To start, I've looked at and checked all the obvious or I wouldn't be asking. However we all have momentary lapses in genius as well...
ok so it's a 91 camaro rs. It has a bone stock brand new 454. New water pump, new hoses. New 4 core aluminum radiator. I've tried it with and without a thermostat. Basically everything is brand new. Fans are wired to ignition and don't shut off... car gets hot sitting still. Just climbs and climbs I shut it off at 230 and leave the fans run until it starts to cool on the gauge. I'm left guessing at this point. All work was done at a trusted shop with a mechanic who has built a number of cars over the years. I haven't got to drive it since it was assembled and it's starting to kill me! Anything advice or ideas are much appreciated!

 

Are you using the factory gauge? If you are I would check an aftermarket one or IR gun.

How hot does it get while driving?

 

I'm using an autometer mechanical gauge. And I haven't driven it yet. If it can't just idle and survive I definitely don't wanna risk traffic with it. Gauge is new as well and is reading writhing 5 degrees to the best an ir gun has shown me

 

maybe a blown head gasket.

 

Checked that. Pressure tested cooling system and held fine. That was my first thought even with a brand new engine

 

only other thing I can think of is maybe you are turning the electric fans on to late the the heat cycle. I have my first fan coming on at 160 and 2nd coming on at 180

 

Fans wired to ignition they come on as soon as the key is turned on and run constantly

 

one last thought make sure your radiator over flow is hooked up and has coolant in it, the radiator fill is below the thermostat housing and will have air in the system without it.

 

Yeah checked that. Like I said I'm pulling my hair out on this one

 

Are the fans blowing the correct direction?

 

Now there is something I haven't checked, you wouldn't think just idling it would make that much of a difference, but I suppose that's why they make them that way... I'll check that.

 

Some setups have to be either push or pull and wont work the other way. I am also just taking shots in the dark here.

 

something else you may want to consider is a tranny cooler, and as mentioned above fan direction is big a piece of paper will tell you if you are pushing or pulling seems like I remember making this mistake before

 

Probably should have said it was a manual tranny... but I will have to make sure the fan is going the right way. Sadly I only get to visit the car on the weekends...

 

Do you have the correct rotation water pump?

 

Yes water pump rotation is correct... had a thought maybe I'm wrong. If there is no thermostat in it, and the factory bypass hose is hooked up from the water pump to the intake manifold.... would it just be cycling the majority of the coolant there and not actually running through the whole system... any thoughts on that?

 

Does the cooling system pressurize?

 

The other guy had the fan rotation backwards.

 

Take some pictures of your setup and post them

 

ive never seen it run this way before, always when not running a heater core that passage has been plugged and blocked off. seems to me if ran the way you are explaining it would be recirculating hot water to the top side of the motor id try blocking it off you can pick up some aluminum plugs from auto parts store or brass from hardware depending on your preference Id use aluminum with aluminum.