[78w72]

hi. strange question about replacement heater cores. on factory brass/copper heater cores there is a crimp on the bottom hose to about 3/8. from what i have read that was to reduce or limit flow to the core to avoid high pressure & possibly bursting. thats what i read anyways....

my question is, the new aluminum core i bought does not have the crimp, is that because aluminum is stronger & doesnt need it or because the reman'd cores are cheap & they dont want to spend extra money to duplicate the crimp? i have also read that the outlet in the head is reduced in size to also help reduce flow to the heater core.

i have aluminum e-heads & want to do the dual outlets from the rear of the heads but need to know if i have to reduce the outlet size there too. hopefully the aluminum core is stronger than teh originals & dont need the crimp or reduction fitting in the head.

any ideas?

[RR67GTO]

If you search the threads on here you'll find a lot of information on this. Some people install a plug in the heater hose with a smaller hole. It's worked for me on my two cars. Good luck.

[78w72]

i did a search here & thats where i read most the info, just curious if the reduction is not required on the repro alum heater cores. there has got to be a reason the alum cores dont have the crimped tube....

[Ollie]

Take a pair of needle nose pliers and slightly crimp the edges together in two places 90" apart.

[Formulas]

Your fitting outlet on the head may have a restriction.. if it isnt gone with age or replaced with a inferior part.

[78w72]

i have aluminum heads & the factory pressed in fitting wont work.

actually the factory used both from what i have seen. a reduced fitting in the head & the crimped heater core.

[Formulas]

You could still fashion a restriction at the head. and not worry about the core

[78w72]

true but im trying to keep it as simple & clean as possible. i'm thinking about doint a dual outlet from the back of the heads into a t fitting then into the heater core. i think i may just use a brass plug in the hose right before the core & drill a 3/8 hole.

any ideas on why the aluminum heater core isnt crimped like the factory brass ones?

[BVR421]

because its cheaper not to crimp them

[78w72]

Originally Posted by BVR421

because its cheaper not to crimp them

that was the 1st thing i though of, but then wouldnt there be failing aluminum heater cores all over the place???

any thoughts on maybe aluminum is stronger & doesnt need the crimping?

[78w72]

pic of factory crimp on the heater core & a heater hose fitting with the reduction.

any ideas on doing a dual outlet on the rear of the e-heads??

[My442]

My buddies thought I was nuts to have an original Harrison heater core rebuilt.

A couple of observations: The smaller tube on original heater cores has the crimp. This allows the core to restrict the flow to maximize heat.

If you weigh an original, it is about 33% heavier than a replacement.

It is a major job to replace a heater core in a A/C car.

I feel better using a quality rebuilt original versus a cheap chineseum knock off.