Looking to cool the heads down faster and more efficiently. I have heard mention of modifying the ducting or ports to allow more coolant to move faster through the heads. Any insight into this would be greatly appreciated thanks.

 

I don't think they flow that much to need to be opened. I'd think the passages in the block would benefit more from being opened.

 

have you ever seen SBCs that have coolant lines routed to the outside of the head plumbed right above the center exhaust valves?

 

Why not consider Evans Coolant/System? Cooling the heads down does not necessarily make more power.

http://www.evanscooling.com/main25.htm

 

not trying to make more power per se. Trying to prevent detonation on my setup which is going to have high dcr of around 9.17

I think it is very doable with enlarging the coolant ports and running a 160* tstat and purple ice. might even run a bigger radiator.

 

Do yourself a favor and take the time to read the Evans info. Lowering your coolant temp reduces the thermal efficiency of the engine, possible offsetting the gains of the timing advance. The NPG coolant allows you to retain the higher coolant temp (higher thermal efficiency) while eliminating hot spots that cause detonation. But that's the Reader's Digest version. The detailed explanation on the Evans site has a lot of information in it.

 

From what I have heard there are several folks who say that evans works no better than purple ice or water wetter... although I have strongly considered giving it a try.

I still don't see why enlarging the coolant ducts wouldn't be a benefit in combination with evans. Am I the only one who has considered doing this .. I would figure somebody would have beat me to it I really want to speed up the cooling of the heads no matter what cooling additive I use to limit detonation. The faster the coolant moves through the heads the more heat it takes with it. What about opening up the coolant holes on the head to match the gaskets?

 

How about trying the Evans first, before going through all that trouble? Or is the motor apart right now?

 

I'm on the same mode of thinking as you 1LE. I wanted to enlarge the holes in my V6 when I rebuilt it. How are the holes in the head gasket? That seemed to have the largest room for improvement everytime I look at one.

Another thing to keep in mind IMO, look at where the water comes in at, and where it flows to. The water comes in from the front and the rear of the heads. If what you're trying to do is cool the middle siamesed exhaust ports, then maybe try to enlarge the head/block coolant ports only there. All of the coolant ports are in parallel (electrical schematic speaking) so enlarging all of them will increase overall flow, but not specifically to the middle of the head. If you enlarge the middle ports, then the side ports should flow the same but the middle will outflow them which will cool the middle better.

I think the GM Power book shows you how to drill the head to allow coolant or oil (don't recall) through the middle of the siamesed ports.

 

Motor will be apart to have the heads ported so I figured this would be a good time to do it as I don't want to take them off again. DCR will be more like 9:1 or lower depending on what the combustion chambers cc at and what exactly the stock piston reliefs are as nobody seems to know I just used
6cc as most stock replacement pistons are 6cc.

 

Thanks! I will have to look for a copy of that book.

 

well, couldn't find a copy of that book so any links or info on the subject would be most appreciated! Was also thinking of running a bigger fan on the radiator to help cool as well... any other thoughts?

 

Another angle you may want to consider is this, if you speed up the water it has less time to absorb heat. GM may have those orifices the right size to slow water/coolant down to absorb heat.

Think of it like this...when your A/C is on max and the fan is on it's lowest speed the air is much colder than if you had the blower on high, why? The air spends more time over the evaportator getting cooled.


But the thermostat has ultimate control over water flow.

David

 

Part #
24502488

Chevrolet Power book.