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The O.P. issue is an easy fix. He doesn't want to leave coolant in the core. He wants it drained and dry. You don't need valves, pipe plugs, etc.
Put the car up on ramps.
Drain off some coolant.
Remove both heater hoses off the core.
Install Dorman adaptor, part # 47080
Refill Rad, done.
I have a shut off from the water pump in line now to the heater, however if I don't put another one in the return line and disconnect the lines from the heater core, will not antifreeze come back from the radiator?Probably a DUMB question but I don't know the answer sorry.
I found a fitting to go between the two hose sizes at advanced auto. That said, on the 80 the problem I had with making the loop from the water pump up to the manifold was that it was just too tight a bend to go direction and took too much hose to make a gentle loop that I felt wouldn't collapse. So I just plumbed some copper fittings to make a 180 bend so the hoses could be kept short.
I did just cap the ports initially, but seems the caps I got were crap. Even Napa (still chinese). After under an hour of engine running they were starting to develop cracks. Plus I read there is some thought that before the thermostat opens having the pump circulate coolant through the block and heater core helps to keep the cylinders closer to the same temperature. Without this circulation the inner cylinders, #4, 6, 3, and 5, will run hotter and thus expand that area of the block more. In theory the temperature differential in the block and resulting different expansion can cause additional stress in the block. True? Well, I would say yes but whether it's severe enough to create failure I don't know. That said, it was easy enough to just build a loop vs. capping the ports, which as mentioned had it's own issues. For what it's worth.
I picked up a replacement nipple at one of the auto box stores so I could do the loop bypass with the same size hose. I'd have to swap back to get heat in the car, but that's fine for me.
I don't know how long it had been in the car, but one if those adaptor plastic pieces broke apart when I inspected it. There is nothing but metal fittings and rubber hose in the cooling system now.
I have added ball valves to my lines and have a question that I don't believe has been answered.
Should I open them to allow coolant into the heater core and then shut them off again? Or is it okay (or preferable) to leave the heater core dry if I don't think I'll use it?
I have added ball valves to my lines and have a question that I don't believe has been answered.
Should I open them to allow coolant into the heater core and then shut them off again? Or is it okay (or preferable) to leave the heater core dry if I don't think I'll use it?
it doesn't matter....unless you make a way to blow air into the heater core to push the fluid out (and I don't recommend this) there will always be coolant in them....the ball valves only restrict the flow of the coolant it doesn't do any thing to assit in draining unless you disconnect the ends from both sides of the heater core and blow air into it...(I don't recommend doing this its too easy to over pressurize it and create aleak)
I have a shut off from the water pump in line now to the heater, however if I don't put another one in the return line and disconnect the lines from the heater core, will not antifreeze come back from the radiator?Probably a DUMB question but I don't know the answer sorry.
Thank You
there is minimal flow more like hot water rising and cold water falling so you get some heat....in Michigan I doubt it matters
Here is what I did... I connected the two heater hoses that go in and out of the core with a brass Fitting that has the correct Diameter for each heater hose and covered the in/out brass tubes of the heater core with rubber caps. I did the Bypass right at the heater core to Keep the original look in the engine bay and it is easy to convert back to stock... There is no Need for a heater for me since I only drive my car in summer weather... It also prevents that the core goes out eventually making a huge mess! The cab is also not that hot anymore, since even with the heater dials in "off" Position the heat from the core is never shut of completely... I like it the way it is for me now... Of course only for Summer driving!
Here is what I did... I connected the two heater hoses that go in and out of the core with a brass Fitting that has the correct Diameter for each heater hose and covered the in/out brass tubes of the heater core with rubber caps. I did the Bypass right at the heater core to Keep the original look in the engine bay and it is easy to convert back to stock... There is no Need for a heater for me since I only drive my car in summer weather... It also prevents that the core goes out eventually making a huge mess! The cab is also not that hot anymore, since even with the heater dials in "off" Position the heat from the core is never shut of completely... I like it the way it is for me now... Of course only for Summer driving!
It's time to change my heater core hoses in my '70 SBC and I also thought of bypassing the core to reduce heat in the passenger compartment and avoid a leaky mess in the future.
Where did you get the brass fitting for the two different size hoses? Can I access the core area hoses by removing the side egg crate?
I've also thought of just plugging the water pump and intake, but some guys say you need the water flow? [doubting this]
It's time to change my heater core hoses in my '70 SBC and I also thought of bypassing the core to reduce heat in the passenger compartment and avoid a leaky mess in the future.
Where did you get the brass fitting for the two different size hoses? Can I access the core area hoses by removing the side egg crate?
I've also thought of just plugging the water pump and intake, but some guys say you need the water flow? [doubting this]
A lot of good info in this thread. Thanks
I found an adapter with the two different hose size ends at Advanced Auto. In the end though I found that bending the hoses took too much distance to do without kinking. So I just soldered a couple of 1/2" copper elbows together in a "U" shape. Both hose sizes were flexible enough to squeeze down on the same size fittings with hose clamps. My understanding is that the theory on looping the hoses even if the core is missing is that it allows water to circulate in the block before the thermostat opens. This can then keep the block temperature more uniform. At some level it makes sense since the middle cylinders (3, 4, 5, and 6) don't have as much outside surface area to dump heat as the corner cylinders. So stresses build up as those areas of the block heat up and expand more than corner areas. The question then is whether it is enough stress to cause damage after many heat cycles. I never bothered to try to find out. I figured I'd spend less time making the loop than I would getting a factual answer.
Last edited by vince vette 2; 12-17-2018 at 10:57 PM.
The reason for two shut-off valves is it is a fifty-year-old heater core. cuz if the heater core springs a leak either hose will give you coolant flow into the heater on to the rug.
1/2” pipe plugs. 1 for intake, 1 for waterpump. There is no requirement for flow. Put some rubber caps on the heater core tubes if you are concerned with debris, it’s easily reached from under the car.
If you wish to keep the heater core in the loop then I would have to agree with derekderek on using two valves.
Eddy
Last edited by 74_stingray; 12-18-2018 at 06:40 AM.
05-20-2018, 09:52 AM
There are these engines in stationary applications with plugs in the heater circuit that work just fine.
