savewave

I'm talking to a guy about building an aluminum radiator for my '65 BB. He's telling me that it will have a lot more plumbing in it and should improve the BTU exchange by about 30 percent.

When I told him I also wanted to put a 160-degree thermostat in, he said that would hurt, rather than help. He recommends putting in a 195-degree thermostat.

He said the 195-degree thermostat is needed to slow down the flow of water at highway speeds so water will stay in the radiator longer, where it will get the maximum benefit of the increased cooling capacity of the new radiator.

That sounds logical. Are any of you running 195-degree thermostats? What has your experience been?

Thanks for any advice.

:cheers:

magicv8

The thermostat thing has been done again and again. It's like asking if you believe in God, and if so, which one, and what way to worship.

Some on this board have had luck with no thermostat.
Some drill a hole to let bubbles through.
Some use 160, 170, 180, and 195 thermostats.
Some have stock aluminum or brass rads.
Some have nonstock rads
Some use water, perm green antifreeze, or (GM) pink antifreeze.

My take is that I had my original tanks recored twice in a 14 year period, and the rad started leaking on the CA ride last summer. In that time, the A-C in my car always gave the cooling system fits. It has NEVER been up to the added load. The recores and replacements are right up there in cost with custom aluminum replacements, so I am going that way now. Over the winter, along with the rad change, I lowered my license plate, switched to 5 year permanent pink antifreeze, made a custom nose mask (to allow better air flow on the road), added more shroud seals, and left the 170 thermostat in the engine.

I'll let you know how it all works when the temps get to 100F. :lurk:

PS: You will need to recalibrate your fan clutch (if any), when you change thermostat temps. Here are the instructions: http://www.corvette.net/cac/fan_clutch
:skep:


[Modified by magicv8, 8:21 AM 5/8/2003]

Subfixer

Any and all thermostats will restrict the water flow enough to let the radiator cool. The problem comes when the thermostat is removed completely. Then there is too much flow and the water does not have enough time to be cooled. The only difference between the 160 and 195 thermostat is the temperature at which it opens.


[Modified by Subfixer, 7:50 AM 5/8/2003]

Kid_Again

...you need the appropraite amount of heat retained by the engine to function per design specs....others who are more knowledgeable than me will be be specific but at least one MAJOR reason to have the engine heat up quickly is prevent fuel mix condensation of the intake runners....so, you NEED a tstat

...according the opinions posted here that i have been able to verify, these cars came with a 180 tstat and that's what you should run....the 160's are designed for the old, old alcohol-based coollant systems...opinions are like noses, everyone has one, but you can trace back the documentation on these points....all those MEs couldn't have been wrong


..i have to ask why would you pay to have a custom-made radiator when you can get basically any variation from the major manufacturers...not a flame but you may want to reconsider your thoughts on that


good luck


[Modified by Kid_Again, 9:13 AM 5/8/2003]

66427-450

180. And if it still runs hot, you've got other problems. Less (like 160 or none), and it will take longer to get to operating temp ...... you really don't want it to run colder than 180 when fully heated up anyway (if we're talk'n a street car).

:seeya


[Modified by 66427-450, 2:11 PM 5/8/2003]

savewave

Thanks for the feedback. I should have done a search before posting this thread, but I've got issues right now with my computer at home and it was taking about 4-5 minutes to load each page. :(

Why have a radiator made, rather than buying one already made? The place I'm talking to was recommended by some folks I trust and they have quoted me a price that looks better than anything I've seen online or in catalogs.

Thanks again,

:cheers:

Mel Foye

I would look into another radiator guy. There is no difference in the amount of flow when open between a 160 and a 195 unless the size of the opening is different. Yes the longer water is in the radiator the cooler it will get. Catch is the longer the water is in the engine the hotter it will get. From inlet to outlet a proper radiator will drop the water only 6-10 degrees. You want to have the temp spread going into the radiator amd what comes out to be less extreme for better cooling. Because of this your WANT the water moving fast through the entire system. Slow real hot water allows steam pockets more easily than faster moving water. Faster water creats more turbulence to remove the boundry cooler water next to the insides of the tubes.
For years the drag folks have tried to run cool while NASCAR folks run at 200-220. I figure normal driving is closer to NASCAR than it is to a 1/4 mile full blast and then shut it off for 2 hours. I have moved both 406s in my 62 Vette and Surb to 180s and they run better and don't over heat. Good cooling to you. Mel

6T5RUSH

Savewave,

Based on my own experience and comments here by MagicV8, Kid_Again and others, I'm convinced to change out my 160 thermostat to a 180. We're not quite into the hot weather yet, but I've done some things to manage the heat issue (guage readings). First, I've got an old brass radiator...same radiator that was in the car when I bought it 22 years ago this July. Think I've got my monies worth on this one??? You betcha!! One, I know I'm a candidate for a replacement radiator. In the meanwhile, these are the things I've done over this past winter to help in the 90 + heat ahead, sitting in traffic. That's the only time I've seen my guage go to a calculated reading of 210 - 215.

1. I bought a temperature reading gun. That determined my guage was reading 5 degrees hotter than it really was...that was good!

2. Bought some of that bandaid type foam insulation (the kind you peel away and stick around doors/thresholds) from ACO hardware and sealed off the gap between the core support and the front cross member (yes I have the factory shroud).

3. I flushed out the radiator and engine of glycol anti-freeze and replaced it all with DEXCOOL. Jury's still out on this one.

4. I plan on installing an aftermarket air conditioning system...either Vintage Air or Old Air Products. Anticipating doing that, I swapped out my original 5-blade fan for the factory replacement air conditioning 7-blade fan.

The site posted by MagicV8 for adjusting the thermostatic fan clutch is an excellent one and one I didn't know you could do. Thanks MagicV8!!!

If all of the above still finds me climbing to 210 degrees on a 90 + degree day in traffic, that adjustment will be the last thing I do short of replacing the radiator with an aluminum one big enough to handle air conditioning.

Bring on summer!!!

Jim


[Modified by 6T5RUSH, 9:08 PM 5/8/2003]

SWCDuke

I have lost track of how many times I've tried to correct this one. DEXCOOL IS "GLYCOL" - ethylene glycol to be specific. Ethylene glycol is the basic component of all autmotive antifreezes (except for a couple that are propylene glycol based, which I absolutely do not recommend, not does GM).

The difference between Dexcool and conventional green antifreeze is Dexcool's superior carboxylate (organic) anti-corrosion package, which provides better protection for the cooling system components including aluminum, without precipitating out salts that will eventually clog up our expensive aluminum radiators.

The type of ethylene glycol based antifreeze you use will have ABSOLUTELY NO IMPACT on system temperatures.

The other thing to reiterate is the importance of the ignition advance map on engine operating temperatures, particularly at idle and low speed driving. To avoid overheating you should have total idle advance of 20-25 degrees for medium performance engines and 25-30 degrees for SHP engines or engines with high performance aftermarket cams that idle at 14" or less.

Attaining these advance specs requires a properly selected vacuum can driven by manifold vacuum at all times including idle, and this amount of idle advance will minimize EGT and heat rejection to the cooling system, which can be verified with an IR gun. With proper total idle advance the manifolds should only read approximately 500 degrees.

Duke


[Modified by SWCDuke, 7:39 PM 5/8/2003]

6T5RUSH

SWDuke,

Thanks for squaring me on my description of the "green stuff" vs. the "yellow stuff!

I've seen your comments on more than 1 thread regarding timing and its affect on temps. Checking my timing and making sure that vacuum can is correct (mine idles hot at just under 14") will also be on my to do list.

Regards,

Jim

SWCDuke

With 14" or less idle vacuum you should be running the NAPA/Echlin VC1810 vacuum can, which is the replacement for the SHP/FI can used '64-up. Specs are:

start @ 4", max of 16 crank degrees @ 8"

This will assure full vacuum advance at idle and combined with 10-12 degrees intial timing will get your idle timing into the 25-30 degree zone.

Duke