black temp paint worth it for the csf or nah? given the pnp nature, and dropping 5lbs, even if that's negated by a heavier overall radiator, may be worth doing for the reliability. if it's a straight swap from the old radiator, save for cutting & crimping the wires for the spal fan, i can def do that myself. anything else I need to know? evo 6 hose from STM, and otherwise straight bolt on?

i can do before afters on temps since harry's uses obd2 and picks those up

 

I wouldn't waste the time to paint it.

Yup all pnp just need the wiring and upper hose. Side note, the stock spring clamps for the upper hose are barely too small for the STM hose so order it with clamps.

 

So on the front side of the thermostat housing you have the temp probe which goes to your gauge on the dash. and the back side is the ecu temp probe

 

there was an option for like black temperature paint, but ok.

gotcha, nothing on the radiator then.

 

Bumping this back up as I had another frustrating weekend of racing. 2 week prior, 95 degree day car was pushing coolant to spillover to the point of spilling out the top and dumping onto the ground which caused me to keep locking up front right tire. Called it a day and went home, waited for car to cool off and check the torque of the headstuds. Sure enough all 10 were loose (have about 1500 miles on the new motor and didnt retorque them as in the past they have never moved after initial torque). Well, anyway pulled the head off and redid the HG after having head checked by machine shop and resurfaced.

Back out again yesterday and it was another super hot day 95 at least, cant imagine what temps were like on the tarmac. Well, sure enough car was pushing coolant again to teh spillover. Yes, I know the spillover is an expansion tank so a lil movement is to be expected. But generally my findings are such that when it does the HG is compromised. Im going to check the head studs again tonight after work now that car is cool but Im wondering if I dont have enough cooling for the new setup and it cant handle these super hot days. Autox sucks in that limited airflow so not sure how it would relate to track folks.

Regardless, something needs to be addressed here as car got way too hot. I could hear a girgling sound in the upper rad hose and when pulling into pits I saw as high as 120c coolant temps in evoscan which to me seems like its just about teh point of boiling over.

My cooling setup is minimal, CBRD rad with fan and stock radiator cap 80/20 distilled water to coolant.

I can try 100% water and spike in some water wetter. Perhaps a higher pressure cap would assist too or maybe I need to look into some additional fans. But before all of this I still question if mechanically the car is happy or if this is mostly a function of the extreme heat.

Any thoughts or additional data points would be appreciated!

 

is your coolant temp gauge moving?

i fill my expansion tank to 1" under the mark, and i use 50/50 coolant/water + 1 bottle of water wetter. it moves quite a bit when it's hot and autoxing outside, but never spilled over. obviously way different setup here. may need to reburp your radiator

 

Temp gauge is moving. I need to get a digital one to monitor coolant temps easier as I was using my laptop to log coolant temps with evoscan. Again, I saw as high as 120c in the pits and was spraying the rad with copious amounts of water to get it back down to around 95c to go out for another run. With enough time between runs Id see around 110c but that still seems high IMO.

Shouldnt be air in the system; I use a spillfree funnel crank the heat and defroster and wait for tstat to open a couple times. Typically once you have heat there are no air pockets in my experience.

The plan for now is to pick up a 1.3bar rad cap and change my coolant mix to 100% distilled water and a bottle of water wetter. Perhaps my rad cap was just too old and needed replacement.

Hopefully I didnt lift the head again but assuming the studs are tight tonight then that should be OK.

Im wondering if perhaps more fans would help? My CBRD rad only has a small fan. Hadnt thought much about it as I never had cooling issues in the past. And again it was extremely hot yesterday and autox may be a lil worse in the cooling department vs on track bc not as much airflow. Im just thinking out loud here and trying to get the conversation started so I can get this taken care of. What I do know is focusing on my car's health all day vs my driving sucks.

 

i see hotter coolant temps autoxing than i do road racing, primarily due to the car sitting and just radiating all that heat. the coolant gauge would be between middle and hot until fired it up and the fan started running again. that is still very hot though, and 100% water may help the symptom but 120c is really hot..

 

Yea 250F is very hot. Water and rad cap would be a good place to start.

Do you know if the head was actually warped the last time this happened? I fought this same exact issue for the first two seasons I had my car and it gets worse over time. The first time I only had the head decked because that warped but the block was still straight and flat. Still ended up pushing water. The second time I had the head and block decked to not skip any potential causes. Haven't had any coolant issues at all this year since doing that.

 

Yes, its extremely hot. I could hear girgling in the upper rad hose so it was just about boiling which I think happens right around that temp given the factory rad cap pressure.

So 2 weeks ago when I realized it was pushing that much coolant I called it a day. Car also got hot but didnt have laptop on me so no clue what the temps were for coolant. I had the head checked and my machinist said that it didn't warp however there were some dimples from the head lifting and banging around. All the head studs were lose to that at least made sense as to why it happened.

I didnt have the block decked as, well its still in the car but it was decked on this last motor build about 1500 miles ago. I was under impression the blocks rarely warp.

Ill check the studs again tonight to see if they have worked their way loose. If they did then Id guess she got hot and that warped things or the car is detonating. Guess Ill cross that bridge tonight.

But again all of this and what I experienced yesterday may just be a function of the heat and my cooling system isnt up to snuff for the temps and power its making.

 

Sounds like you need bigger fans. I used to have a thick 58mm PWR radiator and now have a Koyo, but saw coolant temps climb on both of them (according to my VDO gauge) when the car was just sitting -- especially in a red flag situation in the middle of a road course session (stopping with no cool down), or just creeping in heavy traffic. I installed the Balrok "fan man" huge Spal fan in front of my radiator on the passenger side in addition to the puller on the driver side and I turn it on manually with a switch when I need it. It makes a huge difference when the car isn't moving over just the puller. Flip the switch and watch the temp needle come down. When on track, I typically turn it off, but it stays on when my car is just idling or moving slowly. It brings resting coolant temps in the summer down from 200-205 to more like 185-190. I'm sure it would work wonders in an autocross situation, especially between runs.

 

I've seen as high as about 210 on a koyo and koyo rad cap with NO fans (not installed yet just doing a test drive) in a drive through at taco bell lol. But then as soon I started moving the car began to normalize.

 

Maybe I need to make more power. My unpopular OEM radiator and Evan's give me no problems, even during HPDE in 100* heat. :P

 

Thanks for the responses guys. Kaj- no you dont need more power, power ruins everything! But you already know that!

So here's where im at. I checked the head studs again last night and I was able to get maybe an 1/8th of a turn, so yeah they did move again but not as much after the initial retorque so could just be that another heat cycle especially like this last where she got so hot.

I think car mechanically is OK at this point and most of this fiasco was a function of the high heat and humidity. Looking at the logs I saw coolant temps as high as 110c during the run but the 120c was a spike after heat soaking in the pits.

In the meantime I have a 1.3 bar cap on the way along with some water wetter. This time I will try 100% distilled water with a bottle of water wetter. Even if I see a drop in 10 degrees F to me thats a step in the right direction but I think might be asking a lot just with fluid change. The cap wont lower heat but stop it from boiling over which should help temps from spiking as well as pushing to spillover.

I also just ordered that 13" SPAL fan so I will be rigging that up when I have a moment. Again, during runs Im not sure if that will help but in the pits it should most certainly assist. I guess time will tell. I have another event on Sunday but the weather is looking to only be mid 80s so fingers crossed Eva will be happier.

 

On top of adding the 13" pusher fan on the passenger side, make sure the stock fan is set to run 100% duty cycle after 195-200* in the cooling fan control tables. IIRC the factory settings don't have it go to 100% until like 210 or 215.