Does anyone know if you can do away with the heat riser valve on the exhaust.
If not, is there any suggestions for a alternative approach.
It has a leak when the valve opens, i have put 2 on it and the same thing happens every time. Do they make one without the valve and if so where can i get one. Both ones i put on were new.

Thank you,
Bobby

 

C5TZ-9431-A = The left exhaust manifold is made especially for the heat riser valve on 1965/67 F100/350 352's and 1973/74 F100 360's / Marked: C5TE-9431-A / Obsolete

 

My truck has run just fine for years without one. I kinda suspect your will too.



John

 

Supposedly the whole raison d'étre for a heat riser was simply for certain narrow conditions and temps, just over freezing to say about 40F.

What happens, in cold damp weather the carb will sometimes ice up. Have seen this happen and it is pretty strange.

Anyway just let it warm up a little while longer in colder weather. The engines that have Rams horn manifolds don't have any heat riser at all, btw. Don't sweat it.

 

As John says, you really don't need that heat riser, but to eliminate it isn't just a unbolt and throw away job.

You will need a left hand exhaust manifold for a 390, or for any of the engines not mentioned by Number Dummy. Your exhaust manifold has a flat face to mate with the flat upper surface of the heat riser valve, whereas the later manifolds have the bottom belled out or cast to accept a regular exhaust gasket, the one that looks like a doughnut.

You will also need to extend your exhaust pipe on that side by the length of the valve, too.

These heat riser valves leak out the holes for the flapper almost new. I am guessing that if that is not your problem, then it is where it mates to the exhaust manifold. You might consider removing the flapper on the inside, and using some J-B weld or similar compound to seal the holes and the upper mating surface.
That is what I did, and it worked fine.

This would save a lot of trouble, if it works.
Of course, it might create more trouble, too!

Hope this helps.

 

Like Banjo says and FWIW they have the same number on them so don't rely on that for correct ID.
Eric

 

No heat riser valve:

C8TZ-9431-B (replaced C8TZ-9430-A) .. Left Exhaust Manifold-Use without heat riser valve / Marked: C8TE-9431-A or B / Obsolete

Applications: 1968/72 F100/350 360/390 / 1973/74: F100 390 & F250/350 360/390 / 1975/76 F100/350 360/390.