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Cooling woes :(

  
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Cooling woes :(

 
barneyformula barneyformula
Addict | Posts: 3298 | Joined: 01/07
Posted: 07/27/13
12:41 PM

Ok gang, I know we've all been through this many times but I have to ask what I'm missing here.
Some history first: My 79 Formula has had overheating issues since I first started driving it 6 years ago. When I first bought it, I removed the 454 BBC that came with it and sold it. Installed the 1975 350 from an Esprit after changing all gasket, frost plugs and cam/lifters/timing set. The cam was an old Crane 272 with .450" lift, nothing huge, 5C-4 heads, stock intake and exhaust manifolds 2.25" duals. Q-jet, HEI, TH400, stock clutch fan and three core rad, new water pump with new transfer tube seals and the divider plate tapped down for tight clearance. Car always had cooling issues on the highway with this setup, would make huge amounts of heat at highway speeds (3000rpm max) but would cool down in town. Would get hot enough to vapor lock the carb and stall out. Changed to a new 3-core Spectra Premium rad (used an identical one in my 80 Camaro with a 355SBC and never went over 190F). Same issues, flushed block and avoided highway driving! Not the way to enjoy a toy.
Fast forward to this year: Installed rebuilt 455 (.020" over, cast flat-tops, 5C-8 heads, Performer intake and 750 carb, Lunati 00071 cam/lifters/springs/timing set, COMP Magnum roller tip rockers, Hedman headers with 2.5" Flowmaster exhaust, 2400 B&M converter, same trans and rad, replaced fan clutch with new, new water pump and seals), also finished installing Vintage Air a/c, now has condensor in front of rad. Same issues, runs hot on highway 220+F, confirmed with mechanical guage and infrared temp gun. Tried 7 blade flex fan...no change, added a homemade chin spoiler to force air thru rad...better but not much. Found rad rubber insulators installed backwards causing a gap between rad and shroud. Installed them correctly and it runs consistant 195F on highway on 80F day, but severely overheated (240+F) while sitting at a traffic light waiting thru 3 green lights for my turn to turn left with no advance green. Carb vapor locked and stalled just as I made my turn with an oncoming 1-ton Ford and landscaping trailer bearing down on me!
That was the last straw (or so I thought!) and I ordered a 3-core aluminum rad from ebay (Champion cooling systems, guaranteed to cool 850hp, read lots of good comments on several forums and the price was right). Installed the new rad yesterday, fit great and appears to be a quality product (similar construction, tube and fin size to the rads I'm used to on diesel tractor-trailers). Guess what??? You got it....it still runs hot! Idling with a/c on it hit 220 after ten minutes of running and slightly higher before I took it for a drive with a/c off and cooled it down to 200F. After shutdown, the temp hot-soaks to 240+ on the mechanical guage!
Drove to town last night for a dinner date and it ran 200 on the highway at 75mph in 80F ambient air. Coming home after dark when the ambient was more like 60F, it ran 185-190 running at 60-65mph.
So in summary, it currently has a 160F t-stat, 7 blade flex fan, BIG 3-core aluminum rad, a/c, new stock water pump/seals with divider plate gap adjusted to less than .120", 50/50 mix of antifreeze/water, has spring in lower rad hose, stock upper and lower pulleys (same as three other Pontiac V8 engines I have). I'm at the end of my rope here. The next time it overheats I'm afraid the fire department may have to cool it off for good when I set fire to it! I've even been heard to mutter about replacing the PMD 455 with a SBC-355 to sell it so I can be rid of the problem for good. This was supposed to be a fun car built in honor of my late wife who bought it for me, but I'm so incredibly frustrated with it that I'm considering parting it out and using the body shell for my dirt-tracker and crushing the rest. Help me out guys, what have I missed? Frown  Mad
Steve  
A little help... 'cause we don't all have to learn the hard way!

70bird 70bird
Guru | Posts: 1064 | Joined: 02/13
Posted: 07/27/13
02:02 PM

Hello



I'd personally do the following for starters.


Your thermostat rating is too low, it's staying open all the time. Put a 185-192 in it. This alone will not fix it.


Buy a fixed 6 blade fan from flex-lite p/n 1717P. The flex fans don't work well. This fan will kick you fans behind.


Fan should be around 1/2-2/3 way in that particular shroud.


Change coolant mix to 20% antifreeze, 1 bottle water wetter then deionized or regular water. This will not only drop your average tempos by 10-15 degrees it will cool down faster when accelerating from a stop.


Your champion rad has 3/32 wide tunes instead of the std 1/8 if I remember right which means it holds about the same amount of water as a 2 row with tubes the same length but 1/8" wide tubes. They may also be less than 1/2" wide. Can't get this info. A US made t row with 1" on 3/8 center "high efficiency" rad is far superior to the Champion even though you have more surface cooling area in the tubes on the Champion.


CHINESE MADE - By the way, it's made in China [or Taiwan]. This is actually a good thing in this case because the tube material is thinner than the US ones and therefore cool better than a comparable US made one.

"Our aluminum radiators also have a high density core, boasting with 25% more rows than other aluminum radiators"

What exactly does "boasting with" mean? Perhaps they need another translator to write their ads.


US MADE RADS - Here's an example of some Northern rads. Around $350.00 for a 2 row 1" tubes on 3/8 centers. US Radiator also makes some under their Cool Craft name.

http://www.hrperformanceproducts.com/gmradiators.html

http://www.coolcraft.com/


RETURN POLICY - I have seen some places that return the Champions if you are unhappy with that. It might be an option if you determine yours is not big enough.


"Drove to town last night for a dinner date and it ran 200 on the highway at 75mph in 80F ambient air.

That's not horrible but still warmer than it should be, plus when it's 100 out your car might be 220. Just the coolant and thermostat change will help that considerably.

If it still does this with coolant ratio change and a thermostat between 185-192 then your rad is likely too small.


VAPOR LOCK - Lowering the float level might help depending upon where it is set now. Too low will create a lean condition.  

waynep712222 waynep712222
Enthusiast | Posts: 310 | Joined: 03/13
Posted: 07/27/13
02:03 PM

lets work on the vapor lock issue first... as that might be causing some of your overheating issues...


create a loop of fuel hose between the fuel line and the pump inlet..

install an OE style Inline fuel injection type of fuel filter there in the loop...  

with a cold engine.. disconnect the HEI...  disconnect the fuel line to the carb.. either at the carb inlet or the fuel pump outlet..

extend the output hose/line into a 2 or 3 liter clean clear plastic bottle..  have somebody crank the engine for 15 seconds...

this will push fuel thru the fuel pump at high speed.. you should have almost a PINT of fuel in those 15 seconds..

be sure to watch the pulses of fuel as it comes out of the pump..   if the pulses diminish. you might have either a hole in the side of the fuel line.. or a clogged or crushed fuel link.. perhaps a linked line..  a hole will show up as bubbles in the pulses of fuel into the plastic bottle..

why i want you to install a fuel injection type of inline filter is to catch any super fine sediment that goes right thru regular fuel filters... only the fuel injection types have fine enough elements to catch it..

the sediment causes additional issues..   it holds the check valves in the fuel pump slightly off their seats.. this reduces pumping abilities of the fuel pump..    it can lower the pressure between the fuel pump and the carb.. so when the fuel line get hot there.. it boils at the lower fuel pressure and pushes backwards thru the fuel pump check valve.. the fuel pump cannot pump vapors..

i have found some fuel pumps.. that i could take the line off at the carb and blow bubbles in the fuel tank... there should be 2 check valves in the pump to prevent that.. one to prevent the fuel from the inlet from flowing backwards and the other to prevent the fuel in the line from the carb from flowing backwards..

ps... stick a big magnet to the bottom of your fuel tank... if you cannot get one inside until the next time you have it down to work with the sending unit... then drop at least one super magnet into the tank.. it will collect the sediment and keep it out of your fuel system..  

Torqued400 Torqued400
Addict | Posts: 2479 | Joined: 10/08
Posted: 07/27/13
05:14 PM

My ole Bird motor liked a little heat Laugh
Hope you get it figured out so can hear that Lemans. T  
"We build Excitement"

Pontiacman8 Pontiacman8
Moderator | Posts: 5770 | Joined: 02/08
Posted: 07/27/13
06:11 PM

Steve I had a some what similar problem with my 301.
It would over heat at idle and I found the problem to be that the carb. was to lean.
Have you tried richening up that 750 carb?  
Engine builder,self taught auto body guy.
Horsepower sells engines and torque wins races

Pontiacman8
Pontiacman8
Pontiacman8

barneyformula barneyformula
Addict | Posts: 3298 | Joined: 01/07
Posted: 07/27/13
08:36 PM

OK, I'll try to answer these in order.

70Bird: The fan is in it's proper position, everything is in stock position.

Yes, I know it's Chinese. I'm trying to sell this thing and didn't want to spend twice as much for a BeCool or Griffin rad. Like I said the tubes and fins are similar size to the ones I'm used to on 15L diesel highway trucks that are pulling 100,000 lbs down the highway, so I'm pretty certain it's not rad design, this thing should be vastly more than adequate for my 350hp 455.

Fan type: I have one more to try, a fixed 6 blade off a 67 400 from a Grand Prix, looks like it should move more air than either the factory flex or clutch fans.

T-stat, I'll give a 195 a try although that seems counter-productive but I do get the theory of letting the coolant sit in the rad longer to cool off.

Vapor lock: only happens when I have to sit in traffic for an extended period and the engine makes so much heat that it boils the fuel.

Wayne and Pman, the entire system is brand new this year, new tank (old one was corroded and filling the old Q-jet and filter with silt, I did have a magnet on that tank. It has new lines, new fuel pump, inline EFI style filter, rebuilt the carb to factory Edelbrock specs. Jetting is bang-on. It has plenty of fuel flow and will pull strong from a dead stop to over 120mph without ever starving for fuel. It pulls like a freight train on steroids! (I love the wide-eyed look from my passengers when I get on it!) I only buy my gas at Sunoco, 91 or 93 octane.

I had to host a party for my son's 12th birthday today so I didn't have time to work on it, maybe tomorrow. I'll see if I have a 195 or 180 stat in stock and try it along with the fixed blade fan.
Thanks for the input guys.
Steve  
A little help... 'cause we don't all have to learn the hard way!

70bird 70bird
Guru | Posts: 1064 | Joined: 02/13
Posted: 07/27/13
08:59 PM

Don't forget the reduced 20/80 coolant mix with water wetter. 100% guaranteed to help over the std 50/50 mix

What is your mix now?

Water wetter is good for around 6-7 degrees reduction in average temp plus and quicker cooling.

Reduction in antifreeze is good for around 7-8.  

Pontiacman8 Pontiacman8
Moderator | Posts: 5770 | Joined: 02/08
Posted: 07/28/13
05:45 AM

I would still try richening up the idle on the carb a little to see if it helps if you haven't already.  
Engine builder,self taught auto body guy.
Horsepower sells engines and torque wins races

Pontiacman8
Pontiacman8
Pontiacman8

idrivejunk idrivejunk
Addict | Posts: 4987 | Joined: 12/09
Posted: 07/28/13
08:50 AM

Steve, basic questions here just to spur thought.

Have you pressure tested the cooling system and cap?

Do you use an expansion tank?

Does it puke?

Where do you keep the water level filled to, how far below the cap?

Is the temp sensor on the intake or head?

Using an internal trans cooler or external or both?

Got a heater valve or the Pontiac heater hose nipple with the bimetal flow limiter inside?

Fan clutch selection and performance is important, worth a look and test.

Confirm fan is not installed backwards.

Ever try a different gauge?

Got your intake heat passage blocked?

My EPS / Performer will boil fuel without a spacer, about three minutes after a summer shutdown.

I've seen old fuel hoses suck shut under demand but only when hot and soft.

Maybe you could open up the "Formula" scoops and get some ventilation?  
idrivejunk

Torqued400 Torqued400
Addict | Posts: 2479 | Joined: 10/08
Posted: 07/28/13
02:18 PM

I can give ya sum hillbilly stuff,

1) Pull it up on a hill to fill it up warm. Just to make sure it's full.
2) drill some 3/16th holes in the thermo. Blush
3) Definitely more blades on the fan.

Grin T  
"We build Excitement"

barneyformula barneyformula
Addict | Posts: 3298 | Joined: 01/07
Posted: 08/06/13
05:26 PM

Ok, the story so far: swapped the 7 blade flex fan for a 6 blade, fixed pitch fan that came with the 67 400 I bought a while back, seems a bit better on the highway but still goes 220 idling without the a/c on after about 5 minutes. Swapped the thermostat for 180F (was 160F) and replaced the coolant I drained out with straight water, so likely only 20% antifreeze now. Of course the ambient temp has dropped this week so it's harder to tell if I'm making progress but it idled for 10 minutes and was only up to about 210F. I did richen up the idle mixture a bit but it didn't help, just loads up the plugs when idling. I'll have to wait for the warmer weather to come back, forecast says maybe next week. With any luck, I'll sell it while it's cool and not have to worry!
Steve  
A little help... 'cause we don't all have to learn the hard way!

70bird 70bird
Guru | Posts: 1064 | Joined: 02/13
Posted: 08/06/13
05:48 PM

Hello


In your particular case, just short of a better rad it will be a combination of all the little things adding up that will get you as close to where you want to be as possible imo. The details are important.



is it a high perf eng?

what is your ign timing at idle?

please advance it until it starts to barely stumble/miss, then retard it 6 degrees. Some people seem to be able to drop 15 degrees at idle doing this. Of course it would likely require a connection to straight manifold vacuum in the end to use this as a full time setting especially if it diesels upon shut down but we'll see. It's a free, easy and fast test.


THERMOSTAT - "Put a 185-192 in it. This alone will not fix it."

"Swapped the thermostat for 180F (was 160F)"

Uh oh, close but no cigar. i knew a 180 wouldn't work, lol. It is still staying open. I suggest a 195 now. I was hoping your rad would hold the 185 but since it won't hold the 180 the 185 is too low too. It's kind of a balancing act with a marginal cooling system. If your rad was a 6" thick aluminum one with a late model oem electric fan you could easily run a 160 thermostat, lol.


FAN SHROUD - Fan should be around 1/2-2/3 way in that particular shroud, is it?



FAN

"Buy a fixed 6 blade fan from flex-lite p/n 1717P. The flex fans don't work well. This fan will kick you fans behind."s

"swapped the 7 blade flex fan for a 6 blade, fixed pitch fan"

I it oem?

Is there a part number on it?

can you post a photo of it?

the one i recommended is the biggest baddest fixed fan one can buy. i don't know if there was a 6 blade oem.


COOLANT

"Change coolant mix to 20% antifreeze, 1 bottle water wetter then deionized or regular water. This will not only drop your average tempos by 10-15 degrees it will cool down faster when accelerating from a stop."

"replaced the coolant I drained out with straight water, so likely only 20% antifreeze now."

Not good to guess at these things when your engine overheats imo, plus you forgot the water wetter.

I would go to 10% anti freeze with water wetter.

There is occasionally a method to my madness.



What happened with your "vapor" lock? is it gone maybe because the weather simply isn't as hot as it was last time?  

ROWSLEY ROWSLEY
Guru | Posts: 981 | Joined: 07/11
Posted: 08/06/13
11:23 PM

steve sounds like you have enough air flow through the radiator what about water flow?

pulley size? i think the flow may be too slow sence it cools down at speed.  
76 455/4spd TRANS AM
69 GRAND PRIX 455/5SPD

barneyformula barneyformula
Addict | Posts: 3298 | Joined: 01/07
Posted: 08/07/13
04:08 AM

70Bird, aside from the cam/intake/exhaust, this is all stock stuff. 8.8:1 CR, iron heads, 91 octane. The full engine specs are listed in the first post. Can't get water wetter here, nobody knows what it is! I could order it but it will take a while to get it. As for the antifreeze mix, it was 50/50 and I drained out better than 1/2 and replaced it with straight water. it's getting pretty thin, I'll have to drain it and replace it before winter or I'll have a cracked block! The pulleys are the stock pulleys, same as all 5 Pontiac engines I have collected, the fans have all been stock GM fans of different types. The first was the original clutch fan, then a new HD replacement clutch on the original fan, then a 7 blade flex off a pickup truck, now a 6 blade, fixed pitch fan off the 67 400 330hp that I just bought. Each fan has been capable of moving a vast amount of air.
What bugs me is that this combination is not an extreme build, Pontiac installed 455's in Firebirds with the same rad that I was using, same fans, same waterpumps, 50/50 mix, same shroud and so on and was able to sell them with warranty so you know they weren't prone to overheating. Why is this thing so hot all the time? It only vapor locked when it got to almost 240F, the underhood temp was so hot that it boiled the fuel while sitting thru 3 or 4 traffic lights waiting for my turn to make a left hander.
My friend has three restored GTO's with 10.5:1 engines, a mildly built 78 TA W72/400 and a 9.5:1 350 in a 81 Espirit running on 93 octane and uses the same stock style cooling systems that I started out with (rad/fans/pulleys/antifreeze/160F stat) and his cars never get over 200 degrees, he's stumped too!
In my opinion, there is no reason for me to have to butcher the appearance of this combo with electric fans or other aftermarket stuff, it flat out should not be running this hot, but it is!  
A little help... 'cause we don't all have to learn the hard way!

waynep712222 waynep712222
Enthusiast | Posts: 310 | Joined: 03/13
Posted: 08/07/13
07:45 AM

the 192/195F thermostat should help even more..

the 79 formula fan shrouds are huge.. is yours intact???

what about ducting in front of the radiator... its been a LONG time since i was under a 79 formula..

i seem to recall that the 79 *** and Formulas are bottom breathers.. as in.. the air flow thru the radiator is not thru a grill but up from under the front bumper... usually piled up to increase air pressure in front of the radiator by an Air dam directly under the core support..  when the air dams are damaged or missing the air flow is built up in front of the cross member and this tries to push the air forward thru the radiator..  causing overheating at sustained speeds above 55 mph usually..

my sister.. (rip) had an 85 Ta that would overheat above 57MPH.   it was just the air dam that was broken off .. i actually hooked up an HVAC air flow pressure gauge and the pressure behind the radiator was higher than in front of the radiator above 57 MPH..  when i installed the air dam . cooling issues vanished..  

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