Technical temperature

How much of a temperature drop can I expect by advancing the timing on a new chevy crate engine. It's currently running 220 and rises as I get into traffic.

 

hard to say....without knowing how retarded it is now

 

you have to experiment as its different for the variables involved , on my truck ( 454) if I retard the ignition to 0 from +24 it runs 12 degrees hotter , on my pontiac if I did that it will run 235* instead of 180* you should be in the 33-36* total ( vac + mech) timing advance range , you can try the old power tune method to see what might work best as your loading the motor till it detonates or pings then backing off ..

 

I would go for around 33-36 degrees total initial + mechanical advance, then whatever the vacuum advance adds above that.

just don't let it ping too much.

 

How much should this drop the temperature, or about how much?

 

None if that's where it is now.

 

post some pics of crate in your ride - new build, or just motor transplant? what type of belt system are you running?

 

It sounds like you're fixing the wrong problem. Tune the engine for max efficiency then build a cooling system to work with the engine.

 

I agree, and I'll add that overheating at idle can often be reduced by using full manifold vacuum rather than ported vacuum.

 

Asking this question in this way tells me you are not very familiar with SBC timing. This is not the way to approach this problem. Timing can be set up in the shop to very close to optimum and the car should not overheat. If it does there is another problem, not with the timing. Get your timing ironed out before even driving it. Then see how it goes.
Timing specs depend entirely on what crate motor we are talking about. But a good general timing setup for an SBC is 16 degrees initial advance + 18 centrifugal advance = 34 degrees total, all in by 2800. Not ideal for all, but will work with most SBC's. More advance via vacuum advance may help overheating at idle, but won't help at speed. Keep vacuum advance plugged until you have the basic timing and the motor running good before even thinking about vacuum advance. It's not a crutch for a hot motor. However, timing is probably not your problem. If your engine and cooling system are healthy and timing is within spec's, the problem is very likely airflow through the radiator. Do you have a good efficient fan shroud? Will the fan hold a rag to the front of the radiator? Is the belt tight? Is the radiator clear of debris? Is the radiator big enough? Are you sure of the gauge and sender? A lot of other things can cause a motor to run hot.