[fiesta62]

hi, i have done everything to try and keep my car cooler at idle, it gets up to around 200 at idle, not critical i know but car pings at around 190 , so i need to keep temp 190 or less, car is a non ac, i read that the AC 68 gto used a 5-11/16 inch water pump pulley, my 67 has a factory 8 inch water pump pulley, 67 and 68 used the same water pump, so i figure i could put the 68 pulley on my 67 to speed up the pump, i would be going from 8 inch down to 5-11/16 inch, has anyone done this with any success ?......and if anyone has a 68 5-11/16 inch pulley let me know i would like to try it....thanks

[68 Firebird]

Yes that helped my car with cooling. Think my waterpump pulley
is 5.5 and my crank is 7.25. Remember the ratio was like 133% compared
to stock 90%.

Basically went from non AC setup to an AC setup for improved cooling.
That and a Hayden HD fan clutch and a 7 blade fan from a TA with auto and AC!!

Good Luck

Gerry

[fiesta62]

great that's what I hoped, now just got to find a 68 pulley, lots of 8 inch ones around but the 5-11/16 are scarce but they do come around I missed a few on ebay recently....

[68 Firebird]

I bought mine from March systems. They do aluminum pulley systems.
Was able to buy just the WP pulley and I painted it black for a stock
appearance.

Think it was about 70 or so bucks

Gerry

[chrisp]

What type of fan are you using ?

[fiesta62]

Originally Posted by chrisp

What type of fan are you using ?

well i had the 17. 5 inch factory clutch fan on it, but then took it off and installed the larger ac shroud with a 19 inch flexalite fan....i didnt see much improvement if any, so just this week spent a lot of time sealing off all gaps around shroud....and bought a new derale 6 blade flex fan, its there deepest pitch they make and they say it will pull the most air over rad at idle, i just finished this yesterday and also installed a 160 thermostat....today is the test drive, fingers crossed

[pugslyx234]

Been reading posts could it be carbon-ed up in the heads/pistons creating hot spots which would cause pinging just mez 2 %

[fiesta62]

Originally Posted by pugslyx234

Been reading posts could it be carbon-ed up in the heads/pistons creating hot spots which would cause pinging just mez 2 %

dont know about that, engine was rebuilt by previous owner about 25000 to 30000 miles ago....our next trick i think is to go a even smaller water pump pulley....

[68blackbird]

I tried all the things you have stated, 400, #16 heads aluminum rad, water pump, clutch fan, timing, jetting. I tried everything. Converted to run on e85, it does run cooler on e85 but still goes to 205 at idle. Added smaller water pump pulley and larger crank pulley. And it's better. But with all the above changes the car will not stay at 185 in all situations. I have not had the heads off the car to verify. But I have concluded that my pistons are to far down below the deck for proper quench. All this to say, before you continue to drive yourself crazy and spend more money. You might want to pull one head just to see where you are with the deck height. At least if you find your pistons 0.040 in the whole you know what's going on with the engine and anything you do is a bandaid.

So what am I doing. I have a 455 on the stand in the garage 9.25 credit with iron heads and the pistons are out of the deck .004. It will run pump gas all day and stay cool.

Rich

[fiesta62]

hi..well i am now thinking about installing the later 69 water pump, its a better design, so i am looking at various suppliers, some do kits so hopefully i can find everything needed, my mechanic feels the 67 water pump design is not good and at this point we dont have many options left except maybe installing aluminium radiator but for now we lean towards a better water pump....

[68blackbird]

Originally Posted by fiesta62

hi..well i am now thinking about installing the later 69 water pump, its a better design, so i am looking at various suppliers, some do kits so hopefully i can find everything needed, my mechanic feels the 67 water pump design is not good and at this point we dont have many options left except maybe installing aluminium radiator but for now we lean towards a better water pump....

can your mechanic tell you where the pistons are in relation to the deck?

Rich

[george kujanski]

Here we go again.......so if slow flow gets rid of heat faster, slowing down to zero flow must be the best.....unless, of course there is some sweet spot, meaning we need to run the engine at this particular sweet spot.........

Gang, this is all bunk, faster water flow, faster air flow will remove heat better....look at the manufacturer's heat transfer curves on ANY heat exchanger.....physics does not change.

George

[GT182]

I was asking to see photos of the 8 bolt water pump with a side view of the impeller. Then we could tell if the impeller's contour is your problem.

Have fun with the electric Stewart water pump. I'm not trying to be a wise a**, but IMHO you're just wasting money and adding $s to your mechanics pocketbook. It's your choice. Good luck and I hope it works out ok.

[fiesta62]

Originally Posted by GT182

I was asking to see photos of the 8 bolt water pump with a side view of the impeller. Then we could tell if the impeller's contour is your problem.

Have fun with the electric Stewart water pump. I'm not trying to be a wise a**, but IMHO you're just wasting money and adding $s to your mechanics pocketbook. It's your choice. Good luck and I hope it works out ok.

my original pump is on car so I cant do pics....I will be fitting the electric pump soon so will know if I wasted money or not....but just think if this does actually fix the issue then all these guys with heat issues can just fit one and all is good,....the pump has a switch so it can be switched off at any time as its a flow thru design....so if your stuck in traffic on a hot day just switch on another 55 gal a minute.......too easy,,,

[fiesta62]

Originally Posted by george kujanski

Here we go again.......so if slow flow gets rid of heat faster, slowing down to zero flow must be the best.....unless, of course there is some sweet spot, meaning we need to run the engine at this particular sweet spot.........

Gang, this is all bunk, faster water flow, faster air flow will remove heat better....look at the manufacturer's heat transfer curves on ANY heat exchanger.....physics does not change.

George

yep so smaller pulley and the electric pump doing 55 gal a minute should help faster is better....

[Old Goat 67]

yes I know is a lot but I really don't care....if it don't fix it I have wasted more money and time....but if car runs at I hope around 180 all day long then that $450 will be quickly forgotten, wouldnt u agree.....

I'm sorry, no.

All it cost me was $30 for a CORRECT water pump with a CORRECT impeller and I run at 180° all day long, even with AC on in 100° temps.

Charles

[fiesta62]

well I cant argue with that, u got yours working right...but I have had my pump modified and plate welded inside on top of the impeller to be similar design to the flow cooler pump...so the blades are closed in just as the flow cooler pump is....so I cant see any issue with my original pump, we have done that and everything else, so came to the point of thinking the pump is a poor design so am trying the electric pump, .....correct me if I am wrong but pontiac changed the design of the pumps in 69 why would they do this, only reason could be is that the early design was not cooling good enough...they also used smaller water pump pulley size in 68 to pump water faster, another indication that the original design 67 pump was not perfect...though only my thoughts I'm no expert, I'm over the whole thing if this electric pump works I will be a happy camper...

[indymanjoe]

Originally Posted by Old Goat 67

I'm sorry, no.

All it cost me was $30 for a CORRECT water pump with a CORRECT impeller and I run at 180° all day long, even with AC on in 100° temps.

Charles

This all day.I doubt any of our pontiacs when new with A/C on, in Arizona ever overheated when new.Sloppy mechanics in the day and crappy rebuilt water pumps is the reason they get hot now.(Most of the time)LOL

[george kujanski]

Welding on the plate is ok, but if the plate and the impeller itself has too much clearance to the inside if the internal housing, the coolant will recycle around the impeller and internal housing instead of being forced into the cooling jackets on each bank. The welded plate alone won't fix a large clearance.

The additional plate on a flow cooler doesn't address the clearance issue either, looks fancier tho.

The pump works by drawing fluid thru the center hole (in OLD Goat's left pic) and increasing the pressure out towards the impeller vane tips. With too much clearance, the fluid from the higher pressure area will go back to the suction side and you get recirculation, instead of drawing fluid in from the radiator. The clearance needs to be minimized. If you already have that, fine.

George

[fiesta62]

my mechanic did all the plate clearance , checked and rechecked...we went thru all that , so we were scratching our heads just without any idea what to do next...