I want to find out which cylenders run the hottest .I'm trying to decide where to put the pyro TC in the manifold .I can't decide.I feel so lame!

 

If you have access to an infrared laser thermometer, (they are less than a $100.) you can point it at each cylinders exhaust outlet from about a foot away and find the temps on each cylinder on the manifold. There are lots of posts on here telling which cylinder everyone thinks is the hottest. If you have injectors that aren't perfectly balanced in flow, it could be any of the cylinders. It also depends on which cylinders are combusting the best. Some cylinders get better air flow than others because of the restrictive intake. ks

 

An infrared gun will only tell you which cylinder is warmer at an idle. Its not going to tell you which ones are hotter under a load unless you sit under the hood while you are running down the road. Its a good tool to diagnose injector and fuel delivery problems but meaningless on the road.

The back 3 cylinders run the hottest with the #6 the worst. This is due to their position in the engine compartment, distance from the water pump, and air and water restrictions in the rear of the block. If you are just running stock and no heavy towing it doesn't matter as much where the probe goes, but, if you start working it hard or BOMBing then the back three cylinders are the best place to monitor.

 

Ditto that. 5 & 6 run about the same for me and can be almost 200*F hotter than the rest at WOT depending on how much power your pushing. You have to put the probe right outside the exhaust port on the head so it catches the blast when the valve opens to see the real difference. Down in the collector, it has cooled down already and mixed with cooler exhaust from #4.

 

start with your thumb and finish with a pinkie, the one with the worst burns is the hottest. that will leave you a cylinder short, so you decide which finger on the other hand to use.

the water passages are pretty well balanced on a ctd. straight engines especially are balanced well for cooling/lube. each gets equal air due to the intake manifold plenum design, the outer cylinders have longer to go on the exhaust side, but less restrictions compared to #3 and 4 where they join together. dont know, some of the sled pullers are tapped at each cylinder for data collection, maybe on of them could chime in here.

 

Rear cyls on almost any engine are the hotter ones.

 

I ran my truck ip the steepest hill around today,& raced out under the hood,& infra red gunned the exh. runners.Got the fopllowing results.
1-3 ran pretty even @ about 550*
4& 5 were hard to differentiate but got about 600*
#6 showed 650*.
I ran down,& back up again,& got the same.So I drilled & taped the exh.1.5" above the turbo mounting flange,in the 4-6 (rear) port.