Idea for EGT location comparison

[DennisG01]

Currently my EGT probe is in my downpipe, but with the engine out I am taking advantage of the ease of install and installing a new one in the manifold (I'm leaving the old one in the pipe). This gave me an idea - we typically hear that the difference in temperature betweeen these two locations is about 200*, but to the best of my knowledge, a direct comparison (same engine, same operating conditions) has never been done.

How about this: A dash-mounted switch that will allow me to instantly/on-the-fly switch between the pipe and the manifold probes.

Is this a good idea? I'd be willing to do this for comparison's sake (if it's not too time consuming), if someone can help with the specifics on how to do it (as long as it's not to costly).

[Craig M]

I know of a few who have EGT gauges on each "bank", left and right manifold. For operating a vehicle that is a beter use of two temperature probes. It would be nice to see if the 200 degree "difference" is really correct. The information would be nice to kow, but other than that it will not help you very much as far as operating the truck.

[DennisG01]

I agree, as far as actual operation goes it doesn't mean anything. But if it's an easy and cheap thing to do, it would be interesting.

[More Power]

Somewhere in this board is a post from someone who did the EGT comparison, between the manifold and the downpipe pyrometer location. If I remember correctly, he saw up to 350 degrees difference between the two - under certain conditions. Most likely, this was a high load situation. I would expect that the lighter the load on the engine, the less difference there'll be.

Jim