8v 71 exhaust temps

[eddiepotts]

I was checking the temps on my manifolds and found one side was at 170* and the other was 140*. Can this be right or a problem. I know when I would ballance a natral gas engine on large compressors we would adjust fuel until all cylinders had same temps. I have a whole side with 30* differance

[johns4104s]

How did you check the temperature?

[eddiepotts]

With an infrared temp gun at each port

[luvrbus]

Eddie, pull the valve covers and check the pins in the governor rod if they do not spin free one injector or more are out of adjustment. 
30 degrees is to much should be + or - 5 degrees run the rack and set the injector timing should correct it


good luck

[eddiepotts]

Thanks I can do that. Does anybody have a link that explains how to set the rack. I know I can do it. I just neeed some instuctions.

[bevans6]

It's in the tune-up section of the factory manual, which you really should have.  you need the injector timing gauge, 1.460" is the standard spec for 8V71.

real simple overview - Tie off the speed control lever to idle.  Place the stop lever in the stop position.  Adjust the exhaust valves first. 

Next rotate the crankshaft until the exhaust valves on the cylinder being adjusted are fully depressed.  Measure the height of the injector with the gauge.  Adjust the pushrod until the height is correct.

A timing gauge can be had from these folks:  https://handsontools.3dcartstores.com/Kent-Moore-J-1853-Injector-Timing-Gauge-1-460_p_20848.html

The have them in stock, I got one last week.  They have a bunch of other sizes if you don't want the 1.460"

Brian

Brian

[JohnEd]

Eddie,

What a great find in information.  As I understand this:  were both heads operating at the same temp.....that in itself would not necessarily PROVE that the rack was in adjustment BUT if there is a substantial temp difference then the rack adjust is probably needed.  Am I right here?

I thought you could shoot the temp of each exhaust port and look for even temps....hot was rich and too cool was lean.  If they were all consistent except one then maybe only the rack needs run on that single cylinder then.  Would that be cheating?  I think I would tend to want to set the ONE to the settings of the adjacent cylinders to get it even.

You can get different temps from different thermostats.  Swap your thermo between heads and see if you get identical, and I mean identical, results. If so then the thermos are good and balanced. If not....replace both.  Then check and swap again for all the info at the start point.

Your radiators might not be good.  See if both rads drop the temp the same number of degrees.  Input temp minus output temp.

There seems to be two complete cooling system on these things with a common water pump.  Go figure.  Both must be working and working well.  A single temp gauge and a single shut down thermo seems to be under protecting a really expensive device.

And all this from a guy that never turned a wrench on one of the beasts.  I know that you do have a serious problem and you can take that to the bank .  Clifford said it, but , given the stakes, I thought there should be a lot more arm waving and shouting.

HTH,

John