ive been doing a bit of cruising in my t/a and at 45mph with 70degree weather its been cruising at ~200 F, i have a 3 core griffin radiator with dual 11" be cool fans and proform electric water pump, i dont have a thermostat but instead i bought the restrictor plate kit that comes with three plates and installed the middle one, never had a problem with the old setup but this one is running too hot at idle temps go down to 160-180, i am running straight water and a water wetter, intercooler and transmission cooler are oth in front of my radiator, both gauges read the same one is on the intake by thermostat and the other on the driver head.

I will swap out restrictor plates to the one with the smallest hole and see what happens, do yall think my water pump is a pos?

both blocks and heads have been hot tanked pressure tested, afrs are in the mid/low 13s at cruise and timing is at 34. At wot at no more than 7psi it goes to 210 almost instanly, i am pulling almost 2*/psi and running 93octane (and water meth but havent used it yet)

 

i like to be in 180 range at wot full boost

 

Ehh.

Id grab a T stat and use the proper coolant mixture. Coolant also raises the boiling temps, so keeps the water from boiling which raises temps. That would be where i started to be honest.

After that you can kinda weed out other possibilities. just my 2 cents

 

Im gonna swap out restrictor plates and if that doesnt do it i will get a 160 tstat. The water wetter and water mix increases the boiling point and is supposed to be more efficient than antifreeze.

 

I had the same problem for a long while. My big thick core Griffen rad is designed for circle track racing and that is usually done at higher speeds ~80 mph +. They are so thick they dont pass air all that well so you need alot of air flow to get it to work well. I got dual LS1 fans with built in shroud around my rad and need both of them on in the hot summer to keep my motor at 200 deg. Timing and air fuel doesnt seem to help. I been there, done that. it was fan flow that helped and now I can keep it under or just at 200-205 on most hot days on cruise.

Electric water pump may also be a slight problem, it just doesnt pass enough water through. I dont have a stat or a restrictor plate now. Straight water in my motor with some of the water wetter stuff. Water is more efficient than antifreeze it just rusts the inside of the block more so you need something in there to help prevent some corrossion.

Also keep in mind the turbo is heating your oil temps up, and the motor is mostly cooled by oil. Get an oil cooler and temp gauge to see what you are hitting for temps. Cooler may help some.

 

Bingo, running straight water only does the track officials a favor in case of a leak. Boiling point for water is 212-degrees, and remember that the coolant system is not necessarily a "closed" container, per se, so the water will evapoorate because the vapor will not have adequate chance to condense, thus lowering your coolant level at those temperatures. Run the correct mixture of antifreeze with a 160-degree thermostat....

 

The entire system is under pressure so the exact boiling point of water is not 212, its going to be higher.

 

As I said above, the system is not a closed contained system, it bleeds under pressure, and when water turns into a vapor and the molecules do not have a chance to condense because it isn't a closed contained system, then the equilibrium of the two processes will not continue at equal rates, thus the water will break down and not be able to dissipate heat properly, not to mention evaporate in time...

 

Wheres the water go? I never lost a drop. Try taking the rad cap off when its hot, it is definately under pressure. IF the system is losing water, then you have a problem somewhere.

 

You cant really tell that way. You can lose very small amounts of coolant/water without ever noticing or it making a difference. But its not a completely seal tight system.

Fact is, go back to the basics OP. T stat(160 i would say) and the proper coolant mixture, doesnt have to be 50/50, base it off engine operation and your environment. Work from there.

Oh and the system can be under pressure and still not be 100% sealed.

Hope you get it resolved op

 

I suppose you are right but doesnt mean its not completely sealed. If the gaskets do their job, it shouldnt be leaking anything

Like i said, in my situation with a thick rad on my car, my issue was solved with more fan flow thru the rad. I still run no stat or restrictor and its perfectly fine that way. Just takes alittle longer to heat up but the car heats up so fast as it is, I dont want or need a stat.

I dont know how much flow those fans are giving you, but it may be worth a look.

 

it is a closed system up to a certain pressure.

a radiator cap is rated at a certain pressure, i think our cars are 16 psi (1991 at least), which is gage pressure not absolute pressure so 16psig+14.7Patm = 30.7psia. The cap uses a spring to regulate the pressure inside the radiator and coolant passages (slight variances in different passages because of changing flow areas but thats negligible for such a low pressure application in with an incompressible substance, water/coolant/whatever its liquid in the coolant passages). The only way that coolant vapor/liquid can escape is when the cooling system pressure exceeds the radiator cap pressure (16psig or 30.7psia), or the volume of the coolant increases with high temperatures and some flows into the overflow tank, which is just excess coolant mass that can't fit into the control volume at operating temperature so you don't need it in your radiator anyways.

With that said, the coolant/water vapor which is mostly in the top of the radiator and radiator tanks is at whatever the pressure is for a saturated liquid/vapor mixture at a given temperature. Since we know our absolute pressure (~30.7 psia) we can calculate the temperature that the coolant has to reach to produce a pressure high enough to cause vapor to "rush out before it can condense again" and result in a mass loss of the system (coolant leaving the radiator to atmosphere)

The saturation temperature of water at 30.7 psia is ~251 degrees Fahrenheit, so until the coolant (just water) reaches 250 degrees F your not running the risk of loosing any coolant that would fit in the radiator at operating temperature.

You could lose some coolant from evaporation out of the overflow tank but that shouldn't matter because if your coolant system is in proper working order it will expel only the excess coolant once at operating temperature due to expansion (the hydraulic force will overcome the radiator cap), so you'll never have coolant you "need" to fill the system at temperature in the overflow tank....

 

yes! small leaks that run onto hot engine bay components will evaporate fast making them hard to find (ask me how i know!)

and i'm pretty sure water is more effective as a coolant that "antifreeze" or similar... I can look it up if anyone is really curious it's 4am and I have a numerical methods test at 8am I need to get back to studying!

 

Thats the only thing I can think of but on my car I have a sealed overflow tank with no vents so my system should be completely sealed except for the rad cap at 15-16psi or whatever.

Heat latency / specific heats... water has better properties compared to antifreeze, making water a better coolant. It has a higher capacity to absorb heat but the antifreeze substances are generally more dense than water so in a fixed volume cooling system, you have more mass of coolant available which gives it increased capacity to absorb heat. It also has less surface tension than water which is more desireable. I dont know where the tradeoff is tho, does the extra mass of antifreeze mixtures make up the difference of specific heat/heat latency that water has?

http://www.jcna.com/library/tech/tech0011.html
That article seems to say anti-freeze stuff or the 50/50 mixes are the best coolants, but water with water wetter additive is also high up on the charts.

I'm still going to use straight water and water wetter stuff like I have in the past.

 

The cap itself will dictate pressure, but regardless, I ran straight water all summer long with a functioning 16-lb radiator cap and the water boiled just after the 212-degree mark was reached. Once it went over 220-degrees the overflow tank began spewing. You have to understand that the calculations used to determine boiling points is always used WITH antifreeze involved, and it is never used with straight water alone. Water does a horrible job at heat transferring. Easiest way to test would be to bring the engine up to 220-degrees with straight water, or close to it, shut it down, then listen to hear if it is boiling. I guarantee that it will. If the original poster is "idling" at 160-180 using a water wetter, but is gradually increasing behind a load, then that would point to the radiator not being air cooled from the front as it was originally intended to be from the factory....

 

hmm thats weird you had some issues. I never had a 'boiling' problem and i've been over 220 deg before. It may have boiled off some water in the system but never spewed out the rad overflow or nothing. I checked it and only had a few drops of water in my container.

On one occassion I hit 220 and popped the waterneck hose off and with the great release of pressure, it all instantly turned to steam But water does a GREAT job of heat transfering.

Look up the video on youtube i think, about boiling water in a paper cup. Guy applies a torch to the side of the cup and although it chars the paper cup, it does not burn completely through. The water was boiling in the cup so it was taking heat away from the paper.

 

so because you had a certain experience with your car you think the basic laws of thermodynamics don't apply? If you were boiling straight water at just over 212 F you DID NOT have a pressurized system or one just barely over atmospheric pressure. I bet you had a bad gasket/cap or something somewhere and you just didn't know it. There are pressure caps on radiators for a reason, to raise the boiling point of the coolant allowing a common substance like water to be used to cool things at a greater temperature than their atmospheric pressure boiling temperature.

and no, it is you who has to understand that boiling points are NOT "calculated with antifreeze". The data I quoted is the from widely accepted thermodynamic property tables, it is for 100% water. And also water a much better medium for carry and transferring heat in a cooling system than glycol
if your radiator has boiling liquid in it when you shut your car off with your coolant temperature below the respective temperature for boiling related to the thermostat pressure rating, your cooling system is not sealed.

and these car are bottom breathers from the factory...

so much incorrect info in this thread

 

because of the sudden pressure drop, the boiling pressure dropped and it instantly vaporized. exactly my point.

water is one of THE best liquids to use in a cooling system.

OP, how much factory ducting did you leave in the car? The air could be getting trapped in a "spin cycle" like behind a truck cab around you radiator if your ducts aren't working correctly and that would amount to very little new, cool air flow, your fans could just be recycling hot air? Didn't you have that issue Orr?

 

My first problem was using stock TPI fans and 1 was wired backwards so i was just blowing hot engine air onto the rad while 1 sucked cold air thru the rad like it was suppose to. Then i rewired them correctly but due to my different rad size, i couldnt get the fans close enough to the rad to draw air through the rad. It was just cycling hot air from engine bay. THis is when I saw on my 99 LS1 car, they have a shroud around the fans.

So I got an extra set of LS1 fans with shroud, and hacked it up to fit my rad. Worked great. REALLY noticed the difference in suction thru the rad. You can feel it pulling air thru now. I think its the shroud that really helped here. It forced the fans to draw air thru the rad.

My intercooler sits a foot away from the rad. Only thing on the rad is a tranny cooler. I still have factory air dam. These cars are suppose to be bottom breathers so my intercooler doesnt have to pass flow for the system to work, but I thought more air thru the front nose of the car would help. Now i'm not sure it is, but i dont have flow data of whats goin on under the nose.

I even made a custom nose cover around the hood latch area to block air from rising to the top of the nose in front of the rad. I wanted to force air thru the rad, so I figured the blockage on top would do so. So far i havent seen any improvements but it makes the setup look cleaner.

The only thing that significantly helped my situation was installing the shrouded fans and on the hottest days, i keep both running at all times to keep it 200 deg or so in somewhat city driving. Highway it was 190 or so. On cooler days, I can keep 1 fan on and still be in the 180's range. Winter time, I could keep both fans OFF and still be happy around 180's-190's under just about any condition, even in boost. If I turned both fans on, i could get down in the 160's

 

I'm not really sure where you're going with the "not 100% sealed bit," (nothing is 100%, but as long as you're within the pressure rating of the rad cap and don't have any leaks you're about as close to sealed as matters (if our cars used a pressurized expansion tank like newer cars do it would take care of most of the rest)... not sure what that even has to do with the initial question.

That said, I do agree with trying some coolant, antifreeze is not quite as efficient as water, but the thing is, especially with a turbo setup you end up with hot spots in the heads, and with you getting as hot as you are I'd bet that you've got spots in the heads that are above the boiling temp of the water you're using, and once you get some steam you have a problem- steam doesn't transfer heat even close to as fast as water, it insulates the hot spots and you end up running even hotter. Raising the boiling temp will probably help the situation.

Thermostat- unless you live somewhere that is warm year round (by warm I mean warm, like I wouldn't consider it if it ever got much under 70*, ever), I don't see why running without a 'stat makes any sense. I do drill bleed holes in them (2 3/32-1/8" in a street car, 3-4 the same size in a "race" car), but generally you end up with a better running combination with a stat. It's not going to cause the car to get hotter, it will just let it run at a more consistent temp.

 

I used a Volvo fan with shroud from a V70... And its a monster! ..keeps my temp right where I want it... It draws a shitload of amps, so I "softstart" it with a thermistor, has been working good so far.

 

I agree with using a 160* to 180* thermostat and adding some antifreeze. You need to start removing variables and those 2 things are pretty easy to do. The rest of your system seems pretty stout.

For the cruise tune, is there a reason you are running rich and retarded timing? It might not be the cause of your overheating, but approximately 15:1afr & 50* timing is what the tune should be at cruise.

 

50*?
running lean and sparking the wrong cyl at 5* would cause problems.

 

I run 50* at cruise and the car responds favorably. I also don't have overheating problems and I have the stock radiator/single fan.

From Lars Grimsrud (Distributor Vacuum Advance Control units
Specs and facts for GM Distributors):

 

.... lmao, do your own testing in such a system, and let's see your conclusion.

..... lmao, do your own testing in such a system, and let's see your conslusion.

.... ahh yes, which is why many vehicles come with water in their cooling systems in warmer area's right off of the showroom floor, being that their so much more efficient, and that it does not void engine and/or radiator warranty when being utilized.

Keep dreaming.

 

Are you serious lmao? I'm amazed that people would even encourage using straight water in a street/strip vehicle. Water has no lubricant's, causes calcium deposits, leads to corrosion (and you can't have corrosion in the system without, you guessed it, AIR being prevalent lmao), which in turn will inevitably chew up your water pump. Yes, use straight water, it is very beneficial and rewarding to your engine....

 

Dont be cheap, just buy the damn anti freeze and dont end up with a mess of red water........

 

Any details on how to setup a softstart with a thermistor? I have one of the big lincoln fans sitting around which I haven't bothered using since their startup current is so insane...

 

LMFAO, i dont think being cheap is the issue here, look at what the engine bay looks like and then get back at me, im sure $30 worth of antifreeze wont break me...

Its cool that you guys know all that stuff about water and antifreeze and those formulas and such, def. some interesting info .

I did go ahead and add a 160* thermostat and went for a cruise, it seemed like the car ran a little more consisten in the 195* range at cruise, but with any sort of hard pulls it went past 210*. I did add about a bit of green antifreeze tho. I am now being told to replace the 160* with the 180* and that should help things, only time will tell.

anyone think an airdam would help under the radiator? right now it sits about 2 1/2 inches lower than stock since ive relocated it,

what about running too rich? could that cause heating problems? i started very conservative on the tune and slowly working my way to right, same with timing, i will use the map signal to advance timing at cruise with the msd 6al-2.

any other suggestions?

more info on the volvo fan would be nice, what kind of motor do you have? did u have heating problems before?

i have two 11" becool fans with shroud, supposed to flow 2780cfm, idk if thats good or not lol

 

I just put a thermistor on the + wire to the fan...Have been working good so far.

Its a big thermistor....I'll see if I can get a spec for it later if you want?

I have a 415cui with a procharger....... Did have some overheating problems while citydriving due to my convertor that was about 4500rpm stall speed

 

Yea, that would be helpful, never heard of using one for that...

 

One of theese, will have to check whats in the car to be 100% sure (I got both)

"AS 1R040" or "AS OR550"


My first idea was to use a timer relay that disconnect the thermistor after a few seconds, but that would take some more wiring so I tried without and have kept it that way but If the thermistor will burn due to too much currect I'll just change it..

 

hey gta324 i was just watching your youtube video of the test drive and noticed you have some sort of air dam thing under the front bumper do you have any pictures of this? ive been thinkin about doing something like that to see if it helps temps.

 

I think you mean the one I used to have for the procharger IC. I now have A FMIC setup and just stock air dam.....

Procharger IC extra air dam

 

i should probably put the stock airdam back on

 

yea that would make a stock car run hot been there...

 

My car was exactly like yours. Overheating BAD! Sometimes 230!

I built a new air dam last night.

Tonight, I drove it WITHOUT FANS and it stayed below 185 with a 5" x 34" air dam"!
My engine is filled with Hardblok!!!

Try the air dam! It works!

 

do you have any pics?

 

one on my car is home made out of hard plastic sheet just cut to size then bent into a 90 degree angle drill out the bolt holes bolt it up done...

 

I put a pic on my photobucket. Sorry for the quality. I had to use my phone.
http://i1120.photobucket.com/albums/...014_163050.jpg
Hope this link works.
Basically,take a piece of angle iron and make a notch in the center. Bend into a slight V shape (basically the same angle as the front bumper cover). Drill holes in it to mount the plastic mud flap piece, then fasten it to the bottom of the core support.

 

So do you just run it in series with the load?

 

yes