Additional cooling lines for the block
Thread Starter
Melting Slicks
Joined: Mar 2002
Posts: 2,164
Likes: 7
From: Beringen
Additional cooling lines for the block
I have a Stewart Stage III waterpump that has provisions to tap it for additional cooling lines for the block. Should I consider doing this ?
Burning Brakes
Joined: Sep 2005
Posts: 993
Likes: 3
From: Iowa
Well that depends on what you are doing with the engine. On sprint cars we will take water out of the head right below the center two exhaust valves in an attempt to save the head from distorting as much. We also pull water from the center of the block (between the center cylinders) and from the top of the heads so it's a little involved. The main idea is to identify an area where you think you want better water flow and plum it there. Is this a street car build?
Burning Brakes
Joined: Sep 2005
Posts: 993
Likes: 3
From: Iowa
For a street engine I would not get too carried away unless you plan to do some road racing in the future. If I was going to do anything I would first, (depending on what type of intake you have) plumb the intake to pull water out of the heads and then plumb the cylinder heads to pull water out from under the center exhaust valves. Anything further would really start to become overkill. What intake are you running, well, could you give me some specs on this engine?
Burning Brakes
Joined: Sep 2005
Posts: 993
Likes: 3
From: Iowa
If it's going to see any extended high RPM usage you have enough cylinder head to warrant some additional plumbing; plus you will help reduce the amount of material removed from the heads when the engine gets freshened up. I'm not familiar with the intake, I know it's similar to the hilborn injection we use on sprint car engines but it seems to be geared towards a street engine. We can do a lot of plumbing with the hilborn stuff so you may have an easy time doing it on that one.
Thread Starter
Melting Slicks
Joined: Mar 2002
Posts: 2,164
Likes: 7
From: Beringen
Some people said that it would disrupt coolant flow..
I was going to tap the rear passages and run them to the thermostat and add an additional water inlet in the block somewhere under the two center valves to aid cooling there.
I was going to tap the rear passages and run them to the thermostat and add an additional water inlet in the block somewhere under the two center valves to aid cooling there.
Burning Brakes
Joined: Sep 2005
Posts: 993
Likes: 3
From: Iowa
Well we have never had any problems with additional plumbing and have seen some great benefits! It sounds like you have the right idea and you will be happy with the results. Let me know if you need anything else.
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Team Owner
Joined: Apr 1999
Posts: 21,953
Likes: 1,444
From: Reno Nevada
2024 C3 of the Year Finalist- Modified
Here are my two rear cooling lines - no more air because of low radiator filling point. The other benefit is the additional flow coming out of the rear of the heads. Most people plumb it all with A/N fittings and steel braided lines
Last edited by gkull; Jun 7, 2008 at 11:12 AM.
Team Owner
Joined: Apr 1999
Posts: 21,953
Likes: 1,444
From: Reno Nevada
2024 C3 of the Year Finalist- Modified
Years ago i had a book called: "How to Hot Rod Small Block Chevys"
It was written around the early 70's. But it had input from all the great engine builders of the time. They do have a section on external cooling lines for the 400 small block.
The cooling pump on our old blocks forces cold water onto the front of each block cylinder water jacket. Flowing to back and then up through the heads and out the front of the top of the intake manifold.
The rear cylinders tend to get hotter. My twin lines allow flow out of the rear most part of the heads and the high filler point ensures that you don't have air pockets.
It was written around the early 70's. But it had input from all the great engine builders of the time. They do have a section on external cooling lines for the 400 small block.
The cooling pump on our old blocks forces cold water onto the front of each block cylinder water jacket. Flowing to back and then up through the heads and out the front of the top of the intake manifold.
The rear cylinders tend to get hotter. My twin lines allow flow out of the rear most part of the heads and the high filler point ensures that you don't have air pockets.
