I got a 406 and want to add additional cooling to the simesed cylinders.
I have a pipe plug inbetween the cylinders on the head .
now where do i tap coolant off the pump?
Ive seen cars in the past with a 406 that had the extra coolant lines plumbed to the heads in that location but cant recall where they got the source from.

http://home.comcast.net/~onovakind67/coolanthole.jpg

Make sure your block has this hole.

http://www.stewartcomponents.com/tech_tips/images/_tec_strategic_flow.gif

Tap the output of the pump.

I got some holes but not for the middle cylinders
http://webpages.charter.net/harrycoon/brodix%201.JPG

The place you want to put the water is right between the siamesed exhaust valves.

I have heard that you can drill between the cylinders through a freeze plug hole. Better be a small hole and get right in the center. Anyone heard of doing this?

yes I heard that aswell
As you can see I dont have a middle freeze plug becaise it wasnt bored out so itll be easy to add a pipe fitting there.

What seems to be the problem ?
21" 3 core stock style (replacement) radiator here and only issue it 100*+ out and running her hard then getting caught in traffic :confused:

406 cu inch (actually 400 smallblock)
are notorious for overheating in the middle cylinders.
also due to that heat the rings usually go first in that area.
since i have the motor out Im thinking of providing additional cooling to that area of the block.

That is true Harry, but the reality of it is unless you are running in endurance type races, you probably will never see a difference. Siamesed cylinders are not the best for perfect cylinder wear, but they are not that bad either. Torque plate hone them and use a good radiator (nothing special, just decent) and you will never see a problem.
As for overheating with the 400, I file that along with information on the 3/4 race camshaft....;)
What kind of performance goals do you have in mind?

just covering all bases.
hate to have an issue after i drop the block inplace.
Im pretty anal about making sure things are right the first time.

Fair enough, it can't hurt. Thats kind of how I feel about steam holes in the heads on 400's too, if it gives you piece of mind by all means do it, but it's not necessary. Good luck with it :thumbsup:

my club is planning a trip up MT.washington next summer and 1/2 way up Id hate to be overheating.
we are going to have a show up there aswell.
touted as the highest carshow in new england

I've been thinking about going with a 406 in my car and was talking to a friend of mine who has one in his Nova. He said he doesn't have any overheating problems with it, he runs a BeCool radiator and twin electric fans.

406's don't overheat any more than any other engine. I've towed trailers 1100 miles with my 406 with a stock small early V-8 Nova radiator, clutch fan and shroud.

I have a 406 in my '68 and although I've never had it blow a hose it gets hot at an idle. Much hotter than any other small block I've had. I still wouldn't trade it for a smaller one though.

I've been thinking about going with a 406 in my car and was talking to a friend of mine who has one in his Nova. He said he doesn't have any overheating problems with it, he runs a BeCool radiator and twin electric fans.


I have the BeCool 24" BB dual electric fan radiator, rated to 700 hp. My motor (408") pulls 500hp/510 tq. I have not ran it in weather above 80* yet, but my fans only come on intermittently even at long stop lights. It normally stays right at 180*, the thermostat rating.

I sure hope I have no issues this summer. I really don't think I will. I guess better safe than sorry though.

My 402 has yet to have any over heating problems either. Oh wait thats because it doesn't have pistons or a crank yet...

always a wise azz lurking somewhere.