your idle speed at this time also. When your done, turn each screw counterclockwise another quarter turn. If you still have hesitation, turn the screws another 1/4 turn counterclockwise and see if it helps.
Clockwise=lean the idle mixture
Counterclockwise=richen the idle mixture
Last edited by Franklin2; May 12, 2003 at 10:11 PM.
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5th Wheeling
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From: Earth
Holley 4160 390 cfm
Dave.....Thanks for the advice. You were right, when I richened the idle mixture screws the idle smoothed out and the intake manifold vacuum increased from 16 hg to 18 hg. The hesitation is almost gone. Another 1/4 turn counterclockwise (richen) might just do the trick. Another question.....the instructions that came with the carburetor said there were 4 idle mixture screws but I can only find 2. Are there also idle mixture screws for the secondaries that need to be adjusted? If there is I sure as heck can't find them. Do you think I need to adjust the accelerator pump too? The electric choke will take some getting used to. I may opt for a manual choke in the near future.
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