Need of the Heater Control Valve

[Killer Frogs]

EFI swap with a 5.0 from a '00 Explorer. Routing the hoses to the heater core. Is there really a need for the heater control valve? What problem does it create to keep the coolant going through the core? Getting the cable to toe control valve with the added wire is a bit tricky. I'm even thinking of just having the control valve on the hose not connected to the cable, then just shutting the valve during the summer and opening it in the winter manually. What do you think?

 

[DirtDonk]

Unless your heater box is fully insulated and the damper door is capable of completely shutting off all hot air from the core, you're in for a very hot summer (and unhappy passengers!) if you leave the coolant fully flowing all the time.

Better to install a valve and manually open and close it as you described.

Best still though, is to install it fully functioning with the cable. Many have done just that even with the EFI hard tube setups and are just fine.
Some heater tubes are harder to work with and around than others, but sometimes it's as simple as cutting off an end. Or it could be as complex as setting up your own fancy hose routing to take advantage of the cable.

But it's been done many times.
Here's one:


Paul

 

[Steve83]

EFI swap... What problem does it create to keep the coolant going through the core?

Using the older blockoff valve (2 nipples) on an EFI causes the coolant against the gauge sender AND the ECT to become nearly stagnant, causing false readings. That's why Ford changed to the bypass valve (4 nipples) which allows coolant to continue flowing past the sender & sensor, but NOT through the heater core.

I'm even thinking of just having the control valve on the hose not connected to the cable...

There are many JY vacuum-control valves you might conceivably connect to that cable to control the bypass valve, but until you figure that out, you can just manually connect or cap the vacuum line as needed. That's what I do.

Another option is to try to mechanically connect the cable in place of the bypass valve's vacuum motor.

 

[4x4man514]

subscribing for that heater hose routing!

 

[904Bronco]

Explorer cooling tubes...
This is the hose you need: NAPA #11070 Heater hose (Gates #19070)
You cut it in three places, blue tape is in approximate locations.
This is the heater control valve: NAPA #660-1140 Heater control valve (Murray #74628) Identical to the Plastic Bronco one sold by the Vendors, except that it is reverse of the typical Bronco flow.
Please note that on a Ford SB water comes out the intake manifold and returns to the water pump. The valve is positioned to stop water flowing into the heater core. (Explorer cooling tube hose to Water Pump is obsolete. Use the hose for a Fox body Mustang 87-93. Cut to fit after you mount the Alt/tensioner/idler pulley bracket)
This is approximately what amount of hose is left over...
This is where you need to reposition the heater control valve cable hole (3/4") Just above the heater box, but below the Explorer ECU.

As stated above, there needs to be water flow in the cooling tubes when the valve is closed. Or the ECT does not get a correct read on coolant temp. On the 96 Explorer tubes (pictured) there is a short section of Heater hose between the two cooling tubes. Later tubes you need to loop those two small nipples with a section of hose.

Doug.

 

[Rustytruck]

Very Good job Doug this could solve allot of headaches for some conversions. Thanks for sharing.

 

[4x4man514]

now thats a great bunch of info thanks! i think my tubes point straight at the firewall. so either i will have to modify them or use some 90s. and im not sure if my tubes have that crossover, i cant remember what my tubes come off from. ill check tomorrow, is your motor a 5.0 or 5.8? mine is a 5.8,

Thanks a bunch!

 

[House]

Great info Doug, cool to revive a six year old thread!

 

[904Bronco]

Great info Doug, cool to revive a six year old thread!

6 years ago I didn't have the answer...

 

[904Bronco]

Mine is a 5.0

If your tubes are straight then they are probably Mustang...
Hint one tube is 3/4"? Then use the Thermostat by-pass hose to start with. It is a 90* and 5/8 x 3/4 for the feed to the heater control valve.

 

[4x4man514]

I looked today and my tubes don't have a bypass neither. So I'm not sure if I shouldn't look for other tubes. Kinda sux cause mine were chrome and perty. Lol

I know the 5.8 is a little taller though so I'm not sure if the upturned tubes would be too high though.

 

[lars]

For what it's worth...

When I was putting together the last pieces of my 408 (AKA a 351W) last year, I bought this Explorer 5.0 heater tube: https://www.ebay.com/itm/3224101577...d=link&campid=5335857059&toolid=20001&mkevt=1

That outfit also sells a version that doesn't include the ECT sensor: https://www.ebay.com/itm/3240524649...d=link&campid=5335857059&toolid=20001&mkevt=1

To use it, the bushing that screws into the lower intake is also required, so I bought one of these: https://www.tascaparts.com/oem-parts/ford-connector-f4tz9n437a

The tube set I bought off Ebay featured a small u-shaped steel tube that short-circuited from one main tube to the other, thus accomplishing the bypass necessary to keep the ECT happy. My previous Explorer 5.0 tubes had small nipples on the tubes, I used some rubber hose to connect them to accomplish the same thing.

On my new engine, the bent tubes at the back got close to my firewall than I liked, but it didn't take much bending/massaging to get them to clear. The ones on my 5.0 required more work to get adequate clearance.

I don't have any good photos showing the tubes up close on my install, but the photo I have does show the heater hoses, which have plenty of clearance to the firewall, hood and fenderwell.

 

[4x4man514]

For what it's worth...

When I was putting together the last pieces of my 408 (AKA a 351W) last year, I bought this Explorer 5.0 heater tube: https://www.ebay.com/itm/3224101577...d=link&campid=5335857059&toolid=20001&mkevt=1

That outfit also sells a version that doesn't include the ECT sensor: https://www.ebay.com/itm/3240524649...d=link&campid=5335857059&toolid=20001&mkevt=1

To use it, the bushing that screws into the lower intake is also required, so I bought one of these: https://www.tascaparts.com/oem-parts/ford-connector-f4tz9n437a

The tube set I bought off Ebay featured a small u-shaped steel tube that short-circuited from one main tube to the other, thus accomplishing the bypass necessary to keep the ECT happy. My previous Explorer 5.0 tubes had small nipples on the tubes, I used some rubber hose to connect them to accomplish the same thing.

On my new engine, the bent tubes at the back got close to my firewall than I liked, but it didn't take much bending/massaging to get them to clear. The ones on my 5.0 required more work to get adequate clearance.

I don't have any good photos showing the tubes up close on my install, but the photo I have does show the heater hoses, which have plenty of clearance to the firewall, hood and fenderwell.

what intake do you have on your 408? i bought one of those tubes and it wont clear the #1 injector on my lightning intake. this is really kicking my butt. my mustang tubes clear fine but they are straight at the back and dont have that small bypass tube.

 

[lars]

That's a Trick Flow R upper and lower. Interesting that it won't clear the injector. I was originally going to use a Lightning lower/Explorer upper combo, with an Explorer fuel rail. It cleared fine. Got a photo? I'd share one of mine but unfortunately the engine is out due to a scored piston, a topic for another thread.

 

[4x4man514]

Ouch that sux. You sound like me. Im nursing a wiped out camshaft on a big block in another truck.

The silver mustang tubes clear fine. But the black explorer ones wouldn't fit even without the injector. It would have the tubes. Cock eyed instead of parallel to the valve covers.. Maybe the threaded hole is locked in a different place.

 

[DirtDonk]

Is there a critical dimension that you can’t compromise that would keep you from “kinking“ the tube as it comes out of the fitting some more?
Just wondering if a tighter bend there would allow you to angle it outward more at first and then still keep it parallel to the valve cover.
Might even make fitting hoses at the back and easier.

 

[4x4man514]

Is there a critical dimension that you can’t compromise that would keep you from “kinking“ the tube as it comes out of the fitting some more?
Just wondering if a tighter bend there would allow you to angle it outward more at first and then still keep it parallel to the valve cover.
Might even make fitting hoses at the back and easier.

i was thinking about that, the only solution i can come up with. i dont know how easily those tubes could be bent without kinking. it might cause an issue with the back bracket but maybe it could be bent too. i wish there was just a bolt up solution but its starting to look pretty grim ill get that lucky

 

[lars]

Ouch that sux. You sound like me. Im nursing a wiped out camshaft on a big block in another truck.

The silver mustang tubes clear fine. But the black explorer ones wouldn't fit even without the injector. It would have the tubes. Cock eyed instead of parallel to the valve covers.. Maybe the threaded hole is locked in a different place.

Wow. Interesting. What kind of lower intake?

 

[4x4man514]

Wow. Interesting. What kind of lower intake?

its a lightning upper and lower. i cant understand what the problem is. unless i just got a bad tube but this isnt the first one ive had that didnt fit

 

[DirtDonk]

Going all manly on it without actually kinking it might involve some craziness like capping off the open end at the rear (with something very strong such as a soldered on end) then filling the whole thing with sand or water and then plug the remaining open end with a threaded cap.
Then bend it to your hearts delight with some kind of a jig and hope the sand or water filling helps it keep the form.
Would still be nice to have a die, but that might not be impossible to find on Amazon.
Or even at Home Depot if it fits like a half inch die.