Thermal Imaging for engine tuning and troubleshooting

[John S]

Hi All, i am working on a theory that thermal imaging can be used as a tool for tuning and troubleshooting 4 stroke engines. I am in the beginning stages of my research but I wanted to try and get the opinions of others that are most likely more knowlegable then me in engine theory.
My goal is to determine if thermal imaging could be a usefull tool especially during dyno tuning of fuel injected engines and I am basing this on exhaust gas temperatures (EGT) in particular.
It is my belief that there are two things that will affect exhaust gat temperatures;

1. Timing
2. A/F ratio

With many of the modern engine management computers both of these units can be controlled either globaly (all 8 cylinders) or individually. This would also only work with a Sequential MPFI system since there is no direct way to control fuel metering into an individual cylinder with a TBI or batch fire system.
It is also my belief that a lean mixture will cause a higher EGT and conversly a rich mixture will show lower EGT's.
What i am unsure of at this point is what role timing plays in both cylinder temp and EGT so if someone can elaborate on that it would be a good start.
Here is an image I took today of the right bank of my engine at operating temperature. This engine has only seen one dyno tuning session but from what I see it appears that there is a lot of room for improvement to balance all the cylinders. Another question is what would be a good baseline? For example, there is a Delta T ( temp difference) of 206.2* between cyl 4 & 6. Would it be safe to assume that the hottest/leanest a cylinder can run without any detonation is going to derive the most useable power?



In the image above it is quite apparent that there is a huge difference between the hottest and coolest cylinders. All things being equal and timing remaining constant would adjustments to the pulswidth of the cylinder injectors bring the cylinders into a more uniform heat pattern and increase or at least optimize power in the process?


Obviously since this is only an idle test, data would have to be gathered at various rpm and loads. This is where a dyno comes in but I have been unable to get any dyno time donated to do some testing. But I am still working on that.



Sorry about the long post but I am still gathering my thoughts and working out some details on this whole thing.
And in case anyone is wondering about the equipment I am using the IR camera I have is a very high quality ($35k) industrial camera.