intake manifold heating up

[sidewalkman]

Hi Guys, on the front of my intake, left side I think, the intake manifold gets so hot it cooks my high heat engine paint off, but only there.

I read there is a water jacket or something in front of the carb, could there be a blockage or something?

[simplyconnected]

I suspect two causes. You need to know how coolant flows through your engine.

It starts at the water pump, flows through and around the cylinders, continues up the back of the block into the head, then coolant flows forward through the head back to the front of your engine and across to the thermostat. Both sides follow this route independently until they meet at the thermostat.

If your heat riser valve is stuck shut tremendous BTUs of superfluous heat must be conducted away by the coolant system. We normally see steam created where coolant flow is insufficient. Steam WILL come out the overflow.

I suspect you have a problem with the exhaust crossover which goes under the carburetor, not the cooling or air/fuel ports. This crossover gets hot. Check your heat riser valve. - Dave

[sidewalkman]

I suspect two causes. You need to know how coolant flows through your engine.

It starts at the water pump, flows through and around the cylinders, continues up the back of the block into the head, then coolant flows forward through the head back to the front of your engine and across to the thermostat. Both sides follow this route independently until they meet at the thermostat.

If your heat riser valve is stuck shut tremendous BTUs of superfluous heat must be conducted away by the coolant system. We normally see steam created where coolant flow is insufficient. Steam WILL come out the overflow.

I suspect you have a problem with the exhaust crossover which goes under the carburetor, not the cooling or air/fuel ports. This crossover gets hot. Check your heat riser valve. - Dave

Thanks' Dave, where is the heat riser valve? Car hasn't been steaming though, runs in the top 1/4 of the gauge consistently.

[newyear]

Allow me-I believe the heat riser valve is on the passenger side of the exhaust system between the exhaust manifold and the exhaust pipe.
Regards
Peter

[sidewalkman]

Allow me-I believe the heat riser valve is on the passenger side of the exhaust system between the exhaust manifold and the exhaust pipe.
Regards
Peter

Right, I can buy a delete piece, any repercussions on deleting it?

[newyear]

The only repercussion I can think of is that initial warm up would be slower, especially in winter.If yours is removable and cannot be freed off, why not replace it with a new item.
Just checked on availability.Not a cheap item to replace(Circa $86) and I don't see one listed on RockAuto.The shop manual recommends freeing stuck valves with a penetrating oil and graphite mixture.

[simplyconnected]

I'm a big fan of, gutting the original. Yes, you can replace with an OEM part or a spacer to replace heat riser valve.

I simply cut the guts out of mine with a torch, leaving the outside looking stock. That results in a clear opening for exhaust to flow out the pipe.

Many restorers (including myself) use a shield on the intake manifold to block exhaust from crossing over to the LH side. I use a simple shim stock to shield the intake manifold gasket, cut in an oversized rectangle. Only one side needs to be inserted. The shield may be removed later if desired (but I never have).

"Delete spacers" sell for US$20 at tee-bird.com in Pennsylvania. I believe their part number is, 9A435A, but call them and verify the 2" size with Bill at 1-800-423-3723. - Dave

[sidewalkman]

Thanks Dave, this winter I'm thinking I might add headers, just for the rumble, I already have 2.5" exhaust. I'm not so concerned with keeping everything original as it's not a convertible or highly optioned car. (roll up windows) I want dependable driver.