Lots of people use them. Whether or not it helps with cooling issues is debatable.

 

I use them, can't see how it would hurt. I think it would/does help with water flow to the back of the head.

 

It's been a debate on a few forums.Im up in the air about plumbing my motor.Its a BBC I keep reading that it helps cool the rear cyls,thus preventing a lean condition.I have all the stuff to do it , #6 line,the fittings and even the tap .I'm just up in the air as to if its worth it.

 

I did the front to back -6 lines on our Filled to the bottom of the water pump holes.
Seemed to help with getting rid of air and seemed to run VERY consistent temperature.

Then again we, for some reason had trouble getting heat INTO the motor.
Race gas.

We are switching to a completely different combination.

We had a completely closed system, radiator, mechanical pump, fan, etc.

I would do it again on just about any engine, just to get rid of the air in the system and temp consistency.
You could put a valve in the middle of each line to bleed the air too.
We did not.

This is on a BRODIX BBC Tall deck manifold.
It came with the 4 holes, to in front and two in back.
Had the -6 hose and the ends, so we did it to try.
Worked well for our setup.

Your Pal, Gary

 

In my opinion, it's ABSOLUTLEY worth it......... you just have to have where they connect in the front right....
typically you run them into the front 2 holes already in the intake, but that tends to not flow well as the water coming out of the heads seems to block the water flow from the back..... better to feed into the t-stat area or housing.......

 

 

If the flow path is, into the block at the front, toward the back, then up into the head and forward to the front of the head for exit.....

If we're taking water away at the back, what are we accomplishing, besides robbing the water needed for the head? I think its ultra important to bleed air back there but with a small line...-3 or -4.

 

If the flow path is, into the block at the front, toward the back, then up into the head and forward to the front of the head for exit.....

If we're taking water away at the back, what are we accomplishing, besides robbing the water needed for the head? I think its ultra important to bleed air back there but with a small line...-3 or -4.

I also like to put water in at the lower center of the block (I use the block drains as an inlet) or if the heads will do it (sbc only here), I like to put water in by the exhaust ports

This photo isn't the best but you can see 2 lines from the pump to the drains, the bypass hose so that a thermostat can be used for faster warm up, and the 2 lines from the rear of the head to the front. There is also a pressure balance line on the front right valve cover and 2 external oil drains on the rear heads that you can't see. Lots of plumbing on this one.

 

So you don't like mine?

 

I've done the same thing many times.... I'm just discussing what I think is probably more correct unless someone can give me an explanation correcting it.

 

I have seen some blueprints that came from GM from back in the 18 degree maybe sb2 days.It show sizes and how to route the plumping.What I took from it with my 23 degree sbc is that all the extra plumbing is not doing anything or hurting it.What i do now is pay careful attention the the alginment of the block, head gasket and head of the water port below the center exhaust ports.I havn't used lines from the back of the intake but as Chris says a -3 or -4 might be a good ideal.

 

I plumbed mine with a -6 from the pump to the middle of the head at the exhaust ports. Then -6 from the back of the intake to the front.

 

That's exactly what I am running on my SBC & temps are perfect

 

After Pulling the intake on one car I found bone dry pockets 3-4" into the heads. That car the temp gauge would stick/fluctuate kinda on start up some and it stopped with the bypass lines. I've also read large lines can take longer to warm up if the lines are plumed as a bypass. Recently even read that too large lines at the rear can cause hot spots in the center of the head because it evens out the flow to much, but idk about that. The basic area of two 4an lines and small hole in the t-stat is about the same area as the bypass in the block that normally gets plugged. C4 corvettes came with a 3/8 line out of of the rear crossover coolant passage of the tpi intake, so did some older gen but I can't rem if it was c1 or c2.

 

I had a overheating issue with my circle track car and doing this mod helped.

 

What about tapping into the water pump outlets, and then plumbing that to the back of the intake/heads? That should route some of the cooler water from the radiator directly to the heads.

 

I've seen people run the line from the rear of the intake into the suction side of the pump using the heater core port and that's what I did on my c4 when I deleted all the other coolant lines since the t-stat housing is such a tight fit already.

 

We use the port between the center cylinders, plumed to the Ther/stat.

Just going from the rear to the front of the intake water bosses may only connect the two and add some volume.

 

seems like a reverse flow set up would be better...remote water pump, up from bottom of radiator to a distribution manifold,from there to thermostat housing,small lines from distribution manifold to back of heads and between exhaust ports then, lines from where water pump would have bolted up to a Y then one line back to top of radiator

 

So weather or not doesn,t really effect anything?Maybe just #6 line will forsyth.

 

http://imageshack.us/a/img341/282/intake2h.jpg

 

What is this CHRIS,pro stock technology?FordSux:

 

someone explain?

 

That helps to keep the hose cool.

 

I route mine like in post 12. I use braided line but there's nothing wrong with hard line. I have also run a line from the water pump to the center of the head between the exhaust ports but didn't see any noticeable difference.

 

On lines from the rear of the intake to the water neck, several of my dirt track customers say it's lowered the engine temp considerably.

 

Where does everyone feel is the appropriate spot to measure temp? Some measure in the intake by the water neck, some measure in the head below the headers.

 

When nascar ran the sb2 was it common to run a line from the high pressure side of the water pump to the side of the block between cylinders 3&5,4&6?

 

When nascar ran the sb2 was it common to run a line from the high pressure side of the water pump to the side of the block between cylinders 3&5,4&6?

No, they let the water out and returned it to the low pressure side of the radiator......

 

JEEEEEEEZZZZ.....:SHTF

 

Oops gotta correct myself think it was a 5/16 line on the vette I rem it being a weird size now.

 

I always plumb ffrom exit of water pump to center exhaust cylinders. Center intake return to thermostat spacer plate under housing. I was always taught to give it plenty of flow and let the radiator do what it's designed to do. I haven't seen any line hurt temperatures other than one that leaks or sucks shut.