RussMan

Mine is an '84 Z28. Has a 383 with 72cc chamber heads. T5 trans. I compete in timed road course events. Idles cool. Cruises cool. But more than 3,000 rpm and it heads for 250 degrees plus. Problem is my cam puts my power range in the 3 to 5,000 rpm range which is about perfect for race conditions. New water pump. New PermaCool 16 inch electric fan that flows approx. 3,000 cfm. New hoses. New AutoZone three flue "heatbuster" radiator. New thermostat. Have tried no thermostat, and three sizes of washer style thermostat replacements. Advanced and retarded timing all across the spectrum. Removed A/C and condenser. What is my problem?

R Defever

are you running headers? that could be one of the culprits causing high underhood temps.

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85 Z28 (Soon to be GMPP 350 HO)
Headman Hedders and matching y-pipe, Edelbrock Performer, Ram Air, Accell cap and rotor, Accell Supercoil, 160 stat, highflow Catco converter, absolutely no other smog equipment, B&M shift kit, Rapidfires, numerous carb mods, and flex-a-light fan.

"If you think education is expensive, try ignorance."-Ben Franklin

RussMan

Nope, stock manifolds.

Grim Reaper

If it does this on the open road too, then check out your air dam; it directs air to the radiator and is the most common reason if the car overheats while driving on the open road.

JAMES POLEDNA

I believe I may have the answer for you. I had the same prob with my Z; while cruising on the hwy the engine would run 230*, but when standing still only 180*. I purchased the entire noise peice used and was unfamiliar with whether or not I had all the peices, which I found out I did not. The missing peices are not obvious, they are located inside the nose and actually channel the air directly to the radiator. I discovered this one day while I was looking through my Helms service manual where they have a picture of the parts in the engine cooling section. I made a simple deflector last night and installed it underneath so the air that goes through the grill cannot escape directly under the car. I left room for air to still come up from the airdam directly beneath the radiator though. I drove the car today in 95* heat and it never got over 160* with the AC!

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bought a wrecked(head on,bad)'84 Z28 rebuilt it in'92 parked it in
'93 and ordered a '93 Z28. Got tired of the 4th gen in '99 and sold it and begin swapping in '85 TPI converted to speed density. engine is all stock except for comp cam. body has '86 IROC nose peice,ground fx and IROC wheels/goodyear 245/50's. IMO this car looks and feels more "racey" than my '93 did. and I love driving it. BTW fuel injection is great I'll never go back to carbs.

RussMan

Appreciate the help...But, car doesn't overheat at any speed, as long as I'm under 3 grand. Bought an '86 Trans Am parts car for the 16" wheels and disc brake rear end. Swapped front air dam as well since the T/A piece was considerably wider and, well, bigger. Checked under the nose for air openings. Just one. directly in front of the radiator, about 7 inches wide across the length of the radiator. BTW, what wiring harness did you use for you FI conversion? ALso have a wrecked '93 Z28 I'm in the process of swapping the LT1 into my '84 MonteCarlo SS. Since I have the whole car ('93 Z) I figured I could get by without spending the $600 on a stand alone wiring harness. Anybody got more ideas on my overheating prob?

JAMES POLEDNA

Fuel injection specialties in San Antonio took the '85 TPI harness and converted to '91 spec. After I got the factory service manual I figured out that I should have done the work myself, its not that difficult. It cost $600 but they did swap computers and sent me a couple of sensors. They were also very helpful with questions.

MikeInAZ

Recheck your air dam. What is an air dam to one person may not be to another. There are 3 pieces to an air dam on an 86 T/A, not sure on a camaro.

1. In the nose, some have it some don't.
2. The wide strip that runs the width of the car.
3. The piece that diverts air into the bottom of the radiator and it bolts to the bottom of the radiator. This is the most important piece and really considered the air dam. The other piece is really a spoiler.

If you continue to have troubles put out a call for Mike Metzler, Desert86Roc. He knows the Camaro's and has done some cooling mods.

<A HREF="http://members.aol.com/mmmm999/3rd-degree/index.html"><FONT SIZE="1" FACE="MS Sans Serif"><IMG SRC="http://www.tribal-treasures.com/cars/post/arc/3rd-logo.jpg" WIDTH="100" HEIGHT="80" ALIGN="BOTTOM" BORDER="0"></FONT></A>

monte-ss

About your soon to be conversion, I did mine with a 89 IROC used the old harness off the camaro, only had to change the wiring to the dash and in the column (which most pluged right in) I have some cleaning up to do in the engine compartment on the pass side. Only other "mod" I had to do was the block that goes into the body on the pass side I had to modify a little bit and reseal it up nothing major at all. good luck making another monte what it should have been!!

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'87 Monte Carlo SS,with '89 IROC 350,700 trans, blew up 3.73 posi stuck with crappy 2.73's neeed gears! hooker headers, flow's 2 1/2" exhaust true dualls

RussMan

MikeInAZ

Best I can tell from your description, air dam part i swapped from the '86 T/A is your part 3.

monte-ss

I'd gladly accept any advice/instructions you might have to aid my swap. Feel free to e-mail me. Thanx.


Still don't have my overheating prob. fixed. Anyone? Anyone?

Vader

Russ,

There are other factors which can contribute to poor heat rejection:

* Paint on the radiator cores can lower its efficiency dramatically. HVAC technicians routinely find external condenser fouling and dirt to be the only difference between a working system and a failed one;

* Restricted exhaust can cause excessive loading of the cooling system. At least one-third of the engine-produced heat should be dumped out the exhaust system. The liquid side is not sized for handling that many BTUs';

* Lean mixture will result in higher combustion temperatures and more heat in the cylinder heads and walls;

* Retarded ignition and/or valve timing will result in higher combustion temperatures, lower power, and the necessity for more fuel to accomplish the same power output. More fuel burned means more heat generated;

* A failed or removed EGR will cause higher combustion temperatures (see above);

* Coolant mixtures containing more than 50% ethylene glycol will reduce the heat transfer capacity of the coolant. The heavier molecules of the antifreeze just don't hold and move heat energy nearly as well as water;

* Propylene glycol antifreeze compounds are very poor carriers of heat. These "environmentally safe" antifreeze compounds will probably cause more engine failures and resultant environmental damage than they could ever prevent by disposal problems;

* Higher friction from loading can cause an overload of the cooling system. Additional heat from an automatic transmission under heavy use can overwhelm the engine cooling system. A separate cooler would remove that heat from the system. (I know you have a manual trans, but for the auto guys...);

* The same holds true for the engine oil. The oil itself is expected to transfer heat away from engine parts and needs to reject that heat somewhere. A separate oil cooler or finned pan can help dump some of that heat away from the cooling system;

* An engine with dirt and oily deposits caked all over the outside has a very effective "insulation blanket" wrapped around it. Clean off the engine to allow some of the heat to radiate to the surrounding air. Don't overlook the oil pan and transmission bell housing, since some of the engine heat is leached away from the block by everything that is bolted to it.

* Lower friction means less heat generated. Synthetic engine oil can help with this, and will tolerate the higher heat without breakdown. Once your oil starts to break down, the friction increases, so more heat is generated, and so on. It becomes a never-ending spiral downward until the engine seizes;

Good luck. If you didn't have a couple weeks of 100°+ temperatures, you probably wouldn't be posting this thread. But these extremes bring all the little problems to the forefront.

Later,
Vader


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"Make Me Bad"

[This message has been edited by Vader (edited July 23, 2000).]

RussMan

Vader,

Thanx for the input. Motor was previously in my '75 Laguna S3 which I was drag racing. When the 305 laid down, decided to do the swap. Motor didn't run hot in the Laguna, but only got 9 second abuse at a time. Timed runs in what I'm doing now can exceed 5 minutes. Obviously, I'm not comparing apples. Radiator is new with factory paint. Are you suggesting I should try to strip it? Was running headers on the 383 in the 'Guna. Now running factory exhaust manifolds in the Z. Is that too much restriction? Rest of exhaust is: no cat, no muffler, exits rear.

Been considering the oil cooler option, but hate to invest the $ on a hope and prayer. Done enough of that. Great advice on the synthetic fluids. Have noticed a direct correlation between increasing temp and decreasing oil pressure. Hast thou further advice? Thanx again.

Vader

Russ,

If you have the factory paint ONLY on the radiator fin-tube, I wouldn't advise stripping it. If the radiator was repaired and had copious amounts of touch-up paint applied, I'd consider it.

If you're making gobs of power and running straight exhausts, the stock manifolds shouldn't be a problem. The restrictions that normally cause heating are the cat and muffler/resonator. It sounds like you've cured that problem. Exhaust gas velocity should be more than adequate.

I was going to point out that a factory radiator may not be adequate, but you've already slipped in a three-core. Solved that one, too.

The next question is flow at RPM. I've had water pumps that have moved enough coolant at moderate loads to keep things cool enough, but wouldn't cut it under load. I've seen the impellers actually erode from cavitaion friction and from metal ion leaching until there were almost no vanes left to move coolant. This was on an older engine with some mileage, but if you installed a remanufactured pump, it still might be worth looking into.

Be careful of remanufactured pumps. I've pulled the back cover on some freshly rebuilt pumps and found almost no vanes there as well. I've been burned by this once so I am in the habit of checking before installing a replacement.

You might also want to make sure your lower hose is not collapsing from suction (not YOUR lower hose - the one on the car. Mine rarely collapses from suction...) If the lower radiator hose doesn't have the reinforcement spring inside, you may have a flow problem at RPMs. You can have the same problem with the corrugated hoses caused by the rubber delaminating inside the hose, thereby blocking flow, but a new hose shouldn't experience that.

If you aren't using the heater core, you need to make sure that the coolant connections still exist. The water pump needs to be able to extract coolant from the head and circulate it through the radiator

Obviously, a thermostat problem would cause the same symptoms, but you've already addressed that one too.

If anything else comes to mind (other than moving above the Arctic Circle) I'll post it.

Later,
Vader

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"Some Body...Someone"

RussMan

Vader,

Overheating has persisted with two separate water pumps...an old one I put on when I assembled the motor, and a new, not reman, one i got from Advance. My lower hose is fresh and includes the sring necessary for suction based collapsing resistance (as does the one on the car.) More good advice on the heater hose. Not using the core and probably have a flow problem in my bypass hose.(If that's what you were getting at.)

Bad thing is that now it's Sunday PM and I'll probably have to wait til next weekend to accomplish these recommendations. If you come up with additional ideas, consider me a sponge. Incidentally, I've been fighting this problem since about May, so ambient temps as low as 75 or 80 degrees have seemed to result in the same 250+ degree enginee temps.

Thanks again for your help,

RUSS

RB83L69

Try a good water pump, like at least an Edelbrock or preferably a Stewart. They flow far more coolant at high RPMs than a stock one.

Check your distributor for good centrifugal advance, if it doesn't work right then your timing will be too late at high RPM which leads to inefficient operation in the form of combustion continuing to occur after the piston is so far down in the bore that the new heat can't be turned into mechanical energy. Same general reason for excessive temps due to lean condition.

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"So many Mustangs, so little time..."

RussMan

Thanks for the input. Will probably try both. Got to get this sucker cool for 'Stang spankin'.

FJK

RussMan:
Here's a thought to consider. I basically have Ford experience so don't hold this against me. On sb fords, early water pumps that are driven by v-belts operate in one direction. Pumps that use a serpentine belt operate in the oposite direction. Is this the case with GM's as well? I raise this point as you said engine was ok in 75 vehicle & not ok in your 84.
Regards, FJK