352 running hot - where to start?

[KULTULZ]

Only mod from original is that I have added an A/C condenser but it is not connected - just sitting in place in front of the radiator.

The condenser may be affecting air flow through the radiator.

Remove it and with the engine running and warm, gingerly put the palm of your hand onto the front surface of the radiator. If it is cooler towards the center of the core, you have a blocked radiator.

If you plan AC in the future, you will need to go with at least the fan, radiator size, fan clutch, shroud (if so equipped) of an AC equipped BIRD of the period.

Make sure your GEN belt is tightened to spec and in good condition as a slipping drive belt will allow the water pump and fan to slip @ speed/load.

The suggestion of a collapsing lower radiator hose is very important as cheap off-shore hoses now are made from very flimsy materials. It should also have an expander coil spring to prevent it from collapsing at hard pull. The springs are available separately. Make sure it is SS or galvanized at best as they will dissolve over time if the coolant is not serviced frequently.

[Charles Nix]

Heat Riser Valve

Can anyone tell me where it's located and how to check it? I an going to start checking out the cooling system next weekend, component by component, but I no clue where or what this valve is or does. Thanks.

[jopizz]

It's on the passenger side between the exhaust manifold and exhaust pipe. You should be able to move the lever up and down. It's closed when the engine is cold to help it warm up and gradually opens.

[DKheld]

This one is out of the car but here's what it looks like.
Some common problems were that the vane comes loose from the shaft or the thermal spring gets either damaged or wears out causing the vane to stay closed.
No idea how you could test it in the car except to see if the outside weight moves when the car warms up but that still wouldn't tell you if the vane is loose.

Eric

[Charles Nix]

Heat Riser Valve

So,if it stays in the closed position for whatever reason, coolant doesn't circulate in the block? Should I just replace it to be on the safe side? By the way, thanks for the pictures. As "they" say, it's worth a thousand words.

[tbird430]

So,if it stays in the closed position for whatever reason, coolant doesn't circulate in the block? Should I just replace it to be on the safe side? By the way, thanks for the pictures. As "they" say, it's worth a thousand words.

No. No, no.

A stuck closed exhaust heat riser valve will cause extreme & unneccessary heat to build up inside the engine. This is caused by the blocked flow of exhuast gases in the passanger side exhaust manifold. This can often mimick an overheating engine...

-Jon in TX.

[Charles Nix]

Got it! I will be sure to check it out. This is VERY helpful and appreciated.

[simplyconnected]

Jon is right, a stuck closed heat riser valve will cause overheating AND a reduction in power.

Good pictures, Eric... The top pic shows a counterweight and a bi-metal spring. The counterweight pulls the valve shut when it cools, and the bi-metal spring helps to open the valve when it's hot.

Reach down the passenger's exhaust manifold and TRY moving the counterweight. If it's stuck, it is probably stuck shut. They tend to rust shut. Use lots of penetrating oil and a hammer to tap it back and forth until it works free. If it will not free up, leave it in the open position with the counterweight up. - Dave

[Charles Nix]

Heat Riser

Is there any reason not to just have a muffler shop remove it? In my climate, even the winters are warm (No. Central Texas). Was this the forerunner to block heaters used in cold weather climates?

[tbird430]

Is there any reason not to just have a muffler shop remove it? In my climate, even the winters are warm (No. Central Texas). Was this the forerunner to block heaters used in cold weather climates?

You can remove it.

In fact, most T-Bird parts venders even sell a spacer that can be used to remove the heat riser valve...

-Jon in W/Falls,TX

[simplyconnected]

I'm still wondering what condition his original was in. Was it stuck???

[Charles Nix]

Heat Riser

Once I get it removed this weekend, I'll post what condition it's in........sure hope this was the problem - or maybe part of it - and certainly appreciate the collective knowledge of the forum. I've received quite an education about my new Squarebird.

[simplyconnected]

I'm not suggesting you remove ANYTHING that works ok. Don't throw money and parts at your car unless it needs it.

This is a very easy part to check and it requires no technical skills. I still don't know if your part is stuck or not. Reach down and check it. - Dave

[jopizz]

I second what Dave says. Unless you plan on replacing your exhaust system I wouldn't remove the heat riser if it's working. You will more than likely snap off the manifold studs.

John

[Charles Nix]

Heat Riser

As I understood the information from an earlier post, just because the shaft turns does not mean the vane is opening. Is there any way to verify that? If so, I need to know.