New carb causes overheating problem?

I recently replaced my worn out edelbrock 600 with a holley 600, now my SBC wants to jump to 210. When I am driving it will drop to around 190 sometimes as low as 170. With the edelbrock she always stayed around 175. So Wth could be the issue?

 

Lean condition. Need to check the jetting, or for a possible vacuum leak, maybe at the carb base or something.


Just remember lean = fast, but hot.

 

Could you have shanged vac hookup to distributor from manifold to ported when you moved hose to new carb??
--------------------------------------------------------------------------------

 

its a lean condition. read your plugs. fatten it up before you hurt the valves.

 

Or the pistons. Sounds like it is running lean to me also, could be a jetting problem or it could be a vacuum leak. You have plugged all the vac holes that you are not using right?

 

I have yet to find a carb that was jetted right for every engine right out of the box. Sounds lean to me also.

 

Good point, I have seen the large port at the baseplate on the back of the carb missed several times. Its easy to miss on a holley as it is tucked under the rear metering block pretty well.

Also blown a cap off of that port a couple times with good backfires

Scot

 

X2 here,,

 

I have all the ports capped, The large back port is going to a PCV valve as well as the large front port. all others are used or blocked. Which port should be used for the distributor. Is 210 too hot? it never really goes over that.

 

Any word on this?

 

Put the Eddy back on!

 

what they all said is pretty much it.vacuum leak because of bad gasket install or missed plugging up, unused ports or distributor hose is on the wrong port.or you way to lean.and im leanin on lean

 

Yes!! I missed a large port on the front of the carb. I plugged that and also adjusted my distributor. she is running very cool now @ around 170-180. The oil pressure drop to 30 now at idle. The motor also (before dist. adjustment) blew out the manifold and header gaskets. I replaced the header gasket and am in the process of replacing the gasket between the header and block. It must be from pre ignition or something, it was popping really bad and i had a 4 layer metal gasket that it blew right threw. Since the adjustments its not popping anywhere near as bad.

 

Good job