GETTING HOT!!
 

Hey guys, I need a bit of advice. Weekend before last I used my truck and a 20' gooseneck trailer to help a friend move from GA to NC. The gross vehicle weight was just over 21,000 pounds. Now, keep in mind that it is August in the south I expected temps to get a little high, but my water temp was riding at between 220 and 230 the whole way and was approaching 245-250 pulling the hlls. My EGTs peaked at about 950 but stayed in the 600-800 range for the majority of the trip. I'm runing a 12v Cummins out of a 1992 El Dorado bus (40 passenger bus for American Airlines). Although it is a '92 it has the P7100 inline fuel pump. Is it just me or do these numbers seem a bit high? Some other information that might help: I am running 4 10" electric fans with a shroud, The motor is turboed and intercooled using the turbo and intercooler that was in the bus. I can't think of anything else y'all might want to know. Thanks in advance, Kenyon.

your EGT's are in the clear and i would say relatively low for a 21k pound load. Very good EGTS. as for your coolant temp yes that is hot, esp with 4 10in fans runnings. check for air pockets, you may be running water only rather than a antifreeze solution which also helps to cool, most likely your thermostat is stuck open which never allows coolant to cool down since its always flowing. IF it is stuck open then it will take your truck longer to warm up.

That makes sense. I'll give it a shot. Unfortunately it will be a while before I know whether or not it worked because I work less than 3 miles from my house so it barely even gets warmed up by the time I get there (Another sign that maybe the thermostat is staying open). Thanks for the advice. I just thought it was weird that it was getting so hot. Typically 12v guys are complaining that their power plants never seem to warm up. Leave it to me to be different!

Is your pyrometer before or after the turbo?

My pyrometer is about 2 1/2" down from the exhaust side of the turbo.

So that means your exhaust temps were peaked closer to 1250 or 1300 which is pretty warm because you should add 200 to 300 degrees if your pyro is after the turbo.

So, I guess the next question is: How do I cool this pig off? 21,000 pounds isn't too much for a 12v is it? It IS stock for the most part as I am not too sure what to do to it to get more power, but on the flip side of that, doesn't more power usually mean more fuel, which in turn means more heat? The intercooler, radiator and turbo were all taken directly out of the bus and installed in my truck so I would assume they are sufficient, right? Would Tyler Smoot's thoughts on a stuck thermostat cause sky-rocketing EGTs? Like I said before, I am learning as I go, but I don't wanna learn the hard way. I'd rather learn from your mistakes than have to make my own. Thanks for the advice!

I think you might have some restriction in the radiator or the cac( if in front) could cause some air to be blocked out a bit...

work for a bus company ... love these little busses :tu:

Yeah, my firsyt thought was that maybe some mud or something had caked the intercooler and was preventing air from even getting to the radiator, but when I stopped and checked it out everything appeared to be clear. I even looked between the intercooler and radiator to see if maybe leaves and debris had somehow built up in there but that too was clear. Also, I failed to mention in previous posts that when we would take an exit the water temp would almost immediately drop down to 210 and the EGT would drop down to 500. I will get after it with the hose and make sure all of the fins on both the intercooler and the radiator are clear, thanks for the advice.

I had a 92 and it would run warm on long pulls but never could figure out why so I got rid of it hopefully you can figure out the problem.

Check your water pump. Sounds like the flow may be slow. Sometimes the fins break off or could be plugged with foreign junk.

Assuming your cooling system is in good shape, I believe you do not have enough fan. Or with four fans is possibly one is defeating the others due to turbulance or vortex effect of the fans working against each other . are your fans pulling or pushing?

passing the air too quickly over the surface of the radiator actually has a heating effect on the metals surface in that heat transfer cannot happen efficiently.
or as happened to me on a long pull with stock trailer out of parma ID, i lost one of my electric fans and did not know it.
I use two taurus fans in a '94.
one automatic, with thermostat, the second is manual.
i can see 230 on a hot day and a very long pull, but never more than that. 230 will not hurt these engines if its short term.

All four of my fans are pullers and installed on a shroud that I made out of a sheet of aluminum. A few things that I have noticed are: 1) When I kick the fans on the volt meter drops from 14 to about 12.5. 2) My boost has NEVER gone over 17 PSI, I don't know jack about boost, but from what I've read, that ain't much. 3) Back to the possible alternator weakness, when I kick the fans on (or the air compressor) while driving on the freeway I can actually see the fuel pressure drop (I have the FASS system). The alternator is relatively new, but ever since I put it in the belt has squealed for about 10-15 seconds after start up, then it also does it if I kick on fans or air compressor at an idle. It never squeals at anything over 1000 RPMs but that may not necessarily mean it's not slipping, right? Do y'all think it's possible that the alternator could be the root of all evil and the cause of all my troubles? That would honestly make my day 'cuz that would be a simple fix, but I don't wanna buy a $400-600 alternator and have the same problems. I went through and cleaned all the fins in the radiator as well as the intercooler, there wasn't much of anything in there, but it's a little cleaner now. Thanks for all the help!

do the fans have their own individual shroud that is pressed up to the radiator surface?
or does the fan share a common plenum with the other shrouds?
in essence is your shroud an open plenum sealed only at the outer perimeter?

Great catch ... could not be pullin through the radiator but just off the surface ... good thinking here .... they all 4 need to be individually seperated so that they will work @ maximum effecency ...... :humm:... what else ...... and the alt sounds like its too small ... might think about using a 2 battery isolator .....

2 batts for the usual and 2 batts for the fans and pump ... seperated by an isolator and will hence use the batterys as a buffer between the alt. and the device being opperated ... would be a little complicated to think but easy to set up .... just wire fans to 2nd set of batteries and the comp to the 2nd set also .... then main charge wire from the alt goes to the isolator in ... and then two charge lines one to the primary set and one to the secondary .... and most likley there will need to be a load indicator control wire if im not mistaken ..... :humm: