327 radiator

[camaromikey]

I have a 69 camaro with 327 that is 60 over. I have a 23 inch 3 core BB radiator in it now and it doesn't go over 160 with a 180 themostate. i know this is a hard one to guess at but how big of a difference would it make in switching to a 20 3/4 inch 3 core SB radiator. the 23 inch has a leak and 20 inch i can get for cheapier.

[rich69rs]

My 69 327 (RS Coupe, Powerglide, no A/C) is 30 over and the stock radiator/cooling system (4 blade fan; 21" wide; 2 core radiator) works just fine.  The console temp gage (based on "calibration" of the gage from IR reading on the thermostat housing) indicates that I run between 185 and 210 F. 

Assuming no major engine mods, and following the recommendations on timing given by JohnZ in this link (TIMING AND VACUUM ADVANCE 101) and you should be ok.  http://www.camaros.org/forum/index.php?topic=64.0

Matter of fact, your current setup with an engine temp no higher than 160F is probably causing you some loss of thermal efficiency (heat loss to the cooling system instead of creating power).  180-210F is where it is designed to run.

[jdv69z]

Are you sure your 180 degree thermostat isn't opening at 160 degrees? Defective?

Jimmy V.

[tom]

Or possibly not closing completely?

Tom

[camaromikey]

i've been running a 60/40 mix on coolant and with a bottle of purple ice. I was runing 180 till i poured the purple ice in.

[hotrod68]

From my experience, any 3-core radiator will cool a 327. In fact, a 3-core is a little bit of overkill. No wonder your 180-degree thermostat runs at 160! Once the thermostat opens and the coolant temp stabilizes, the water is just too cool to allow the thermostat to operate properly if the ambient temperature is not very high. The smaller radiator will probably be better for your 327 because of its decreased capacity. If it were me, I'd also put in a 190-degree thermostat to help the engine burn off the crankcase condensation since the weather has turned cool. That's my 2 cents. Good luck!


 

[camaromikey]

you guys are great. Im going to switch to full vacuum and to a smaller radiator. thank you all. Your a big help

[JohnZ]

you guys are great. Im going to switch to full vacuum and to a smaller radiator. thank you all. Your a big help

No need to change the radiator! What you need is a new thermostat - get a Robertshaw #330-180 or the same thing by Mr. Gasket, #4364. Thermostats aren't "on-off" - they modulate the coolant flow based on its temperature, to maintain it at least to their rating. The Robertshaw/Mr. Gasket thermostats are calibrated more accurately than the generic replacements. Doesn't matter what radiator you have - if the thermostat is doing its job, it'll run at 180*.

[camaromikey]

im running a Mr gasket 180 right now.

[JohnZ]

Have you checked the temp gauge reading against an I.R. gun shot of the upper radiator hose just above the thermostat housing at the same time so you know what the gauge is really telling you?

[hotrod68]

I must very respectfully disagree with John Z. From my experience, if the radiator is too big and the water is cooled too much going through it (i.e. cold ambient temperature, too big a capacity), it will "confuse" the thermostat and the thermostat won't operate within its design limits. I exclusively use the RobertShaw/Mr. Gasket thermostats because they're the best, and I've seen this happen many, many times, especially with the car at speed with a lot of air going through the radiator. A slide rule and a computer may say one thing, but the real world is another. The cooling systems in these old cars are like photons in the subatomic world--on the surface they are what they are--but they don't always behave as the physicists predict. If you fool around with hotrods long enough you learn this very quickly. The 327 low-performance cars came from the factory with smaller radiators for a reason, and it wasn't just because of the corporate bean counters. You can over-science anything, and I believe his radiator is just too big, for what my non-college-degree opinion is worth....chuckle. Good luck, Mikey!

   

[tom]

What are you basing the temp reading on? Factory instruments are not the most accurate. Like John said, check the temp with an infrared to find out what temp you are really running.  Could easily read 160 when really running at 180 or higher. Once you know where it should run, don't sweat the numbers, as long as it continues to run the same.

Tom

[camaromikey]

Unforunatly right now, I can't check it because i pulled the radiator. I went with 20 incher because my 23 incher was leaking from the side tank. Im still going to get it fixed. I forgot it was a 4 core instead of a 3 core. I will use a IR gun as soon as i get it back togther because i was warned about since i bored it 60 over that it would run hot. It was orignnal running 200 to 220 with a 190 themostate and the 23 inch 4 core radiator but that was according to the guage. Im just hoping that the 180 themostate and 20 inch 3 core will make it happy.

[pdq67]

4-core wide rad!

WOW, about as good as it get's!

It will cool a 496!

I installed a '66 Buick Special 4-core in my car back when I installed my hopped up .060" overbore 11.5 to 1 CR'd 409 "W" engine b/c I knew darn well my OEM 350SS rad wasn't big enough.

Had to hang it b/c it didn't have stock side mounts.  It's under my work bench b/c I have a cheap Summit/Northern Aluminum Rad wide 2-core hung in it's place to cool my 496.

pdq67