Posted by Mavman (IP: 24.27.31.182) on June 03, 2000 at 10:51:54:
In Reply to: Re: Holley jetting posted by rickyracer on June 03, 2000 at 00:11:06:
: I suppose you're talking about a 600CFM vac. secondary size, jetting should be around 62 in the primaries, but also make sure your choke butterfly is also open all the way, If the jets that are in it now are around 64 drop them down to 58 and drive it for about 200 miles and check the plugs again. after that only drop them about 2 numbers at a time. Also make sure the floats are set proper or it may be floading out from the floats already, Check the floats and choke valve before you play with the jets.
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: : I need a base line on what jets to use in a 1850 holley. I bought it used off of a 383 Chevy motor so I think it is jetted to big for my mild 289. Can anyone give me a place to start. I know nothing about carbs or tuning. The plugs are black and wet. The engine has about 50 miles on it since the rebuild. It also quit running twice today once like it was running out of fuel(while driving at speed), and the other as I was pulling out from a stop. Too much fuel? Any help would be great thanks in advance. Russ
Invest in some clear site plugs. Cost about $5 and help alot. How fast does it idle? There is a set screw under the vacuum secondary. It faces the intake. You may wanna check the secondary gap with a feeler gauge and check the tolerance. Unfortunately, I don't know what that tolerance is. I do know that if you can't idle the motor down, as in when you screw the idle screw out and the idle only drops so far, then the secondaries are staying open for some reason. This would also make it use more fuel. Good responce, but more fuel.
Depending on what you are going to do with this 289( I also have one), you might consider a quick change secondary spring kit and a spring kit. It does just what it says. Quick change. This will allow you to adjust the opening time of the secondaries.
I am currently using 66 jets in my 80457S 600 Holley. It's the electric choke version of what you have. I changed the accelerator cam to the big blue, then adjusted the accelerator pump spring to give the longest shot I could without bottoming the spring. There has to be some spring play. Also running a 35 shooter. Stock was a 31.
One of the biggest gains that I had was due to a 1 inch plastic spacer under the carb. This makes the plenum longer, and isolates the carb from the direct heat transfer from the intake. It keeps the fuel from boiling.
Three last things...get a Mr. Gasket high flow 160 degree thermostat, and if you can find one, get a four row radiator. Might have to get one built. Either that or put an aluminum radiator in it. A good electronic ignition and you are set.
Hope some of this helps. Of course, if someone wants to add/disagree, I'd be happy for the extra info!!!