[Speargun]

1800 miles on the new build in the '67 Bird and I still can't get it to run cool.

During the day (75*-80*) the car will be pushing 210* - 215* (sometimes higher) after 15 miles at 55mph (<2500rpm) and a stop light or three.
At night (60*-70*) it will run anywhere from 190* to 205*.
Idling it usually stays around 190*.

So far I've tried 2 different radiators; a 4 row Champion & a 2 row, 3 pass, radiator.
I have 2 electric fans (Spal 11" & 12") with a shroud. (2300 cfm +/-)
High flow 180* thermostat.
FlowKooler pump that the divider plate has been clearanced on.
Total system capacity is about 3 gallons +/-. (Bottom filled 469cid with E-Heads @ 10.25:1)
2 quarts antifreeze
1 bottle "Water Wetter" & the rest distilled water.

I have an inline coolant filter and can see that the thermostat is opening when it should & the flow looks good.
There is an AC condenser a couple of inches in front of the radiator, but I can feel the fans pulling air through it pretty good. (AC is not hooked up yet.)

I did the divider plate today & was hoping that would cure my problem, but it didn't.

The only other thing I can think of right now is to step up to the better Spal fans which should give me around 3200 cfm, but will cost $370!!!

Anyone have any suggestions?

[ponyakr]

A Cold Case 2-row, with 1.25" wide tubes is supposed to cool better than a 4-row.

http://www.firebirdcentral.com/1967_..._p/rad-403.htm

I've read that a big Pontiac needs close to 5000 cfm air flow to cool properly.

The only auto elec factory fan I've read of that will come close to that is from a Lincoln Mark VIII.

http://www.hotrod.com/articles/ccrp-...radiator-fans/

Some dual truck fans will even exceed 5000.

So, if you wanna stick with elec fan, you may need to upgrade.

Many seem to have had good results with clutch fans, plus an HD clutch, such as the Severe Duty Hayden 2797.

https://www.amazon.com/Hayden-Automo.../dp/B000C3F3D4

[tom s]

Have you put a lazer temp gun on the inlet and outlets of the radiator?It will tell you how much temp drop your radiator is giving you.How is the timing.A lot of pontiac over heating comes from retarded timing.Just hints.Tom

[Speargun]

I have a 2 speed " Mark VIII" fan, but it won't fit without hitting my water pump pulley.

I currently have the timing set just below where I get spark knock.

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[Lee]

Originally Posted by Speargun

I currently have the timing set just below where I get spark knock.

You get spark knock with Edelbrock heads and only 10.25:1 compression? You must have over 40 degrees total - BACK IT OFF!

Also buy/borrow a wideband and check your AFR.

Personally, I'd put it on a chassis dyno with a wide band hooked up, and see how far off the tune is. Just getting the timing and jetting corrected could cure your cooling issues.

A 3000 cfm Black Magic shrouded fan and a BeCool 2-row were enough to keep my old iron head 469" (see signature) running 180 most of the time, in Houston heat.

[Speargun]

Originally Posted by Lee

You get spark knock with Edelbrock heads and only 10.25:1 compression? You must have over 40 degrees total - BACK IT OFF!

Also buy/borrow a wideband and check your AFR.

Personally, I'd put it on a chassis dyno with a wide band hooked up, and see how far off the tune is. Just getting the timing and jetting corrected could cure your cooling issues.

A 3000 cfm Black Magic shrouded fan and a BeCool 2-row were enough to keep my old iron head 469" (see signature) running 180 most of the time, in Houston heat.

I have a wideband on it & can set my AFR at whatever I want. Right now it's set at 14.2 or 14.5 at cruise, 13.8 @ mid throttle, & 12.8 @ W.O.T. (iirc) I would have to look at what is programmed to be sure.

[Lee]

Originally Posted by Speargun

I have a wideband on it & can set my AFR at whatever I want. Right now it's set at 14.2 or 14.5 at cruise, 13.8 @ mid throttle, & 12.8 @ W.O.T. (iirc) I would have to look at what is programmed to be sure.

Good! Only concern there is the accuracy of the unit. I recently saw an AEM that was WAY off.

Now pull the timing down, and see how it runs.

[george kujanski]

Attached is a graph I copied a while ago for a radiator from a manufacturer's site, (I don't remember who). It can be clearly seen that the heat transfer rate in BTU's/min INCREASES as the airflow and/or coolant flow rate increases.

Not only that, if slower is better, reducing coolant flow rate to zero should be the best.........unless there is some happy spot where it's the best. Problem here would be to find that happy spot and use a constant speed pump which the automotive engineers did not design in.......

Can't argue with Physics.

George

[1967Tempest]

Originally Posted by Speargun

I have a 2 speed " Mark VIII" fan, but it won't fit without hitting my water pump pulley.

I currently have the timing set just below where I get spark knock.

Sent from my SM-G930V using Tapatalk

I have this fan in back of a Griffin 2 row 1.25" cooling finned radiator. The new 468 runs 190*-195* all day in northern VA traffic. (Driving it to NC from NJ) The lanes were very freshly paved so the road was BLACK!!! Imagine my surprise that an early March day got over 90*!!

I use the Hollister Road relay assembly with the high coming on at 200*. The low is negatively grounded through a Derale fan controller that is adjustable. I have a 180* t-stat that is fully opened around 190*.

I did have to make special lower brackets for this rad and it is canted. Meaning the top is more forward that the bottom. I had to cut out and or bend the top of the rad support to get this rad to fit. Im running around 50/50 coolant and water.

So if you DO change to this set-up it WILL take some messaging.

The other things that might get overlooked.

Alternator voltage when both fans are running at idle. I have killed about 6 of the Summit 1-wire alternators, not knowing that a 100A alternator doesnt put out 100A at idle. I have a new billet 200A alt that puts out 140A at idle. Fans, not pulling hard enough.

The WP pulley is way too big.

Any brakes sticking?

Do the fans cover the entire radiator?

Mismatch gasket in the crossover? That can impede flow as well.

Size of the t-stat, high flow or stock. Im on the side of more flow is better. (Everytime at work we have an overtemp on a piece of equipment, 1st thing we do is check flow.)

Did I miss the lower hose? Does it have the spring in it?

Do the temps go down with the heat turned on?

Did I miss if this was an automatic? Tranny putting heat into rad?

One other thing that has been mentioned here is the gauge. I had to replace an electric as it was reporting too high a temp. Said like 215* but laser on crossover said like 190*.


Not sure if added anything you havent done, but more eyes are always better

[Speargun]

I'll try a laser temp gun tomorrow

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[Sirrotica]

First of all are you sure the temperature gauge is accurate?

Is the A/C condenser old?

Look for bent fins, fins plugged with dirt in the A/C unit. If it's an old unit road dirt and insects etc. will stop a lot of air flow. Removing the condenser and thoroughly inspecting it as well as cleaning it may help your problem. A new triple pass aluminum radiator should have enough cooling capacity to cool your engine.

A chin spoiler will force more air through the radiator rather than letting it flow under the car.

A high flow thermostat, because the water will carry more heat to the radiator the more water that flows from the engine to the radiator.

High Flow Thermostats;

MotoRad High Flow thermostats are made of stainless steel and have enlarged openings to provide increased flow. MotoRad is the only thermostat manufacturer that produces true "High Flow" thermostats for today's higher performance engines. These parts also feature a triple-bridge design that increases strength, stability and reliability. High-flow thermostats also have a bypass valve that allows a small amount of coolant to circulate before fully opening.

If all of the above check out you may need to make a modification to have more capacity in the cooling system.

An auxiliary oil cooler will remove heat from the oil without having the coolant removing the heat from the oil.

I didn't see if your car has an automatic transmission. Divorcing the transmission cooling from the radiator will take some load off of the radiator.

IMO I don't like electric fans for cooling a Pontiac engine, as has been mentioned a belt driven fan will pull more air.

A few things to check if you haven't already checked them.

[ponyakr]

"...A new triple pass aluminum radiator should have enough cooling capacity to cool your engine..."

I've read that a triple pass can actually slow the coolant flow too much. Some say that a double pass will cool better than a triple pass.

I've never used either. So I can't say for sure.

[tom s]

you can also use it to look for hot spots around the engine.Thermo housing,at the water X over where it bolts to the head.Etc.Tom

[Sirrotica]

The triple and double pass radiators are used on oval track cars which are run a bunch harder than any street driven car and generate much more engine heat than a street driven car.

Thing is, the OP says a triple pass and a single pass radiator made no difference, changing the radiator again is not going to fix his problem, at least in my opinion.

I'm wondering if there may be a minor combustion chamber/head gasket leak into the cooling system. One of the tests to check for combustion gases in the coolant system may also be in order. Bubbles in a cooling system will not remove any heat and it doesn't take much gas in the fluid to cut the ability of the system greatly.

The man has thrown a bunch of parts and money at the problem so far and hasn't solved it. Time to find the source of the problem, not buy more parts, and spend more money.

Here's a good article on cooling system basics, good read and maybe it will ring a bell comparing it to the OPs problem:

http://www.pirate4x4.com/tech/billavista/Cooling/

[Ccass]

If you are running hot on the highway which is what I hear you saying, take the fans out of the equation. 50mph is plenty of air flow to cool the radiator. You either have a motor issue as pointed out above or more likely you have a combination of not enough volume of fluid or not enough pressure.


Suggestions:
Check your water pump pulley ratio. If it is wrong, that's your main problem.
Other Ideas:
Make sure you don't have obstructions in front of the radiator and all air flow is channeled into the radiator.
try removing the filter. It may be slowing the flow down to much
The combination of TriFlow and a Flow cooler water pump may be slowing the fluids down. Under certain circumstances, Tri-flow can create cavitation in the radiator. Essentially steam. Not good.
Important:
A 4 row aluminum radiator cools 15% less efficient than a two row aluminum radiator that has 2 1" tubes. There's also 1 1/8" and even 1 1/4" tube radiators. Take a look at every single high end radiator brand. All 'big' two row. ( I'm not saying that that Champion radiator shouldn't be able to do the job. It still should. I'm just reminding everyone that Champion has pulled off one of the best 'smoke and mirror' radiator campaigns of all time by taking advantage of our respect and admiration of the '4 row' radiator. For copper/brass, yes. Unfortunately, that's not the correct way to build an aluminum radiator.

[Speargun]

Originally Posted by Sirrotica

First of all are you sure the temperature gauge is accurate?

Is the A/C condenser old?
...
A chin spoiler will force more air through the radiator rather than letting it flow under the car.

A high flow thermostat, because the water will carry more heat to the radiator the more water that flows from the engine to the radiator.

High Flow Thermostats;
...
I didn't see if your car has an automatic transmission. Divorcing the transmission cooling from the radiator will take some load off of the radiator.
...
A few things to check if you haven't already checked them.

- I have an AutoMeter mechanical gauge & have tried 2 different electric senders for the FiTech. The FiTech reads 10* hotter, but the AutoMeter is dead on when the T-stat opens & closes and responds much faster.
- A/C condenser is brand new and clean.
- I have a chin spoiler & the upper diverter/baffle plates for 400/AC cars installed although I haven't added a lower baffle yet.
- Standard to high flow thermostat = no change.
- Auto trans with its own cooler.

Originally Posted by tom s

Have you put a lazer temp gun on the inlet and outlets of the radiator?It will tell you how much temp drop your radiator is giving you.How is the timing.A lot of pontiac over heating comes from retarded timing.Just hints.Tom

- I might be getting a 5*-8* drop from inlet to outlet.
- Any more advance on timing & I get pinging.
(10.25:1 (185-190 psi) on 92 octane)
Since timing was my #1 suspect, I've played around with it a bunch. From well retarded to 12* - 18* initial, with & without vacuum advance, & 28* to 18* mechanical stops all in by around 3200 rpm.

Originally Posted by tom s

you can also use it to look for hot spots around the engine.Thermo housing,at the water X over where it bolts to the head.Etc.Tom

The metal surfaces on the cross-over, T-stat housing, sending units, & radiator tanks are all around 170* to 190* with the water temp around 200* +/- 5*.

Originally Posted by Ccass

If you are running hot on the highway which is what I hear you saying, take the fans out of the equation. 50mph is plenty of air flow to cool the radiator. You either have a motor issue as pointed out above or more likely you have a combination of not enough volume of fluid in your system or the fluid is passing through the system too slow.

Suggestions:
Check your water pump pulley ratio. If it is wrong, that's your main problem.
Other Ideas:
Make sure you don't have obstructions in front of the radiator and all air flow is channeled into the radiator.
try removing the filter. It may be slowing the flow down to much
The combination of TriFlow and a Flow cooler water pump may be slowing the fluids down. Under certain circumstances, Tri-flow can create cavitation in the radiator. Essentially steam. Not good.
Important:
A 4 row aluminum radiator cools 15% less efficient than a two row aluminum radiator that has 2 1" tubes. There's also 1 1/8" and even 1 1/4" tube radiators. Take a look at every single high end radiator brand. All 'big' two row. ( I'm not saying that that Champion radiator shouldn't be able to do the job. It still should. I'm just reminding everyone that Champion has pulled off one of the best 'smoke and mirror' radiator campaigns of all time by taking advantage of our respect and admiration of the '4 row' radiator. For copper/brass, yes. Unfortunately, that's not the correct way to build an aluminum radiator.

- Pulleys are from CVF Racing I bought in a group buy here several years ago &, as far as I know, are standard ratio.
- The only obstruction in front of the radiator is the grill & AC condenser.
- I had the same issues with both radiators before I added the filter. The filter is a see through type and and it looks like the flow is plenty fast.
- Due to the low temp drop across the radiator, 5* +/-, it almost acts like the flow is too fast, but it could also be due to cavitation. ???
I have an old 4 row brass radiator I can try, but I'm still suspicious of the timing and will go back & try to nail that down next/again.
I'll also see if I can find a shroud for the car & try a stock fan.

Thanks for all the input!

[ponyakr]

"...I'll also see if I can find a shroud for the car & try a stock fan..."


Most say that for max cooling you need a 7-blade clutch fan, with a good clutch, such as the Hayden Severe Duty #2797.

http://www.ebay.com/sch/i.html?_odkw...an&_sacat=6000

https://www.amazon.com/Hayden-Automo.../dp/B000C3F3D4

Some prefer a 7-blade flex fan, such as the Flex-a-Lite 1818.

http://www.ebay.com/sch/i.html?_odkw...an&_sacat=6000

https://www.amazon.com/Flex-lite-181.../dp/B000CNHFOE

[tom s]

I don't have a clutch fan on any of my 4 cars and have no cooling issues.Tom

[Ccass]

Originally Posted by Speargun

-

1. Pulleys are from CVF Racing I bought in a group buy here several years ago &, as far as I know, are standard ratio.
2. The only obstruction in front of the radiator is the grill & AC condenser.

3. I'll also see if I can find a shroud for the car & try a stock fan.

Thanks for all the input!

1. standard ratio is not enough info. You should check the ratio of your crank pulley vs your water pump pulley. An incorrect ratio may not be creating enough pressure to keep the temps down in the system. Remember that todays low octane fuel creates more heat. Pressure reduces heat. You want more pressure.

2. you should have at least 1" between the condenser and the rad to allow the radiator to have enough air flow.

3. While I am a big proponent of factory fans, clutches and shrouds, your highway overheating tells me none of these issues are at fault here. However, they'll certainly help your stop and go driving temps.

[tom s]

Will take a look when I get home,as I remember I get a pat bigger drop 20 plus drop on mine.It will be a few days.Tom