[oscodagp63]

you guys talk about a water pump with a cast iron impeller. I have a 73 455, I cannot locate any water pumps with cast iron impellers. cordone or otherwise. does anyone have a source?

[1967Tempest]

You should have an 11 bolt water pump. If so you should do all three.
1. Water pump
NAPA pump part #: DPW1301280
2. New Sleeve assembly.
Can still be ordered through GM Part # 9796347
3. Spacer plate clearence mod
Try to get the clearence as close as possible. .025" or under

The reason I say all three is because you are going to have the whole front off anyway, so might as well do it all the first time. Any questions email me or PM me. I just finished this and through the help of this forum and a lot of emails from Pontiacman1970 (Thanks again), I think that I have solved my issue.

Dave

[1967Tempest]

After finishing it all up she ran 150 miles from CT to NJ and never got over 185!!!!! After I got her home I adjusted the electric fan relay for the front fan and she ran for an hour at idle and never got over 171. AHHHH Very nice to haul ass down the road and not look at the gauge. Thanks for all of you help

http://www.youtube.com/watch?v=Z49Ag7QtEs8

[GTOGreg]

My latest project car has been running hot, mostly at idle. I decided to take my water pump off as I was in the area doing other work. Not sure what I found, but it looks different than anything I have seen in this thread. It almost looks modded, although i'm not completely sure of the history. What should I do, change it or stick it back on? It does have divider plates BTW, they are just not in the pic.

This is a '67 400 BTW with the old style pump.

[george kujanski]

I think that's similar to a Flow-Cooler. Put it back on but make sure the clearance from the welded plate to the internal housing is a minimum to minimize leakage around the impeller. If you can, measure the existing clearance to add data to our database.

George

[GTOGreg]

Thanks George. I closed the gap from around .150 to about .040. Hope to see some difference. Will report back...

[CLEL01]

Just wanted to say thanks to all who posted info on tweaking the water pump plate for close clearance to the impeller.

This is really the first thing I have done to my GTO myself. So after reading most of the posts, I disassembled the pump. Adjusted to plate from 0.250 down to about 0.050. Before tweak, water flowed thru the radiator slowly at idle, now there is great flow. And "normal" temp has dropped from 215 to 190 on a very hot day. Added tip, buy two gaskets so when you find the first reassembly leaking, you have a back up without another trip to the parts store!

Jeff C

[GTOGreg]

OK, so after doing the mod my temps dropped from about 230 max to 210. Today I added a coolant recovery system and lost ANOTHER 15, so I'm topping out at 195 on a 90 degree day with a 180 thermostat. The amount of air in the system was staggering - it was bublling steadily for 5-10 minutes initially. Before adding the recovery it would boil out to the ground and then contract (vacuum) and induce air into the system. It must have sucked up 3 quarts of water upon cooling down. Oh, and I added some vinyl around the rad to close some gap between rad and shroud.

The attached pics show before and after on the divider plate. Down from about .150 to .40.

[Tom Vaught]

Even though it is not stock appearing, a lot of the Evans Cooling water pumps have a bleed walve installed at the top of the water pump. I used to do the same thing with a drilled and tapped hole at the top of the aluminum timing cover housing. Once I bled all of the air out of the water pump housing of the timing cover I would use a simple bolt and a Holley Fuel Bowl Screw Gasket to seal the bleed. Cheap, works like a charm and eliminates the trapped air in the timing cover/water pump.

I doubt is that trick will have the responses of George's clearance mod but post up if you try it and it works. You can do the drilling if the pump is off and you stuff a couple of rags in the open area of the timing cover to catch the aluminum chips from the drilling.

Tom V.

[400 4spd.]

Originally Posted by CLEL01

Just wanted to say thanks to all who posted info on tweaking the water pump plate for close clearance to the impeller.

This is really the first thing I have done to my GTO myself. So after reading most of the posts, I disassembled the pump. Adjusted to plate from 0.250 down to about 0.050. Before tweak, water flowed thru the radiator slowly at idle, now there is great flow. And "normal" temp has dropped from 215 to 190 on a very hot day. Added tip, buy two gaskets so when you find the first reassembly leaking, you have a back up without another trip to the parts store!

Jeff C

That last sentence describes my week! I located a pump with a cast impeller and swapped it onto my '72 Grand Prix a few nights ago. Reduced the divider plate clearance, the whole deal. I wrapped it up (or so I thought) at 2 AM Wednesday morning. After replacing the coolant, it leaked between the timing cover and block. Just what I had feared would happen. So, I pulled it down to the block/timing chain and started over.
I'll post results after I can get some driving time in under normal conditions.

[snakepod]

Any news on the final outcome, Steve? Today looks like a nice hot day for testing!

[george kujanski]

Yeah, Tom V., but his entire thread is not getting the attention that the hot chick of the day thread is getting in the Clubhouse forum!!!!! Good idea tho.

George

[400 4spd.]

Originally Posted by snakepod

Any news on the final outcome, Steve? Today looks like a nice hot day for testing!

After driving it for a couple of days with temps. in the mid 90's, I feel like the pump change has knocked off 10-15 degrees. It never went over 190 sitting in traffic, 175 - 180 at 70 m.p.h., and I can live with that.
Next on the list, a carb. change.

[snakepod]

Let me know when you're ready. I have a test q-jet in mind

[68GeeeTO]

I have had a running HOT condition for the past 3 years on a 68 GTO with factory A/C.

Thanks to this sticky the Goat is fixed, all my running too hot, puking out the over flow, especially with the A/C ON are now gone. The car has never run this good since I’ve owned it.

When all is said and done, I found a stamped steal impeller water pump, with a ¼ inch gap, impeller to divider plate, a bad clutch fan, and a leaking vacuum canister.

Thanks Geroge Kujanski ur the man!

p.s., I posted some pics in the lobby of my GTO.

This is kinda of a repost of the lobby, as an after thought it belonged here too.

[george kujanski]

We're doing our part to reduce global warming.

George

[Tim john]

GTO GREG, That pump of yours is a "Flow Kooler" for I have the same exact one form Butler Performance. I am having high temp issues with my fresh engine (230 ish at highway speeds). Engine paint is beautiful and I just hate to scratch and mess things up but the alternative is by far more painful. Looks like I am going to tear back down.

Tim john---

[General Z]

Ok, guys, I have tried all of this stuff, and then some, and it only seems to get hotter?

1970 455 in a 67 Firebird. I don't know what the radiator is out of, but it appears to be bigger than stock. I had a water pump with a stamped impeller and had already adjusted the plate to fit with this pump. Then, I got a cast impeller pump, and tried to bend the plate back a bit, because now it was way too close, as in, it was touching. I could only bend it back so much, cleanly, and thought I had it just right. Then, when I put the pump on the car, the I realized that the impeller was rubbing on the plate a bit, but left it, figuring it would adjust itself pretty quickly.

This really didn't make me any cooler. It was running around 205 or so. Then I got thinking that for some reason, the car had a 7" crank pulley and a 8" water pump pulley, so I got a 8" crank pulley and a 7 1/8" water pump pulley. I also installed a spring in the lower radiator hose.

After doing this, the car actually ran even hotter, getting and staying over 210.

I have a Milodon high flow 160 degree stat and a DC Controls 18" electric fan with the potenimeter meter built in.

On paper this thing should be as cool as a cucumber right?

One bad thing I noted was that when I drained the coolant to put the spring in the lower hose, after settling the bucket of coolant had an oily substance on the surface. Actually, quite a bit. I pulled the oil drain plug, and let a little oil drain out, but didn't see any coolant.

The oily substance looks more like trans fluid. My trans fluid does seem a bit high, but the fluid on the dipstick looks great.

One other thing I noted while installing the new pulleys, was that the water pump seemed to still rub the backing plate, while turning it by hand.

Since technically, the only thing that changed was putting differnet pulleys on, which sped up the water pump, I am thinking that maybe there is now too much flow and the radiator can't keep up? Maybe I need a non high-flow thermostat, or a hotter thermostat, like a 180?

Thanks guys, stressed and depressed here.

[General Z]

Ok, let it cool overnight, and then opened the radiator cap. No oil on top of the water, but it needed a little bit of coolant, say maybe 2 cups. I topped it off, and then went for a test drive with the ambient air temp at about 80 degrees. I was driving around at about 25 miles an hour, with the temp staying nice and cool. Then, when it started to climb, and got up to a little over 200 by the time I pulled into my garage. This was after myabe 4.5 miles of driving at speeds less than 50 miles an hour. When I did get it up to about 50, I noted that the coolant did not come down in temp.

Isn't staying cool, then getting warmer and warmer, and then never coming back down similar to what one might find with no thermostat?

Perhaps once the high flow 160 opens fully, and I am circulating all the coolant so quickly, that it never can cool back down?

Any ideas?

[Tim john]

General, Pull a spark plug and see how its burning, if its too white it may be to lean, up the jetting a size or two, this should also cool the engine down some what. I am still battling my situation and am working on a few things as we speak...Details with photos to follow.

Tim john---