I've been having overheating issues since I put my new motor in 2 years ago...after about 17 minutes of running the car creeps up to over 220-230 and I shut it off...can a rich tune (~10.8-12.8) make the car gradually overheat? I've put a new water pump, radiator and t-stat in it and still have the issue.

I don't drive the car more then just around the block because of the issue, so it stays under 2500 rpm the whole time. I know a lean tune can make a car run hot, can a rich tune do it as well?

I have the fans both coming on at 190*, and never had any problem until this new engine and cam. The cam is 23x-23x on 115 LSA, forged 370 with LS9 headgaskets and 317 heads.

 

Ive never had a car run hot when rich. If its lean it will heat up fast. Is this just idling it heats up? Or cruising? or both? Where is it 10.8:1 and where is it 12.8:1? How sure are you that your wideband is accurate?

 

You either have a problem with the tstat (not opening all the way) or you have a blockage/leak somewhere in your cooling system that's not allowing it to perform at full capacity.

And when do you see fueling that rich? Part throttle or full?

 

yeah you have other issues besides your tune. check the basics, t-stat, blockage, water pump, etc. are all the crossover pipes in place under the intake? a rich tune will actually burn a little cooler than a lean/stoich tune

 

Head gaskets on backwards could do that.

 

That's what I was thinking.

 

It overheats either way, just gets there faster when being driven. It's mostly 10.8 or so at idle, and jumps back and forth when being driven, but stays more around the 10.x range. I haven't tuned it well enough to put it back in closed loop, and when I pull some VE around the idle area's it goes too (16-17afr)lean when I start cruising around the neighborhood so I leave it open loop and rich at idle while trying to figure out this running hot issue.

I'm not 100% percent sure how accurate my LC1 is, it's got about 4000 miles on it and I recalibrated it when I put the new motor in around 300 miles ago.

That's where I've been chasing, I just put a brand new stat and waterpump in the last few weeks, and I stuck the garden hose in the rad and it flowed pretty well. The rad is a custom built 4 inch thick aluminum unit that is overkill and holds almost 2 gallons. The cooling system is the same setup I've run for 6 years now, and been on 1500+ mile trips with no issues on the stock bottom end. I went back and watched some of my old logs and it stayed around 190* all the time.

Car hasn't been WOT since I put the new bottom end in, all part throttle. I havn't been WOT or felt boost in 2+ years

the crossover is there, and I bleed the system through it

That's what I'm most afraid of, because I'm not taking the motor apart again. This is actaully the 2nd pair of LS9 headgaskets I've put on in the 300 miles I've put on the new motor, but it was running hot with the last set too. I'm 99.9% sure they are on the right way, the LS9's say "FRONT"(towards waterpump), right?

I had a lifter turn sideways in the lifter tray last year when breaking the engine in, and wiped a cam lobe so I just put this thing back together at the beginning of this summer. It's been one problem after another since I put the new engine in, I've worked through them all but this one is driving me nuts and if I don't get if figured out by the end of this year I'm putting the car back to stock, selling the parts and getting a C6Z.

Thanks for all your help everyone, I was hoping to hear a rich tune could cause it, but I'll keep my efforts focused on the cooling system.

 

Mine was over heating everytime i drove it and it runs really rich since no cats and no tune you could have air in the system Jack your car up in the front and let it run and check to see if ur stat is opening up and also check your fans I been dealing with the same issue pretty much iv got to take my lq4 back apart for another head gasket since i goofed up hope u get it fixed soon