Increased airflow through grill

[brutpwr]

I always figured that air would exit from my Cowl Induction hood scoop on my 70 Camaro but may be it doesn't. I know when parked air does exit this area but maybe not at speed. I'll have to run some tests lol.

 

[cool_as_crap]

Do you have anything under the camper? It looks from the pic like its sitting kinda high compared to the truck bed, which might increase drag and contribute to your problem.

 

[88GMCtruck]

Hummmmmmm.

Interesting problem you are having. My first question is, which radiator do you have? I know most of them by that age went to the 34" wide radiator, but there are 2 and 3 row cores. I would make sure you have the 3 row. Also, if your truck has the transmission cooler routed through the radiator itself, I would ditch that and keep it standalone. Your transmission will run hotter than your engine to begin with, so it can contribute to that. It's likely the largest contributor to your rising heat, is the auto transmission. Also keep in mind your stock thermostat is a 195.

Now, I probably have about the most similar comparison you will find. I'm not lifted, but I have a 98 K3500 454 truck, although mine is a NV4500. It has a GMC grille, but I have a 32" LED light bar behind the grille so it's about the same as your chevy grille. I have a diesel bumper but there are fog lights in it so it's null. I have the 3 row radiator with internal oil cooler. 4.10 gears and 33" tires.

This is my old camper, and the heaviest I towed. Went from western WA to eastern ID over 3 mountain passes, in 80-112 heat with no problems, truck never went over 200-210 or so while running AC. This setup was about 18k gross.

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Since then, i've made a few changes, most notably a different camper, a cargo trailer and a whipple supercharger. This setup is about 15k

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With the whipple I'm running a 180 thermostat, and climbing long hills because of the boost and being non-intercooled it moves up to the 210ish mark, but that is about it.

 

[Supercharged111]

Try the free fix first. Remove the radiator and pressure wash the fins to blow out all the dirt and **** through the front. Blow out the AC condenser too. You'd be amazed at how much is packed in there. I first did this to my Corvette because it's pretty much mandatory for that bottom breather. Later when I had a radiator tank replaced on my truck, I did it there too. I never really saw a difference because cooling was never an issue to begin with, but I did get a lot of dirt out of the radiator and AC. I'd drop to a 180 stat as well, but then again I do that to most all my vehicles.

 

[df2x4]

I'd drop to a 180 stat as well, but then again I do that to most all my vehicles.

I agree with the cleaning suggestion, but these trucks really prefer the factory 195 degree stat. Dropping to anything lower without re-tuning the PCM to expect it will cause issues getting into closed loop. The computer will think the engine is still trying to warm up because the stat opens earlier than expected, and alter fuel delivery accordingly. I'd stick to a 195 degree.

 

[Supercharged111]

Uhh, no it won't. Closed loop happens long before 180.

 

[df2x4]

Uhh, no it won't. Closed loop happens long before 180.

I never said closed loop happened at 195...

What I am saying is that both my mechanic and my tuner have told me that unless you're tuned for a lower temp stat in these trucks, leave it alone. In older non-computerized engines, go for it.

Not trying to start an argument, every single time I mention this on here someone gets upset. If you want to run NO thermostat in your GMT400 go for it, not going to hurt my feelings any. Just stating what people far more knowledgeable than I have told me on the subject.

 

[Supercharged111]

That's stupid. It hurts nothing. A 160 keeps the oil a little too cool and will accelerate wear, but it'll still make more power. You don't need a damn tune to run a cooler stat. Go download some tuning software and see how these trucks are setup yourself before taking someone's word on the matter who isn't qualified.

 

[df2x4]

I think you're misinterpreting what I'm saying here anyway. I'm not saying that a low temp stat will necessarilly hurt a thing. It's just pointless, and will not gain you any power or other benefits.

But nah, I'll just keep believing Justin at BBP and my mechanic. Like I said, not trying to argue. You're entitled to your opinion.

 

[Supercharged111]

It keeps you farther from the fringe of detonation and gives you a "head start" if you will at keeping the truck cool when climbing a hill. My 93 Camaro dynos lower the hotter the coolant gets. You can watch it drop about 1hp from one pull to the next, starting at the 160 degree temperature of the thermostat. My "opinions" are based on facts.