last year my 85 would run 185 in town and 212 with the A/C on. I have added 100 extra HP over the winter, so i'm thinking i need more cooling. I measured the origional radiator and it's 1" thick. i TOOK THIS TO MY LOCAL RADIATOR SHOP AND THE REPLACEMENT ONE IS 1-3/8 THICK for $150. Do you guys think this is worth the money ? What other options are out there ?

I did have about 1" of debrees( leaves) between the bottom of the rad and condensor which is now cleaned.

What do you guys feel the optimal operating temps are ? I have a 160 stat and was thinking of going to a 180 ?


[Modified by mike 1985, 2:35 PM 1/14/2004]

 

Both radiators have one row of cooling tubes. The 1 3/8ths is unlikely to provide any advantage, unless your radiator has some blockage. Depending on the origin of the new rad, and it's construction, your old rad may transfer heat better than the new.

*I* vote to change the thermostat to a 180. You are already running hotter than that with the 160. The 160 just prolongs the warm up from the stat opening point to the evential running temp. The temps you have been running are GREAT, in my opinion. The 185 temp is on the lower end of the most desirable range.

One inch of debris between the rad and cond is minimal, but it's good you got rid of it. *I* would make sure there is no blockage in the rad, change to the 180 stat, reverse flush the whole system, fill with a good fresh 50/50 water antifreeeze mix, and pour in a bottle of Water Wetter. Be sure you get ALL the air out of the closed cooling system. You can wait on the Water Wetter, of you want to see if you need it and/or to prove to yourself how effective it really is. I think you're in good shape. Good luck, and...

RACE ON!!!

 

thanks,

the replacement radiator is exactly the same as the otigional and appears to be in good shape. I'll go ahead with the new slightly bigger one and a 180 stat. I have just rebuilt the motor so all the coolant will be new and fresh. There was quite a bit of built up in the bottom of the block. I also went with the dart iron eagles, maybe the have better coolant passages than the stock heads, i don't know.

Thanks

Mike

 

That new radiator isn't really bigger, it just has slighly wider fins. That MAY be a good thing. Is the old rad the origional? What brand or country of origin is the new rad?

RACE ON!!!

 

not sure what brand. he showed me a sample, it looks just like the origional one, lots of small real tight fins.

 

The way the tubes and fins are bonded together can affect the transfer of heat between the two. The more heat that gets transfered from the tubes to the fins, the better the rad cools. Many foreign made rads have a bonding (glue) to attach the tubes and fins. As you can imagine, that isn't the best conductor of heat. In your marginal case, I would think you'd want the best you can afford. I can help you get a genuine Modine radiator, delivered, for comparable money, if you have any doubts or want help.

RACE ON!!!

 

i decided not to let him do this.

What other options do i have? Any one found a way to put a bigger 2-3 core rad in the car ?

 

I suggest you stay with the 160 deg stat and install a 160 deg aux fan switch. Then splice the wire from that switch into the grn/wht wire of the main fan relay. This will bring the fan on around your stat which will help to hold down coolant temps. Remember you gain 1% for each 10deg of temp drop.

What mods does the new engine have?

 

If you drive your vette the same, then you won't realize the heat from the additional 100 HP. The biggest effect I had on my 87's cooling system was to install a Stewart water pump when the OEM died. Your 160 stat is wide open and is NOT controlling the temp and having the fan come on at a lower temp won't do squat for the temp because the radiator cannot get rid of heat fast enough. With a higher coolant flow (Stewart pump), your cooling system has more capacity. My 87 with the OEM pump on 90 deg day and stopped would go to 220 F (195 stat and fan bypass switch on) Now it goes to 200 and much more quickly returns to 195 when I get underway.

 

I have researched C4 radiators, fairly thoroughly. I have found no OEM application that will reasonably replace the stocker. Anything more than the 1 row stocker is a specialty aftermarket (expensive) 2 row unit. The first thing *I* would do is put it together and see if you have a problem. Bear in mind, that a new engine is likely to run hot for the first hour or two, regardless of the cooling system. The specialty, two row rads generally run $400.00-$500.00. Look on the left side of this page for "Restotations", "Aluminum Radiators". DeWitts is a forum sponser. I understand their prices are reasonable, and their product, excellent.

The problem with the 160 stat and the 160 fan switch, is if it does what is intended, your engine will run too cool. If it doesn't work, your fan will never shut off. Low temps are good for 1/4 mile blasts, but it doesn't do much to boil the condensation and contaminants out of your oil. For everyday driving your engine will be more efficient and last longer at closer to design temperaturers. FIRST, I would see if you have a problem. Don't forget the Water Wetter. Good luck, and..

RACE ON!!!

 

the new combo is 355
9.3-1
dart iron eagles ( 180 cc)
224-235 @.050 495-510 112 LSA
weiand stealth intake
750 demon.

2500 stall

i have a new stock pump, but i put a flow cooler plate on the back of the pump ( as advertised in jegs)

3.07 gear.


I think i'll try what i have and look into the rads to the left


[Modified by mike 1985, 3:40 PM 1/15/2004]

 

With that cam and compression, I don't see any problems with a GOOD stock cooling system. Good luck, and...

RACE ON!!!

 

i'm going to try what i have and some water wetter.

I'm still leaning toward the 180 stat in hopes that it will actually let the water stay in the rad and cool, as opposed to just circulating through.

Mike

 

Wetter water works only when you dilute the system to a high ratio of water. It is the water that is providing the additional cooling, not the additive. If there was 8oz of magic that could lower temps, Prestone and the others would have put that into the mix of their product already. Diluting the system is going to reduce the inhibitor package and hurt the cooling components.

Thermostats were created for two reasons: (1)To raise engine temperature quickly (2) To prevent the engine form OVERCOOLING. They have nothing to do with high end or overheating. If your home air conditioner was not cooling the house down, would you get a new thermostat? Of course not. The thermostat is telling to cool, it just can't.

http://www.dewitts.com/pages/categor...s.asp?catID=19


[Modified by Tom DeWitt, 10:58 AM 1/17/2004]

 

You might also check some of the threads here. It seems like alot of vette owners believe in drilling small holes in the thermostat base. Haven't tried it on the vette-but it seemed to work on the suburban. :rolleyes:

 

The reason people drill holes in the base of their thermostats is to help purge the air from the "horizonally challanged" Corvette cooling system. Once the cooling system is air free, those holes will have no affect on cooling. Except they MAY, very slightly, prolong the warm up. I don't see how this "helped" a Suburban, with the rad cap at the highest point of the system.


Tom,

Do you disapprove of Water Wetter? Or do you simply feel it's effects are minimal.

I like your home AC thermostat analogy.

For the record, do YOU have a range of temps that are best for our C4s for efficiency and longevity? About, how hot is too hot? Driving down the interstate, how cool is too cool? If you have the time, can you expand on the advantages/disadvantages of "overcooling"? Thanks, and...

RACE ON!!!

 

I like mine to run at about 200-210 oil and 180 coolant, and it stays in that range with my 160 and programmed fans. Down the road when my engine is finished I may switch back to 180 because I plan to upgrade the WP and radiator.

From my experience, you have to do any two of the following to keep your temperatures good: better WP, bigger Radiator, lower tstat, programmed fans in the chip. If you changed cams or are done with mods, then just have the chip reprog. to make the fan come on earlier and keep the 160 and you shouldnt have problems.

I would not mess with the radiator unless youre going to upgrade to a BeCool/Griffin/Davis-type larger radiator. Youre probably best off just upgrading the WP if you feel the need to do something.

 

I am interested in this as I am having real problems keeping my new motor cool. It is OK while cruising but as soon as I get into slow traffic or hiilly roads, the temps go up and have trouble getting down again. Also as soon as I stop the motor and it gets heat soak, a lot of coolant spits into the overflow tank sometimes overflowing it.
The whole system is new so it should be working properly.
How can you test the sytem to see if it is holding pressure when you switch off?

 

Again, I think the reason people drill holes is because they hear stuff from other guys and it sticks with them. It's kind of like how a rumor grows.
Bob tells jack that Jerry drilled holes and he thinks it runs 10 degrees colder. Jack tells Tom to drill holes and it will run 20 degree cooler, and on it goes.

You have no idea how many myths I hear every day. Once a week someone with a cooling problem calls me for a new radiator and later I find out that a friend told them to run straight antifreeze and no water. Now I ask you, what car and what manual says this is a good idea?

Back to the home AC analogy. If the AC wasn't big enough and the unit was running continously, would you install a "bypass" wire around the thermostat? This bypass (holes) would make sure the unit running at full all ready would continue to run.


I would go with the later, effects are minimal. Hundreds of people that told me they tried it without diluting the system and nothing happened. Then those who rave about it are running almost 100% water. Redline has done an excellent job of marketing a product that we all want to believe is possible. Just add this stuff and all your (expensive) problems will go away. It's simply the high content of water that lowers the temps. Is the WW enough of an inhibitor to protect the system with 100% water, not under my warranty it isn't.

I've been accused on the forums of recommending a new radiator just to make a sale and I would never do that. Many times I have "unsold" a radiator after talking with the customer and finding the real problem. I think the thing to do with cooling problems is review the obvious stuff first. Make sure you have a 50/50 mix, the air path is not blocked, the instrumentation is working correctly and confirm these temps with an IR gun. All the seals are in place and the fans are working properly. If after all this has been done, then take a look at a new radiator. Don't waste your time with the tricks, there isn't one.


I think we worry too much about temperatures. For some reason 200 degrees scares many drivers. After all, C4's were designed by GM to run higher than any prevous model. I think anything cooler than 180 in any engine is going to produce excessive wear and I wouldn't worry about temps in a C4 unless I was over 220 on a 80 degree day. The stock radiator with the single row and plastic tanks is marginal, but it is enough when working at its peak. Add in some internal corrosion, some crap in front, a few HP mods, and then it's simply not enough any more. Another good question :thumbs:


[Modified by Tom DeWitt, 5:39 PM 1/17/2004]

 

Tom,
Thanks for addressing my questions. I was particularly interested in your observations on "normal" temps. A lot of people on here advocate 160* thermostats for everyday use. As you noted in your home AC analogy, it won't make the engine run cooler. Some users comment that the engine runs hotter than 160, so the cooler stat does no harm. I contend that it prolongs warm up, and contributes to wear and tear on the engine. The other contingent likes having their engine run that cool. Like you said that isn't enough heat for effecient operation and boil-off of condensation and contaminents.

I respect the fact that WW does not have a necessary additive package. One of the classes I race in bi-weekly, does not allow antifreeze. Therefore, I run straight water in my daily driver during the racing season. What do you recommend for water pump lube and corrosion protection? My cooling system is stock.

RACE ON!!!