header temp

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Ironmike

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I kinda felt like my engine "lost a step" late last summer, my bud's think I'm nuts, and I could be wrong.
Everything perfect...valve adjustment, timing, carb. Plugs all look great too.
One thing bugs me though. After a nice "spirited" drive, with the car idling my number 1 cyl seems cool compared to others. With an infra red temp do hickey, #1 header pipe is running around 190 degrees. all others in the 240-280 range.
Is this just an LA motor thing or is something amiss?
 
Check comp. on that cylinder may have lost some compression. You may be not always firing on that cylinder if you have a radical cam its not always easy to notice a erratic misfire.
 
The end cylinders always run a little cooler but generally not just 1 end cylinder and not that much cooler. Temp that low sounds to me like it isn't firing properly. How does #1 plug look?
 
try changing the plug and wire. if you are using the cheap radio suppression wires they sometimes burn out inside. spiral core is the best suppression type wire.
 
tighten the intake bolts around that intake runner,also could be a fuel dist problem inside the manifold remember every thing is a comprise for best balance,also check for carb mounting bolts loose, then take it out and run it wide open then check temps again.
 
That's not a tremendous difference especially given the airflow over the tube and position of the #1 header pipe. #2 has the alternator in the way, the others are tucked next to each other or have components or body near them. Remember you're reading the surface temp - not the gas temp.
 
With good compression, I would be checking for a valve issue on that cylinder, like in a broken valve spring coil (could be an inner coil), and a soft lifter if you are running hydraulics. Something weak in one cylinder's valve train will drop the HP enough to be noticeable.
 
moper said:
That's not a tremendous difference especially given the airflow over the tube and position of the #1 header pipe. #2 has the alternator in the way, the others are tucked next to each other or have components or body near them. Remember you're reading the surface temp - not the gas temp.
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So, maybe run it a short time with the fan off?
 
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