Heater hose orientation

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Longgone

Longgone

John/68 Barracuda & Dart
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Does anybody know the proper heater hose orientation for both big block and small block? Right now on my big block I`ve got the right side of the heater core going to the rear most connection on the engine. The small block is plumbed ,right side of heater core to water pump, left to intake. What is correct?
 
If you have a factory service manual, check it out they usually have a diagram of that in there.
Dave C.
 
I did look inside the factory manual and I have found a diagram for /6`s and smallblocks. On the smallblock the hoses should run from the right/passenger side of the heater core to the intake and left to the water pump.The slant runs from the right/passenger side to the rearmost of the two connections. The left runs to the foremost connection. It looks like I need to do the swap on my smallblock, I`ve got them crossed. I still haven`t found a diagram for the big block but based on what I`ve found, the right/passenger side hose should connect to the rearmost connection and the left to the foremost.
 
Small block: Water pump to left (driver)side heater core.
Intake to right(passenger side) heater core.
 
why would it matter? just curious. unless for a correct resto.
 
sweatybetty said:
why would it matter? just curious. unless for a correct resto.
Click to expand...

There`s an inlet and outlet to the heater core as well as a flow direction to the coolant through the system. Naturally to get the most of your heater and cooling system you`ll want everything to flow the correct way.
 
no replies talk about hose diameters. my s/b 340 has 1/2" and 5/8' hoses for
heater core. i would like to know : what dia is feed and what dia is return?
i want to backflush heater core. i can't get heat. have no shutoff valve at
present. this would help all us newer mopar guys. thanks.
 
Off hand I dont know which is which, but keep in mind on non ac cars the coolant flows continuously thru the heater core whether you are asking for heat or not. THe heat is regulated by blending with outside air from the passenger side floor vent box. Not sure about AC cars, they may have a shut off for the coolant flow. If your's has a shut off valve, then the valve is probably shot, or maybe the vacuum selector is not working, etc.
 
jerry's demon said:
no replies talk about hose diameters. my s/b 340 has 1/2" and 5/8' hoses for
heater core. i would like to know : what dia is feed and what dia is return?
i want to backflush heater core. i can't get heat. have no shutoff valve at
present. this would help all us newer mopar guys. thanks.
Click to expand...

The inlet to the heater core should be on the passenger side and be fed by the hot water coming from the intake. This is on a non-AC car.
 
That the first I've ever heard that. I've seen post on Moparts about it and they've all said it doesn't matter. I guess I'll do it like you guys are going to do.

Lee
 
As Jerry said, the heater core as different sized nipples and the engine should also. The smaller of the two is the inlet on the core or outlet on the engine so it would be on the outflow side of the cooling system. The larger of the two is the outlet on the core and goes to the inlet side of the pump. Just like a hydraulic system you want the larger hose to be the suction hose.

Chuck
 
I just picked-up on this thread this morning because I'm in the market for a new heater core for my Dart.

I'll give you a little background on my need and try not to make it too long. Back in the day when I was still using my Dart as my daily driver I was having over heating problems so I took the radiator out and had it boiled and cleaned, what ever they would do at a radiator shop. Some time after that my heater core started to leak. I went back to the shop that had done the work on the radiator and bought a heater core from them. I like to be loyal if I'm treated right and taken care of. Move ahead about 6 months and the heater core starts leaking again, I take it out and bring it back to the same shop and let them know about my problem, they say they will test it and see what is wrong. I get a call from them a couple of hours later and they tell me it is leaking because it is the wrong core, it for a 6 cylinder motor. I tell them that I bought it from them and that is the one they gave me for my 340, then the guy says it is past the 90 day warranty and I would need to buy a new one. Needless to say I was so pissed off that I told them they could keep it and from then on I ran with a heater core and just routed my one hose from pump to block.

I was doing some searching online for one and if you look at the link here you will see at the bottom of the page it has a description and it says 5/8" inlet and 5/8" outlet. What do you guys think about this??? I really would like to get the correct one back in my car as I'm starting to restore it for a fun street car, leaks and problems are not fun.

http://www2.partstrain.com/products...9~DODGE~DART~8~5-dot-2~DART--001.html?index=1

Thanks,

Rich
 
See that's what I was thinking that mine are the same size. On the original one and the aftermarket one.

Lee
 
Which makes me worried that I haven't got what need yet and getting ready buy some hoses to finish this.

Lee
 
The only differences I know in the heater cores are; after around 1970 the tubing connections changed to 1/2" and 5/8" instead of both being 5/8". In addition after 73 the core is a little larger. Other than that, I believe that all non-AC heater cores from 64-69 are the same, regardless of engine size. If somebody knows otherwise please chime in, and Rich, it may be time to change radiator shops.
 
jerry's demon said:
no replies talk about hose diameters. my s/b 340 has 1/2" and 5/8' hoses for
heater core. i would like to know : what dia is feed and what dia is return?
i want to backflush heater core. i can't get heat. have no shutoff valve at
present. this would help all us newer mopar guys. thanks.
Click to expand...

On your car the hoses can only go one way. Which hose goes where on your car?
 
If the nipples are the same size then it would not matter which way the coolant flowed. It will flow the same in either direction.

I have never heard of a heater core being different because of an engine size. That sound like an excuse to me.


Chuck
 
thanks guys, for the info. my car is an orig. air car. i think it still has the orig
htr core, but won't bet on it. anyway, the 1/2" hose connects to the intake
and 5/8" to the water pump.incidentally, the 1/2" core nipple is on the pass. side i will flush core tomorrow from 5/8" hose first.
thanks again.
jerry
 
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