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Re: 1961 cadillac conversion

Posted: Sat Aug 08, 2020 7:56 am
by Al9
Malfunctioning cycling switch?

Re: 1961 cadillac conversion

Posted: Sat Aug 08, 2020 11:03 am
by cadillac matt
the condensor is cold and all the air is going through it. i sprayfoamed the core to the case so it's completely airtight. the way the system is, is 2 separate air ducts and vents and 1 fan. it even has 2 separate control heads for heat and a/c. i think it may need more airflow, but i'm not sure how. if it was lack of airflow, it would seem like the air would be really cold, just not enough volume to cool the car. the cycling switch seems to work. it cycles on and off at about 15 psi. is that too low?

Re: 1961 cadillac conversion

Posted: Sat Aug 08, 2020 1:20 pm
by tbirdtbird
Long thread. Has re-heating such as faulty blend doors etc been discussed. Sorry if it has been addressed

Re: 1961 cadillac conversion

Posted: Sat Aug 08, 2020 2:46 pm
by bohica2xo
15 psi 134a is around 15f.

If your lines in & out of the evaporator are cold enough to freeze atmospheric moisture, then the core is that cold as well.

If you are blowing air over an evaporator that is that cold it will be very cold on the discharge side. Well, at least until the core freezes solid from collection of atmospheric moisture.

But since you insist that all of the system air is passing through the evaporator core, wait a few minutes. When the core ices over you should see a big reduction in airflow from the vents. Shut the system down, and watch the condensate drain.

If your problem is ice formation, re-adjust the cycling switch to close around 34 psi.

Re: 1961 cadillac conversion

Posted: Sun Aug 09, 2020 8:40 am
by ice-n-tropics
in humid weather with humid air bypassing evap, and fresh air entering fan (Window partially down on recir.), frost will blow out of louvers.
hotrodac

Re: 1961 cadillac conversion

Posted: Sun Aug 09, 2020 8:43 am
by Tim
ice-n-tropics wrote:in humid weather with humid air bypassing evap, and fresh air entering fan (Window partially down on recir.), frost will blow out of louvers.
hotrodac
Hey Ice. Hope all is well and fishing is good.

Re: 1961 cadillac conversion

Posted: Sun Aug 09, 2020 12:35 pm
by cadillac matt
the way the system is designed is that 1 fan blows through 2 separate sets of ductwork. a flapper door switches between them with no blending. so on hot all the air comes out the floor or defrost, and on a/c all the air comes out the dash vents. all that seems to work. i had considered the core freezing up, but it doesn't seem like the airflow ever changes. could the core freeze internally? would a partially blocked core cause this? the core was modified to fit by old air products to accept the ot and the accumulator. do i need more air flow? should i push this thing out side and light a match to it?
thanks guys for all your help.

Re: 1961 cadillac conversion

Posted: Sun Aug 09, 2020 12:53 pm
by bohica2xo
I have no idea what sort of core they provided. A large, folded fin plate style evaporator like this was common for cars that size:


https://www.rockauto.com/en/moreinfo.ph ... 60&jsn=917

Re: 1961 cadillac conversion

Posted: Mon Aug 10, 2020 8:22 am
by cadillac matt
it looks like a original type core with the inlet and outlet changed. i don't believe it's a parallel flow type. it's big.

Re: 1961 cadillac conversion

Posted: Thu Sep 17, 2020 4:57 pm
by cadillac matt
final update.
after all the f-ing around, i figured it out.
i bought a brand new custom evap core for this project. the core was partially obstructed. when the system was working, only the 1st inch or so of the core would get cold. the rest would be room temp. sent it back and they made me a new 1.
success!! a chilly 32* at the vents today. woo hooo!!!