CHT temps, individual cylinder differences? Options

[falcor75]

For those of you that are running 4 CHT sensors under the plugs, what differences do you see between the cylinders?

Whats your typical temps for each cylinder with:

A: Engine warmed up sitting at idle for a minute or two.

B: Engine warmed up, cruising at 50-55 mph in fifth gear.

[jd74914]

What is your target AFR? Or do you have a screen shot of your map?

That's a pretty big difference in fueling at idle given the airflow differences. Assuming you are at lambda = 1 for cyl. 1 airflows, you'd be at about lamba = 1.3 for cyl. 2 at idle. That's certainly enough fuel to cause some additional cooling and result in those lower temperatures.

You could see lower flows if you have some valve adjust or pushrod length issues (not opening enough) or a flat cam lobe. I'd guess the cam is OK since your motor is pretty new.

Were your injectors all flow mapped or checked? I've seen some new injectors pretty far off the mark. If they haven't been tested it might be interesting to swap them between cylinders and see if the temperature mapping moves.

[Dave_Darling]

You could see lower flows if you have some valve adjust or pushrod length issues (not opening enough) or a flat cam lobe. I'd guess the cam is OK since your motor is pretty new.

Another point arguing against a flat cam lobe is that opposite cylinders share cam lobes. So if the left-rear intake had a cam lobe problem, the right-rear intake would have the same problem.

Lifters, of course, are specific to each side.

--DD