Running too hot, or not?

Richard Reau

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Hi fella and fell-ettes,

My 65 New Yorker is on the road, and seems to to be running pretty well. There is some random pinging, so I got some 93 octane non-ethanol gas in it, and added some octane booster. Still have random pinging.

SO, I bought one of those laser thermometer thingys from Harbor Fake Tools, and the thing is reading as follows: upper radiator hose 170F; intake manifold under the air cleaner 335F.

I performed the same test on my 67 Newport 383, and got 170 at the upper radiator hose, and around 200 on the intake manifold.

That 335F reading sure seems high to me, but at idle with that reading, there are no outward signs of overheating.

Thoughts?
 

Knebel

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Intake manifold under the carb has the exhaust heat crossover. Thats why its so hot.

Measure upper and lower radiator hose see what the difference is!
 

Richard Reau

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Thanks Knebel, I'll do that. The 170F reading on the upper hose would make sense I guess, as there is a 170-degree thermostat. Does the 383 2bbl not have the heat crossover?
 

Davea Lux

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Check to see if your heat riser is free and functioning. If it is stuck closed, that could be the source of your pinging as the intake running hot will boil the carb and cause it to run excessively lean.

Dave
 

Richard Reau

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Thanks Dave, do you mean that valve on the downpipe that clanks sometimes? That valve on my Newport works well, but it appears to be frozen on the New Yorker. I am not sure if it is frozen open or shut. That tailpipe does seem to be exhausting though.
 

CBODY67

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From where the valve is attached to and rotates in the exhaust manifold. There is a travel limiter for "full open" (as it rotates CCW). Usually, they stick 1/2 open which is fine as everything still works.

When we had the valve replaced on the '66 Newport 383 2bbl, when the new valve was installed, its shaft was tight in the supplied bushing. The tech took a reamer bit on a die grinder and "clearanced" the bushing so that the shaft operated smoothly. I suspect that all of the OEM valves were installed a bit tight, which could well be one reason most of them "stuck".

Just some experiences,
CBODY67
 

Davea Lux

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Thanks Dave, do you mean that valve on the downpipe that clanks sometimes? That valve on my Newport works well, but it appears to be frozen on the New Yorker. I am not sure if it is frozen open or shut. That tailpipe does seem to be exhausting though.

If you are getting exhaust out of it, it is not stuck shut. Valve shaft should turn freely so that heat is applied to the choke spring. Heat makes the spring relax and open the choke as the engine warms up..

Dave
 
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