Posted by Greg Coffin [172.68.34.7] on Friday, December 29, 2017 at 00:54:47 :
The 318 I have in the 6x6 does not have a heat riser control valve (or whatever it's called) on the exhaust manifolds. The engine was set up this way when I pulled it out of the donor vehicle. A friend told me that the valve closes to send heat under the carb, then opens when warm and stops pushing exhaust. He said the engine would run fine without a valve.
Today I noticed that the intake manifold is running hot in that area (see discoloration just above the PCV valve). I don't think this is good. Can I block the passage under the carb to stop the heating (via the choke heat riser opening), or do I have to get new exhaust manifolds?
Follow Ups: