Cylinder head mods for cooling

[Stevie G]

Anyone have any info on tapping the heads on a SBC for improved cooling?
Someone borrowed my Performance book that had the info in it.
Looking at the mod that taps the head between the middle cylinders.

TIA,
Stevie G

[unklian]

I think that had something to do with venting steam pockets,but only works on Aluminum race heads.
Street heads have the exhaust crossover passage there.
Newer Vortec heads might be different.

How about running reverse cooling instead?

[Stevie G]

I think that had something to do with venting steam pockets,but only works on Aluminum race heads.
Street heads have the exhaust crossover passage there.
Newer Vortec heads might be different.

How about running reverse cooling instead?

I have Performer RPM heads going on a 400 small block.
The steam pockets are exactly what I'm concerned about.
Tell me more about reverse cooling.

[unklian]

That what all the new smallblocks run.I've got it on my '95.NOt sure when they started.
The old style took the cooled water from the rad into the block,then into the heads,and back to the radiator.So the water was heated by the time it got to the heads.
With reverse cooling,water goes to the heads first,then to the block.

Sorry,no idea if the new style pumps can be retrofit to an older block.

[Bib_Overalls]

Reverse cooling will not substitute for steam holes.  You need the steam holes and you will be sorry if you don't run them.  Stock 400 heads came with steam holes.  They run from the face of the head to the water jacket.  400 blocks have siamesed cylinders and they tend to run hot.  If the coolant turns to steam it forms a pocket next to the cylinder that does not cool.  You dont want that.  The holes alow the steam to vent into the cooler heads where it condenses.  This link
http://www.trickflow.com/product/chevycylinderheads/23degree/pr_23degree_installation.htm

explains how to drill the holes.  Any automotive machine shop can do the job for you.

[Stevie G]

Reverse cooling will not substitute for steam holes.  You need the steam holes and you will be sorry if you don't run them.  Stock 400 heads came with steam holes.  They run from the face of the head to the water jacket.  400 blocks have siamesed cylinders and they tend to run hot.  If the coolant turns to steam it forms a pocket next to the cylinder that does not cool.  You dont want that.  The holes alow the steam to vent into the cooler heads where it condenses.  This link
http://www.trickflow.com/product/chevycylinderheads/23degree/pr_23degree_installation.htm

explains how to drill the holes.  Any automotive machine shop can do the job for you.

That's already done.
I'm looking for info on rerouting coolant from the middle of the heads back to the T-stat housing.  the other method involves a sleeve that makes an internal bypass.  I've seen it in the Chevy performance book but like I said, someone borrowed my book.  The book refered to it as a Hendrick motorsport modification.

[Bib_Overalls]

You can tap your intake manifold in the back to open passages into the heads' water jackets and run hoses to a thermostat adaptor.  This is a common racing modification but it is not something you see on street motors.  What are you going to run this motor in?

[Stevie G]

You can tap your intake manifold in the back to open passages into the heads' water jackets and run hoses to a thermostat adaptor.  This is a common racing modification but it is not something you see on street motors.  What are you going to run this motor in?

I have an S-10 that is set up for the Silver State Classic.