We're running the iron LSX in a Z06 along with the APS Twin Turbo kit and the car is running pretty warm overall. Running a dewitts radiator, 160 thermo, and have tried both the stock water pump and an electric water pump and the temps are still well into the 220-230's

I'd like to get the temps down into the 190's. What options are there? Really isn't much room in there to move the intercoolers and we are running a dual fan setup and fan shroud(which helped). Also running two bottles of water wetter.

Do the iron LSX's just run warmer?

Note, it's also been pretty hot here. Mid 90's with high humidity.
The motor is also brand new with all forged internals(only has 200 miles) maybe as it breaks in it will cool down some?

Any help or insight is appreciated!!

Jason

 

I am just curious, but did you clean up the coolant passages before bolting it together?
https://ls1tech.com/forums/generation-iv-internal-engine/876792-your-lsx-overheating-heres-why-pics.html

 

They didn't see any of the coating flaking off inside the block when they changed pumps, and it's been running how since day one, so I don't think it would have had time to clog up yet.

There has to be a solution. Would the Evans water pump and removing the thermostat do the trick?

 

What temps do you have your fans set to turn on? Are you sure that you've gotten all air pockets out of the motor? Also, do you have your turbo's heat shielded? They're pretty close to the block, and with the amount of heat they generate, I could easily see them heating things up under there.

 

When I was running evans stuff I never noticed the car actually running cooler. There is an advantage as the evans T-stat flows 50% more coolant.

I dont think eliminating the t-stat all together would help either. If it did it would probably only be good for a couple degrees... definitly not 30.

Have you replaced the temp sensor for kicks, or verified the temperature with an external guage? Im not sure if the temperature guage on the z06 is digital or not, I dont remember, but I would atleast look into it and rule it out before you go spending any more $ on high dollar cooling parts.

what size motor is it?

EDIT: and as stated above, you need to edit the pcm to turn the fans on at 160 degrees to really take effect of the 160 tstat.

 

I have run the Evans inthe past. When you follow their guidlines it works. We ran the water pump faster as well as no stat. It would allow us a little extra timing in our tune up.

In your situation you are doing everything possible to make heat. The location of the intercoolers as well as the higher exhaust pressure will push that number up a bit.
Of course if you don't have the fans running at 160 as others have said it will not cool until you can move air through the raditor and cool the coolant.

The LSX block doen't run any hotter than standard block. It will probably retain the heat longer because of the extra mass of the block. The smaller the bore the thicker the cylinder wall will be. This will add to the mass.


Good luck!

Robin

 

I would also be very concerned about oil temperature. On my 408 I was running 280*, a 36 pass oil cooler brought me down to ~200*.

 

To touch on a couple things, the APS kit comes with heat shields and looking at it, I think it would be really hard to make them bigger. However, will look at this more once they get the car back in the air.

They've checked the coolant a few times and they have it all burped and working fine.

Motor is 427ci running ET LS7 6 bolt heads.

I haven't checked the oil temp, that would be a good thing to check though. Would also be a good indicator of what the engine is doing.

There are two identical builds being done and the 2nd car is expected to be running within the next week or so.(this ones mine, other is my business partners) am curious to see if they both experience the same high temps.

Also of note, the car runs 20degrees warmer with the AC on.

 

You really need to check the fan settings in the tune. If they're not set AT 160 degrees, BOTH fans, then you're sol in getting that thing cooled down. Also, are you running lean at cruise or with the AC on? What type of tune is it, OL or CL speed density, MAF? Sounds like you may have several factors leading to your heating issue.

 

Wanted to follow up on this post as we really have not cured the problem yet. There are two cars now running with this identical setup and both have the exact same heat issues.

We are currently running Dewitts Radiator + Dual Fan shroud that puts out 2760CFM's through it. One is running an electric Mezeier water pump and othe other the stock pump. The Electric seems to cool the engine down better then the stock pump by 10 degrees, but it's certainly not 30.

One thing, with the APS kit, it does away with the stock shroud before the radiator. The one that forces all air coming into the engine bay from the front of the car. Right now, the fan can pull air from the engine compartment as well, so it recirculates some of that air. We've made a make shift shroud on one that forced all air from the front, but that didn't seem to help, so it doesn't appear that too much air is recirculated.

On a warm 90+ degree day after driving for 10-15 minutes, if I let the car sit at idle for 10+ minutes the temperature will climb up into the 230's. This is ultimately the only time the engine runs hot. At idle with the car not moving. On the freeway or normal driving it never gets hotter then 205-210(minus 10 degrees for the electric water pump car) However, will also say when it's gotten into the 230's, I never hung around to see if it would go higher, so as of now, I don't know if it caps out.

Also, oil temps seem to be around the exact same as coolant temps. FWIW the cars now have 1200 miles on one and 700 miles on the other.

Heat shielding on them seems to be about as good as we can do. Another option is to ceramic coat the hot side of the turbo's in addition to the manifolds. this may help reduce heat and have the added benifit of allowing the turbos to spool quicker.

I know the LSX is a siamese bore block, do you guys think it's just going to run hot?

Thanks for any help you guys can give me. FWIW, the car if smoking fast. Put down 930rwhp at 14-15psi through an automatic. And at only 12psi I ran a 10.41@145 !

Here's a video. http://www.youtube.com/watch?v=31CwVowWfOE

Jason

 

And the fans are running full time as well and those temps are with the AC OFF. I'd love to have my car running 210 max with AC on.

 

Have you checked your oil temp yet? That will tell the story as to what's happening in the engine. Think oil cooler, made an 80* difference for me.

 

We've had no problems keeping our LSx cool and we've got everything working against us. Our coolant temps come up and stick in the 170s.

We have a very small radiator and the turbo exhaust housing is right next to the radiator so it sees alot of radiant heat. We're going to put a heat shield on the radiator tank here shortly.

 

C6 Z06's run hot. My Z06 with the A/C on and idling will creep up to 220 in the South Texas heat, even though I'm commanding max fan speed. Once I get up on the highway my coolant temp will drop. With a Meziere electric pump my car ran cooler at an idle, but way hotter on the highway.

I've seen blown/intercooled C6 Z06's regularly run 220-230 with a supercharger.

Your situation doesn't sound surprising to me at all.

 

Jason, give me a call, Id like to talk to you regarding the heat. I think I might have some ideas.

Louis

 

I agree.. After I cleaned all of the **** out of the coolant passages, and flushed my radiator, my car almost never goes above 190*. Normally, it runs in the upper 170's to mid 180's. This is with a stock waterpump, and a 80/20 coolant mix.

Being that our AVERAGE Las Vegas daily temps are in the 110+*'s, I think thats pretty damn good.

Could someone have accidently flip/flopped the head gaskets, and blocked the rear coolant passages?

 

Also, sounds REALLY stupid, but "Verify" with a piece of paper that both of your fans are pulling and not pushing..

Dont ask me how I know this..

 

I'd try wrapping the exhaust before spending the money to coat them. Also, check the temp settings for the fans and whether or not they're pulling or pushing. I've seen that before.