1965 390 w/AC heater hose connections

[sfalco1957]

Arghh... Just got this 1965, Florida car. I am in New York so heat would be nice, there is none. I started to chase the vacuum network, I found that the vacuum motor for the trap door in the heater box was unhooked, I found the hose and rehooked. No help really. Then things went really off the rails. I was looking at the heater hoses under the hood, and found one connected to nothing. I then looked at the water pump, and there appears to be a plug where I think a hose should connect to, There is also another plug on top of the motor, I guess that is the other heater hose connection. There are hoses connected to both the heater core and the intake manifold at the base of the carb, but basically just for show. Apparently someone has bypassed both the cooling for the carb base and heater core completely. I may as well replace the heater core now, since perhaps it was leaking and that is where this travesty began. I have the lower dash apart, and if I remove the heater box cover I think I can get access to the core and remove if from inside?

Does someone have a diagram of how these heater hoses are supposed to be connected? I assume maybe two loops, one for the carb base plate and the other for the heater core? I also saw references to some kind of heater control valve which appears to go inline with a heater hose and has a vacuum connection. I do not see that. Is that supposed to be in the engine compartment or under the dash? Maybe that cuts off flow to the heater core when using AC?

I will drain down the system, and remove the small tank and check for a Thermostat to exist (who knows), and replace it if there (cheap).
I then need to get fittings to replace the two plugs I see. The one into the water pump seems simple enough (straight connector). But I am not sure about the one on the intake manifold. Is that some kind of T connector? It would seem that that needs to split, one side to the carb base plate and the other to the heater core? I see the Y connector would join the two paths (return?) to go into the water pump, but I would think the 'supply' also has to be split?

Once the heater core is back into play, I can then see about any vacuum network problems. I also found a broken connection on a vacuum canister bolted to the right inner fender, which I think is for the AC. I fixed that with jbweld.

Sorry for so many questions, but I was unable to find a good diagram of all this. Any help would be appreciated!

[jopizz]

Cars with A/C have a water valve. It is between the carburetor base hose and the heater core if I remember correctly and is vacuum operated. Here are two diagrams. The first is the standard non-A/C heater hose configuration. The second is the water valve that is added to the circuit. Hopefully someone with a '65 can post a picture so you can see it in more detail.

John

65 heater hoses.jpg
65 water valve.jpg

[OUR5T8BIRD]

Actually , I found the most help for the A/C heater routing of water and vacuum to be in the " Jim Osborn " 1965 Electrical Assembly manual rather than the '65 shop manual . If you have one of those, think is around the page 50 and on in the manual . If you do not have one, I highly recommend you find one .

[sfalco1957]

Thanks. I see a place that sells a Y-fitting that goes into the intake manifold, I assume that is so one side can go to the carb spacer, and the other to feed the heater core. https://www.wilsontbird.com/parts/19...fold-y-fitting
Would it matter which heater core line this water valve goes into? I see those are available also, hopefully I can find where to hook the vacuum line to it.

Also I just scored a copy of that Jim Osborn manual on ebay, thanks for that tip.

[jopizz]

Here's a picture of the y pipe that comes off of the water pump hose and connects to the rear of the carb spacer. I believe the water valve goes on the water pump hose rather than the intake hose although I don't know if it makes any difference. On Squarebirds the valve is on the hose coming from the intake which makes sense. I would think you want the valve to shut off water before the heater core rather than after.

John

65 heater y pipe.jpg

[sfalco1957]

Thanks so much for the picture. The only piece I don't have is there seems to be a metal U-pipe off the back of the carb spacer that directs it forward to go back to the pump through that Y-connector... It does seem that the water valve would go into the 'supply' side to the heater core. I wonder if anyone makes that U-pipe, if not I guess I could make one with a couple of 90 degree elbows.

[YellowRose]

Steven, I just talked with Clint ~ Clint66 on the phone about that part. You need to get to know Clint as he has a number of '66 Parts Cars he can pull parts off of. He said he will check your post, and later tonight, check and see if he has that part. He said that some of the parts on his '66's also apply to the other Flairbirds. The problem is that parts are known to rust out over the years. He will check your thread and let you know.

[sfalco1957]

Awesome, thanks a lot.

[jopizz]

That part was not used on 1966 Tbirds. 1965 was the last year for the heated carburetor spacer.

John

[jopizz]

I found a better diagram of the system. The water valve does go on the intake hose.

John

64-65 coolant hoses.jpg

[sfalco1957]

Perfect, thanks. I can not find that metal U-pipe anyplace, I guess i can just use two 90 degree elbows worst case. If anyone knows where I can get that pipe let me know.

[jopizz]

Are you going to clamp the hose to the choke? That's why they needed the U pipe because the bend was too sharp. In the 62-63 Tbirds they didn't clamp the hose to the choke. They just connected the heater hose to the carb plate and used a gradual bend.

John

[sfalco1957]

Hmm, do not have any clamp either. I can use 2 elbows and keep the hose close to the carb as the u-pipe would do. Is there a reason it needs to clamp there? I could rig something up if needed. the carb is not original either, choke seems to have 2 wires to it so maybe there is no reason to clamp that hose next to it? The carb is another whole thing, as it seems much different than the stock one I see in pictures. It is marked 'Summit' as in the racing products company I guess, and seems strange as to how it is connected. I will get a couple pics of it. I am not sure the secondaries would even open, there is linkage on the one side that is not even connected to anything. I may end up ditching it and try to get a more stock replacement.

[jopizz]

It sounds like you have an electric choke so you would not need the heater hose to clamp to it. You just need to hook it up to a switched power source. The stock Autolite 4100 carb had a heat activated choke. The hose was clamped to it to help it warm up. I would not recommend going back to the stock carburetor unless originality is important to you. The newer carburetors are designed for today's fuels. The stock carburetor was not and does not play well with Ethanol based fuels. If you are going to replace it I highly recommend an Edelbrock 1406.

John

[simplyconnected]

My understanding is, the exhaust crossover heats the intake which is helpful in Northern Winter months. Once the engine comes up to heat, the heat riser valve opens but some hot exhaust gasses migrate under the carb so the plate is there to COOL the carb.

More recent engines use a phenolic spacer to isolate the carb from heat and they dropped the spacer with coolant. This makes more sense to me. I also like the idea of blocking off the exhaust crossover. Aftermarket intakes, like Edelbrock, have NO exhaust crossover port

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