[BMFH]

Hello All

What type of car are you working on??

Look under your car, see if there is a spoiler/air dam directly under the RADIATOR.

If your car is what they call a BOTTOM BREATHER, the Spoiler/Air Dam is VERY, VERY, IMPORTANT. Its job is to cause a high pressure area that allows the air to be directed up and thru the radiator, the low pressure area behind the air dam causes the air from the radiator to return back under the car.

I worked in a Pontiac Dealership in the 80's, one of the Mechanics was pulling his hair out trying to get a 84 Firebird to cool, tried everything, replaced everything, finally re-installed the MISSING Air Dam, EVERYTHING WAS COOL after that.

Hope this helps,

Good Luck,

Dusty

[General Z]

It is a 67 Firebird convertible. I have all of the air dams and AC baffles in place.

[indymanjoe]

General,did you go to bakers yesterday?

[kyle_blake]

Is 205 a bad temp to run with these Pontiac's? I heard 180 is the best all around temp, I thought the stock temp gauge had these cars at 210F?

[67cruiser]

Call Precision automotive, Talk to LARRY, MAN IS A GENIOUS!! he will find a solution.

[David Jones]

Integrated shroud?
That means it only pulls air directly in front of the blades versus pulling air across the whole surface area of the radiator?

[bluebandit]

Have you tried putting the thermostat in a pot of water and putting it on the stove with a thermometer and watching it as it gets hot. It might not be opening when it should.

[steve25]

Like I posted before retarded cam issue!
I would go in and advance the cam 4 degrees. new timing chains give up a degree or 2 at high revs anyway and at lower revs the additional cylinder pressure will get the EXH out of the motor much better, as I would bet my bottom dollar that this is your problem at this point due to what you said in your posting about not having a temp issue with the other cam!
Also so too many fan blades can make for a hot running motor when traveling down the road at more than 40 mph, as they block air flow from getting thru the radiator at a time when the motor does not even need a fan,

[craigs69]

Originally Posted by mchell

4 core aluminum radiator ?

Piddled around with mine for years....on a whim I replaced my high buck aluminum radiator and put in a 2 row 1.25 inch tube Griffin...wha la .....no more 200++ temps....two different engines, same cool results....in fact, it cools so well,I was able to get rid of all my "heavy duty" cooling garbage (fans, clutch etc....).....running standard duty fan,clutch and shroud...damn thing cools well!

I had the same result. Got a 2 row aluminum with 1.25" tubes also. No more temps over 190.

When I bought my car, it consistently ran 200+ temps that would creep up to 210-215 on hot days. I tried adjusting the clearance between the stamped water pump impeller and divider plate which did nothing. It wasn't until I replaced the missing air dam, core support seals and added a 2 row aluminum radiator with 1.25 tubes that my heat issues went away. I am still running the water pump with a stamped impeller, and I just removed my seven blade clutch fan over the weekend and replaced it with a smaller 6 blade flex fan. Still no water temps over 190 degrees.

[General Z]

indymanjoe: No, I almost never go to Baker's. It is one of those things, where it is so close, I take it for granted and never go.

David Jones: The fan is HUGE. It covers the entire radiator and then some. It is actually about an inch taller than the radiator, so I made a cover for the bottom of the fan, so that the fan isn't pulling air from anywhere but through the radiator.

bluebandit: I think I tried that. I think I'm also going to try a different thermostat just to see. I have one too that I ripped the guts out of, so it is just a disc for a slight restriction.

craigs69: You're saying that the 2 row, is better than the 4 row I have now?

Thanks guys.

[craigs69]

Honestly, I don't know if the 2 row is any better than the 4 row. I replaced my old original 3 core Harrison with the 2 row aluminum radiator, added the front air dam and installed the core support seals all at the same time when I redid the car in 2012. I am not really sure if any one of those items solved the heat problem or if it was all of them together.

[getmygoat]

I agree you may want to take a closer look at the radiator...As radiators age, they lose flow capacity and cooling capacity.

I had two different GTOs with overheating problems... same scenario as you - screw around with a bunch of BS... nothing made any major difference. In one GTO, I replaced radiator with a Rodney red aluminum. Problem gone... could cruise on a 90 degree day with A/C on - no problem.

On the second, I recored radiator with a high performance core (denser fins per inch). Again, dramatic improvement - end of cooling problems.

p.s. - A 2 row aluminum radiator has more cooling capacity than a four row brass radiator as aluminum dissipates heat that much better.

[General Z]

The radiator is probably 2-3 years old and probably has under 1000 miles on it. It is the Champion 4 core, big block. Maybe I need something better than Champion, like Griffin or Rodney red.

[General Z]

Except, I have a thermocap on my radiator and the same car, same engine, same fan, same radiator, the fan used to keep the radiator at 160 all day, regardless of how how the coolant temp sensor on the engine got. Not the case now.

[PontGuy]

Getting confused. Is this right?

With no major changes to the cooling system...

• The engine ran cool with the low compression heads before the rebuild.
• The engine ran hot after rebuild with the XE cam and heads swapped to 96's, but with low compression on one cylinder due to a ring problem.
• The engine runs very hot after installing the 2802 and fixing the rings on the low compression cylinder.
• You lost a bunch of bottom end torque with the 2802 compared to the XE.

Seems like something is just wrong somewhere. Suggest another compression test to make sure that all of the cylinders are OK now. The numbers should also help confirm that the cam is installed correctly and you are building compression.

[General Z]

That is all pretty much correct. Thanks

[Cliff R]

You didn't loose any bottom end power with the cam swap. I've built 10 to 1 compression 400 engines with unported heads that outran 9.5 to 1 compression 455's with the XE262 cam in them!

The tiny XE262 cam is so small that it simply has the big 455 making ALL of it's power right off idle, so they "feel" snappy because of this fact, but in reality dont make very good mid-range and top end power in those engines.

Even using the larger 60919 (RAIV clone) cam in a 455 with at least 9.5 to 1 compression will make enough low end grunt to pull the end out of a ditch! With some high ratio rocker arms and Rhoad's lifters on that cam you get a power curve flat as Kansas, with peak power up near 5500-5600rpm's.

The 2802 woln't quite do all that, but it will make over 500ft lbs torque across most of the loaded rpm range in a 455 engine with mid 9 to 1 compression. If you are way down on power, running hot, overheating, pinging, and not overly impressed with the cam swap, there is a fundamental problem with the basic set-up, most likely cam timing if I had to take a guess at it......Cliff

[General Z]

Thanks Cliff.

[Nickv]

install a Lincoln Mark VIII electric fan. I did on my 67 and took care of all cooling issues period.

[General Z]

That is what I have Nickv