It seems to me I'v heard of using exhaust gas port temps as a fuel/air mixture adjustment tool. I think they were using a non contact laser gauge as a tool. I'm trying to fine tune a 62 340HP with the correct 3269S Carb that has been rebuilt. Has anyone heard of this?
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Re: Beyond a standard tune up
stock carbs are jetted for sea level and you should reduce the AREA of the jetting 2% for every 1500 feet you are above sea level. any other means of tuning the carb will need a chassis dyno to get reading under load. -
TerryComment
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Re: Beyond a standard tune up
The measurements will vary considerably, based on the location of the thermocouple used. Refer to the attached discussion.
There is a very simple "rule of thumb" method, using an IR thermometer, which should put you in the ballpark. I have not actually used the IR thermometer method, as I suspect that it will not be useful as an A/F ratio adjusting tool. Some have claimed that the measured temps actually drop, noticeably, based on idle advance adjustment.
If you need to adjust your A/F ratio, I would suggest that you purchase/borrow/rent or pay someone who has a proper A/F ratio probe.
Joe
http://www3.fs.cvut.cz/web/fileadmin/documents/122Comment
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Re: Beyond a standard tune up
If you installed a thermocouple in the exhaust port with a temperature gauge in the cockpit and a knob to adjust the area (move a metering rod) of the cruise jets you could optimize the mixture, and you would be duplicating the "cruise tuning" used in some older light airplanes. I don't know if they still do that with modern airplanes.
Of course, you would need to know the optimum temperature for your engine.
VerleComment
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