New motor...header temps

[TXBronco 67]

I had a new 302 built basically back to stock. I have edelbrock intake, 1405 carb, msd ignition and wires, and tbp ceramic headers. after break in I am noticing the left bank is running a bit hotter. One of the exhaust ports is 440 deg f, the others are 285 to 310 and fluctuate, which I assume is normal. The 440 concerns me. Bad wire, plug, distributor point? What are your thoughts? Thanks!

 

[Broncobowsher]

There was an article in hot rod recently that dealt with exhaust temps. They really didn't care what the idle temps were. But apparently you are. By chance is that the cylinder that has a vacuum port on it? Do you have the PCV hooked to that port instead at the base of the carb? (where the PCV can be evenly distributed to all the cylinders)

 

[jw0747]

Did you rebuild it or an engine builder? If an engine builder what does he say about it? Personally exhaust temp has never been a concern.

 

[TXBronco 67]

No pcv hooked up at the port. I've not spoken to the engine builder, but I will. It's good to hear I likely don't have anything to worry about. Thanks!

 

[broncnaz]

Its going to be hard to get much useful info off idle exhuast temps and coated headers. There are a lot of varibles to contend with. Coatings can be thicker or thinner in/on certain tubes, idle AF mixtures tend to be richer and fuel distrobution can be sketchy at idle RPM's. exhuast ports and header tube differances can cuase different readings as well. ignition timing will cause differances although thats uusally more overall not to indvidual cylinders. Also whatever your using to take readings may be a factor. IR guns dont always read correctly especailly if you are trying to read a shiny suface.

Higher temps mean leaner AF mixtures I wouldnt say your to lean but that one cylinder may be leaner than the others could be a fuel distrobution issue or a vacuum leak in that cylinder.
But again tons of varibles to consider even more than I eluded to. If your overall tune is good to go then you should be fine. Otherwise you could be chasing a ghost at idle speeds.