holley 750 tuning

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sbh126

sbh126

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I have a holley 4160 750 carb that I am going to run on my 440. Before I break in my motor I want to have it adjusted to run a little rich. I was planning on putting it on my 383 to get it adjusted so I know its good before I put it on my 440. My question, If I have it running a little rich on a 383 is it still going to run rich on my 440? Also How rich do I want it to be to keep the motor from overheating during break in and how do I get it there?
 
Are you talking about breaking the cam in? Or are you talking about driving the car? You can break the cam in with stock jets.
 
I have limited knowledge, but heres my 2 cents. If it runs a lil rich on a 383 I would expect it to run rich on a 440.

You could unscrew the idle mixture screws since the idle curcuit is open all the time. Could also increase squirter/shooter size. That would give it more gas without removing jets and can be quickly adjusted back to "baseline".

Engine should not overheat during "break in" as long as the cooling system is properly working. Could also place a house fan or 2 infront of the grill of the car during the initial "break in".

If by "overheat" you are referencing valves being exposed to an extended period of a lean mixture, I would expect that tuning the carb to be rich on the 383 would solve that.

I'm sure everyone you talk to will have a different method to their madness, hopefully some other peeps will chime in.

Bad Shrimp
 
Thanks for the advice. I've ran into a few more problems now. I mounted the new carb on the 383 to try and get it adjusted but I cant get it to idle much below 2000 rpm. It seems to run good above that but below 2000 it dies. I had to set the idle adjusting screw at 2000 so I could adjust the floats. I messed with the mixture but it didnt seem to make a difference. Currently I do not have the gas pedal and trans linkages hooked up. I didnt see a reason to do so. Correct me if I'm wrong. I do have the vacuum line hooked up to the distributor. And I didn't hook up the electric choke because its a manual choke manifold. Also the carb is mounted backwards because I couldnt get it to fit the manifold the correct way. (Some kind of crazy vacuum line that goes from the exhaust on the intake into the car is in the way.) Shouldn't hurt anything should it? What could it be?
 
sounds like giant vacuum leak somewhere, (PVC??) U got to mount carb correctly. Take a pic and post, its got to be fixable...
 
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