LS-3 NC Cooling Help
 

Hello,
Just finished a 06 build with a new LS-3 with a cam - has well over 500hp at the crank. Been driving it around on the street and the engine temps seem very high - 230 in stop/go traffic ( does drop some when moving - 225). Got the AC done last weekend and saw an additional bump in temp - 236 and barely came down when driving over 55mph.

It has two 10" Maradyne fans that spec at 950cfm at zero static. Radiator came from one of the kit vendors and setup for the V8 install. Separate 10ga wires to each fan ( and good ground points) and their own relays.

Has anyone delt with a NC V8 build and over come the cooling issue? Think I might need to build baffles to help force air thru the radiator? Getting ready to run the Ultimate Street car challenge in a few weeks so I don't have much time to address it.

I will be taking the car to C&R Radiators on Friday and have them look at it. Worse case I'll have them custom build one but after discussing with them on the phone today they said that setup should easily handle the little 500hp.


Inputs / Suggestions??
Thanks!!
Couple of pics of the setup.

Is your shrouding good? I have the FM fan setup on my LS3 in an NA. I have shrouding in place in front of the radiator to force all of the air coming into the nose to go through the radiator instead of around it.

Are the fans mounted on the correct side of the radiator? A puller fan mounted in front works against you ... just a sanity check, I'm not calling anybody stupid. :-)

Are both of your fans turning? For a while, I only hooked up one fan because I was worried my circuit wouldn't drive two. It didn't cool well, because the fan that was turning sucked all of it's supply air through the fan that wasn't, instead of through the radiator. Once they were both turning, the car has no issues whatsoever.

did you put a vacuum on the coolant system to remove any air pockets or bubbles from the system?

Getting air out of the engine compartment is a huge part of cooling. If running a unvented hood, try removing the hood and driving around a bit (just be prepared for endless conversation).

If the hoodless experiment shows a marked improvement then it's time to investigate the various venting options. Vents and sealing the radiator dropped my temps 30degs.

Also, it's important to seal the radiator so ALL the air goes through it and not around.

Good Luck!

Getting air in - ducting is super important, especially for a car that will see track time, keep that sealed!

Getting air out - As 5.0MX5 said, venting may be necessary

I feel like you shouldn't be overheating with that fan set up, at low speeds/load, though. As a good reference on cooling system routing, and how to keep air out of the system, I reference this: Pirate4x4.Com - The largest off roading and 4x4 website in the world.