saleach

Excellent observation and valid point! Kudos to the attention to detail. I found that when the fans kicked on there was no appreciable notice in temp decrease. I then realized that the fans were just pulling air from around the shroud instead of through the radiator. I remedied this by stuffing foam around the perimeter of the fan shrouding portion. Once i did this, i could see the temp drop once the fans kicked on. Keep in mind that this was with the AC off, with the AC on the temp decrease wasn't as noticeable. See attached picture.

Thanks for the replies, keep them coming!

King Tut

What happens if you just let it idle with the hood down in the driveway? Does the temp increase, fans kick on, temp decreases, fans turn off?

spdracerut

Despite your stack of heat exchangers, the car coolant temps should not be that high just highway cruising with A/C on in 90 deg heat. I tend to think there's still air left in your coolant system. The S2k is just notorious to bleed all the air out of the system. Even with coolant coming out of the bleed screw, I've still always had some air left in the system. The only way I've found to get all the air out is to take the engine to redline a bunch of times, where the changing engine speed and therefore coolant flow helps to burb the system. I always make sure coolant bottle is to the full level and usually it'll get sucked down to low as the air works its way out of the system. Another way you know the system is bled is you have consistent hot air. Of course, you have to bleed the system with the heater turned to full blast to open up the coolant flow to the heater core. I suspect that's where a lot of air gets trapped, in the heater core.

spdracerut

What does your vented hood look like? Also, I'd put a heat shield around the header or get it ceramic coated, just for general thermal management. There's a fair number of rubber hoses in the area of the header and the heat coming off it will cause the hoses to deteriorate faster.

afzan

What condition is your AC heat exchanger in? If it has tons of flattened fins and junk in there it can hurt air flow. Same goes for your other coolers in front of the rad

saleach

Correct, the fans cycle and the coolant goes down. I will double check again today with flashpro datalogging and get the actual turn on/turn off values and report back.

I agree and have had a hell of a time getting the system to bleed with the new radiator. I bled the system with the heater on until it was very hot and no air was coming out of the bleeder using the billman method after 3 times. I thought it was bled. Then, after going to the track i noticed high temps and tried to turn the heat on, sure enough, it was no longer hot. I came back and drained the coolant completely (it was 80% water, 20% type 2 and i was concerned about the boiling point) then refilled with type 2. Again, i bled the system, first using the funnel and bucket method, cracking the bleeder when the fans came on, then i let it cool, topped it off and bled again with the billman method. I even put a brake bleeder on the second port near the firewall. I have since driven it (redline, turns etc) and bled 5 more times with the billman method with no air coming from the bleeder and the radiator completely topped off. I believe it's bled, but i can't be totally sure.

I have a VIS replica J's racing Type V hood. I think coating/wrapping the headers is going to be my next move. They are set so far back that i do not think the vents make as big of a difference as they are set further forward and taper down towards the rear of the hood. I believe this should help with heat soak and will make the engine bay cooler, but i doubt it will result in a significant decrease in oil temps/ECTs. I could be wrong.

I really appreciate the continued responses. I feel like there is something i may not be considering in the setup other than the stacked exchangers. I may try vmounting the heat exchanger and oil cooler. perhaps the 220-270F oil temps being blown straight into the ac condensor and then radiator are what's causing it. I have already lost one engine due to what was suspected to be overheating (cracked rings cyl 3 braking off and deeply gouging cylinder wall and piston head). I don't want to lose the new engine as well. Any insight is appreciated.

afzan

have you considered moving your oil cooler behind the radiator?

MorngWoodStewie

By putting the foam in the areas you did. You might as well count that surface area that is open as inneficient as possible now. Your practically only cooling the fans circumference. Imo you would have better luck covering the cut outs. Edit: what you did was maximize the fans cooling ability but at the same time "cooling capacity" was degraded. That thing looks supa thick to! I wouldnt put all your eggs in the shroud, see bellow.

I also thought the same thing... 90* ambients arent that bad, atleast for streeting with AC on as well. Keep bleeding. The only way i was able to get all the air out was by using the back rubber nipple leading (to or from) heater on back firewall. Grab a rag folded up a bit and i wiggle till coolant comes, rinse repeat. Works wonders after you do the front piece. The heater And pipes leading to and from are some of the highest points of the system and IS what collect most the air.

Mrsideways

Best Radiator in the world can only do so much if your delta air temp is to high. Make sure the rad is getting some fresh air (ie your intercooler isn't to big). Also one of he tricks the racers do is to ditch the OE bypass and thermostat setup. put a bypass T-stat in the upper hose and block off the factory bypass under the intake manifold and remove the OEM thermostat. Car will warm up "slightly" slower. I had This guy make my bypass setup... http://www.ipsco.org/Custom%20Servic...g%20custom.htm

I'd also run a head gasket test if I were you. I might be that yo have a "SLIGHTLY" blown head gasket.

saleach

I have, similar to MOTOiq did. However, with the amount of heat soak in the engine bay, combined with the already weak airflow through the cooler, i figured the difference would be negligible. However, i think i have rationalized why it can't go where it currently is. (See next post)

I think you may be misunderstanding the foam. The foam is very thin strips (3/4" high by 1/4"wide) and it is only located on the outermost perimiter of the fan hole cut (like a circle) Airflow still can pass through the cutouts and through the radiator where the steel is still closed off. That way, air is forcibly pulled through the radiator when they kick on, but it is still allowing free flow through the rest of the holes at speed.

I have tried putting a brake bleeder on the rear nipple of the firewall and did get some air out of it. However, i can't say for sure if all the air is out. I thought i had all the air out before, but i didnt. I have bled it 4 times now and haven't gotten any air the last 2 times. Would the overflow tank take care of the small amount of bubbles remaining trapped in the system?


I think this is a good point, the temperature delta. The thicker radiator is not working for two reasons, 1, there is a higher temperature delta from the oil cooler in front of it (see next post) 2, there is so limited airflow to the radiator. I will look into the thermostat bypass setup. I hear taking out the Tstat is a PITA with the engine in the car, but that may be what i do.