Engine Heater hose restrictor purpose

Mcmahst · May 5, 2025

I’m trying to tie an 87 TBird 5.0 manifold heater flow lines with my 73 heater core. I understand there is a restrictor used in one of the heater hoses. My questions are, 1. Which of the hoses have the restrictor, and 2. Why did Ford use a hose with a restrictor? Here is my setup so far:

I’m still trying to source two molded heater hoses that I can modify to replace that 180 degree hose, so I’ll have a working heater. Thanks.

Noobz347 · May 5, 2025

The "pressure" side, going [into] the heater core, is the one with the restrictor.

The purpose is to reduce shock from pressure changes (extends life of core) in the cooling system and give the water in the block, "heating priority" before the t-stat opens.

Mcmahst · May 6, 2025

So, looking at the two metal pipe off the intake, I’m assuming the pressure side is the pipe attached to the fitting on the intake? And if I omitted the restrictor, I’m back to a stock 73 setup, I guess. How would I modify a custom hose to facilitate the restrictor? BTW, here are the dimensions of the hoses I’m looking for:

I know it’s hard to read. I just need two 5/8” ID hoses with that approximate distance between the two 90 degree and offset by 90 degree of rotation between the bends. And have enough hose to cut to fit. I wish I had one of the older paper catalogs on hoses. As I remember, the dimensional data was available on the present hoses. I’ve tried doing that in the on-line catalogs, but they are not searchable enough to make it work. Thanks for the help.

Noobz347 · May 6, 2025

Mcmahst said:
How would I modify a custom hose to facilitate the restrictor?

it get pushed into the hose:

https://www.cjponyparts.com/heater-core-supply-hose-flow-restrictor-mustang-1979-2004/p/HW3134/

LILCBRA · May 6, 2025

Mcmahst said:
So, looking at the two metal pipe off the intake, I’m assuming the pressure side is the pipe attached to the fitting on the intake? And if I omitted the restrictor, I’m back to a stock 73 setup, I guess. How would I modify a custom hose to facilitate the restrictor? BTW, here are the dimensions of the hoses I’m looking for:

I know it’s hard to read. I just need two 5/8” ID hoses with that approximate distance between the two 90 degree and offset by 90 degree of rotation between the bends. And have enough hose to cut to fit. I wish I had one of the older paper catalogs on hoses. As I remember, the dimensional data was available on the present hoses. I’ve tried doing that in the on-line catalogs, but they are not searchable enough to make it work. Thanks for the help.

Could you use something like this in conjunction with straight hose? I had to do something similar with the upper radiator hose in my II.

Amazon.com

LILCBRA said:
Got a jump on the upper hose replacement. Still waiting for the aluminum tube, it's supposed to arrive later today sometime. But this should show how much the alternator's new position interfered with the hose and how it's going to be routed now. I think it'll work just fine....

LILCBRA said:
Finished the hose replacement today, then moved it into my carport alongside the vert.

There appeared to be a small leak coming from the mounting bolt on the right side of the engine, but there was no trail when I moved the car. I guess I'll have to keep an eye on that location to see if it's sealed itself up or if I'll have to tear back into it again.

Mcmahst · May 6, 2025

Thanks Noobz347 for the source. You’re a gentleman and a scholar.

I’m trying not to use metal 90’s if I can get away with it. But if I strike out on the hose, I will. Thanks for the help Lilcbra.

Mcmahst · May 6, 2025

I’m Trying to get the local Napa guy to let me go in the back and go through all the molded heater hoses to see if I can find something close. He’s gotta get the owners permission lol.

Noobz347 · May 6, 2025

LILCBRA said:
Could you use something like this in conjunction with straight hose? I had to do something similar with the upper radiator hose in my II.

Amazon.com

I clicked on this link earlier today and now Amazon is trying to desperately sell me stainless steel tubing. LoL

Mcmahst · May 6, 2025

I hate when that happens

Rcdgl · May 10, 2025

I just put one in my 82 for the first time ever. It even seems to help cooling!

limp · May 11, 2025

Noobz347 said:
I clicked on this link earlier today and now Amazon is trying to desperately sell me stainless steel tubing. LoL

I heard that Bezo's " wife " had a " blowout' when she became an " astronaut" and he needs money for repairs...

Engine Heater hose restrictor purpose

Mcmahst

Noobz347

Stangnet Facilities Maint Tech... Er... Janitor

Mcmahst

Noobz347

Stangnet Facilities Maint Tech... Er... Janitor

LILCBRA

I wish I didn't have all of these balls in the air

Mcmahst

Mcmahst

Noobz347

Stangnet Facilities Maint Tech... Er... Janitor

Mcmahst

Rcdgl

limp

wrap a little cheese around it and its a done

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Engine Heater hose restrictor purpose

Stangnet Facilities Maint Tech... Er... Janitor

Stangnet Facilities Maint Tech... Er... Janitor

I wish I didn't have all of these balls in the air

Stangnet Facilities Maint Tech... Er... Janitor

wrap a little cheese around it and its a done

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