Does anybody know...

[Rktpwrd]

Hey everyone
I just finished a complete drivetrain swap in Project Olds Cool, which included retiring the worn out old 305, and replacing it with a built 350 Chevy.
The car was originally an AC car, but it never worked since I got it. Because we really only have maybe a dozen times a year where we really need AC, the pump, lines, evaporator, condenser etc was removed to tidy things up.
I replaced the heater core along with all the fittings and hoses but kept the original AC HVAC box. The heater hoses are routed the old school way directly to the heater core and back with nothing inbetween.
The HVAC fan is only blowing regular air, no heat when it's on the heat setting. I'm about 80% sure the blend doors are working and in the correct positions as I didn't change any of that during the swap. Which brings me to my question:

Does anybody know if there needs to be some sort of flow restrictor inline in one of the heater hoses or heater hose fittings in non-AC 305 or 350 applications?

I know some engines like my 455 had them built in to the heater hose fittings to restrict and slow coolant flow through the heater core.
The fitting in the top of the water pump is the only stock fitting I was able to use. I've done a Vortec head swap and the Vortec intake manifold only has provisions for 3/8" thread fittings, so reusing the stockers was out.
The water pump is new, and both heater hoses get hot, so there's obviously flow through the heater core.
If the answer is no, there's no flow restriction needed, the next question obviously becomes "why then, is it not blowing warm air"?

Here's a couple of photos for reference if needed.

Any insight or information provided would be greatly appreciated.
Thanks in advance.
Donovan

 

[drogg1]

Well if the core is new and the hoses are getting warm/hot meaning there is flow, I would guess you have an air delivery problem. I can't imagine a decrease in flow would mean the difference between cool and hot air.

I would make sure all electrical is performing correctly and you have all fan speeds.

Then I would make sure all the vacuum lines and etcetera associated with the system are working even though you said these have not been modified.

It is fairly common to blow the fan speed resistors as well have some vacuum problem.

 

[soma]

just posted a reply but noticed you said yours used to have a/c for some reason i thought you said it was a non a/c car.anyway i think your misisng the head units vacuum source.on mine there is a vacuum line that is routed from the dash through the fire wall that atleast on mine is routed around the a/c box in the engine bay to a vacuum canister that gets its vacuum from a manifold source tied in to a check valve.i think without this vacuum the diaphragms controlling the blend doors in the plenum wont work.may be wrong but worth a look

 

[Rktpwrd]

just posted a reply but noticed you said yours used to have a/c for some reason i thought you said it was a non a/c car.anyway i think your misisng the head units vacuum source.on mine there is a vacuum line that is routed from the dash through the fire wall that atleast on mine is routed around the a/c box in the engine bay to a vacuum canister that gets its vacuum from a manifold source tied in to a check valve.i think without this vacuum the diaphragms controlling the blend doors in the plenum wont work.may be wrong but worth a look

Thanks for your response, I think you may be onto something there.
I was under the understanding for some reason that the vacuum ball and the vacuum lines that went into the cabin only controlled the AC side of things at the heater control unit. That's why I said I was 80% sure the blend doors where in the correct positions.
When I removed the AC and related components, I traced the vacuum lines inside the cabin to a junction behind the glove box. I cut the lines at the junction and sealed off the ends to prevent any possible vacuum leaks, but now it sounds like I may have to run a manifold ported hose back to that junction.
I wonder how important having a check valve inline there is...?
Anyone do anything similar or have an issue similar to this?

 

[pontiacgp]

You need the heater valve or you will have high heat all the time. Maybe a dumb question but when you bled the system did you have the the heat on full?. Are both heater hoses hot and about the same temperature? Check to make sure you have flow in the rad, I have got a water pump once from Napa that had the wrong impeller on it.