Cooling a 354 Truck Hemi

This is my first rodeo so I thought I would get some feedback before I throw money at this.

I have a 354 hemi with truck heads so water must be plumbed to the intake manifold. I have a Weiand dual 4bbl intake with 4 1/2" NPT ports that I will connect my coolant lines to. I also have a remote thermostat housing that has a GM water neck to go to the radiator. I am running a SBC water pump up front.

First, do I need to connect to all four water ports in the intake? If I only connect to the front two will I differentially cool the engine?

Second, I want to run AN fittings and braided lines. What size line should I use? It seems to me the thermostat is the bottle neck in the cooling system and coolant lines should have a cross sectional area at least equal to the area open when the thermostat is wide open. However, if you have your coolant split between two lines coming off of the remote thermostat then the cross sectional area is additive for both coolant lines. That is to say a 1" sq. hose works the same as two 1/2" sq. hoses. The reason I'm bringing this up is -18 AN fittings aren't cheap. Can I get away with smaller fittings if I am distributing the cooling to 4 ports?

 

I suppose the easy way is to try just the front 2 - emulating the factory set up. You could always add in the rear two later if the flow isn't enough.

BTW two 1/2 sq. hoses equal HALF of one 1" sq. hose.

.5 x .5 x 2 = .5

1 x 1 = 1 (obvious I know)

 

First, check the center water crossover (which is usually an exhaust cross over) against the Weiand intake to make sure the intake will cover and seal the extra tall truck crossover opening. Second, the last two water ports were only used for temperature sending units and sometimes heater hoses so they aren't really needed. Last, the truck, and most other wet type Hemi intakes only used the front intake water ports, along with the 55 to 58 Hemi's that brought water though the front out lets in the heads, so you shouldn't have uneven cooling. As far as AN fitting sizes! On an early Hemi???

 

I think the flow adds. .5+.5=1

Thanks for the insight on the functionality of the back two ports. I'll just run lines to the front. The intake and gaskets accommodate the taller center crossover.

So as not to offend the traditionalists (AN fittings do pre-date this motor) I'll rephrase my question. What size ID hose should I use if I run the two front ports to a remote thermostat?

 

They don't make a -18 hose, well maybe for a tractor or something, -16 is your 1" and that may be a bit small. I use -20 hose and fittings and you can get thermostat housings for that size as they are used in cup cars (peterson; CV products; maybe Bo Laws-i don't think you can get them from earls or aeroquip.
If you do the 2 front ports there are -12 AN fittings machined for this purpose that'll bolt up to either sbc or bbc bolt pattern, the fittings are male flanges so the hose end will screw directly on, those fittings are available from peterson, cv products, and probably a number of the water pump people like CSI and meziere
FYI the engine dosn't predate -AN stuff, it just wasn't common. If you need help with resources, need pics etcetc just pm me, i do this all the time. oj

 

Nope, doesn't work like that. It's about the AREA. You origionally said square lines and technically they're round and so the values are actually a little different but the principle is the same.

A 1/2" square line has an area of .25 sq. inches (.5 * .5 = .25) double that for 2 lines and you get .25 + .25 = .50 square inches.

A 1" square line has an area of 1 sq. inch. (1 * 1 = 1)

So you would need FOUR 1/2" square lines to equal the area of a single 1" square line.

And in this case we are probably really talking about round lines so the area is A=pi (r)(r) aka "a pie r squared"

Which makes the numbers slightly different but the relationships are all the same.

So for 1/2 lines that'd be:
A= 3.14 * (.25 * .25) = .196 sq. inches

& for 1" lines that'd be:
A= 3.14 * (.5 * .5) = .785 sq. inches

YMMV but your numbers ought to be the same.

 

If you have a stock truck intake, flip it over and you will see that the water p***ages from the front head ports to the thermostat housing are less than 3/8" in diameter.
You will be fine using -10 or -12 hose. You will find that using AN fittings takes alot of room.

Here is a truck intake I converted to a 4bbl. I had to reroute the water with hoses.
Another option would be to come off the front of the heads with a water outlet kit like I offer.

 

Thanks for the advice! The water ports coming out of the Weiand intake and going into the remote Offy thermostat are 1/2" NPT so I think I can go as large as 5/8" ID hose (AN -10 I think), which sounds wider than stock.

Your right HemiRambler, I was being lazy and not indicating the .5 was area, not diameter.

 

Idahorocks, I gues we were BOTH right

 

Two things,..

1.) Does T R Waters have site with the 354 truck head outlets available?

2.) On the 2 bbl intake conversion do you have to block off the center water crossover and if so what do you use?

Jeff