[bb400ho]

i have a 63 tempest 326 that i want to replace the water pump on. as far as i know its the original engine. it has a 4 bolt water pump. all i can find for the 326 is an 8 bolt pump. rock auto has the 4 bolt listed for a 63 on the 389. they have 2 choices, one is the stamped impeller that they say turns counter clockwise (thats the junk one right?) and one with a cast impeller. if its a 4 bolt made for an 8 cylinder will it fit the 326?
thanks bryan

[Bill Hanlon]

The "reverse" impeller model is an urban legend. It is just a different design. I've used both the stamped steel and the cast impellers on my 4 bolt pump daily driver 57 V8 for many years.

[mechanickeith]

Bryan, as Bill said the reverse impeller statement is bunk. If the 4 bolt pump that your supplier has, has an impeller that looks like the 4th pump in the pictures I posted, then it will work fine. For a V8 you need the cast impeller that has the tall vanes on the impeller.

[John V.]

No difference in early pumps for the '63 389 and 326. The 4 bolt Water Pump p/n 540069 serviced all Pontiac V8s and the '63 Tempest 336 CID V8 (or 326 if you prefer). I believe this pump was first used for the '61 Model Year.

I don't know the pre-'61 p/n, but 540069 was the Service Replacement for ALL '55-63 4 bolt Pontiac V8 Pump Applications (the '61-'62 Buick V8 that was offered for the Tempest doesn't count). I also do not know if this is the p/n that would appear on the casting or if it is the Service p/n assigned to a pump & gasket package for instance and not the p/n on the pump body itself.

Either way, a 4 bolt pump that works for a '63 389 is correct for you.

For the later model 8 & 11 bolt pumps, most guys have better experiences with the O.E. type cast impellers rather than the aftermarket type stamped steel impellers.

Take Keith's advice, just make sure the cast impeller vanes are the tall ones as seen in his picture.

[mechanickeith]

Thanks John!!! Just trying to make sure correct info is out there!! Anything it takes to keep our ropeshaft cars on the road!!!!

Keith

[63Banshee]

check it out

[mechanickeith]

Cool!!! Have never seen one before. Is this the definition of rare???

[63Banshee]

Not sure how rare, but rare enough considering it was built for an engine application produced for a few months.

[mechanickeith]

Photo updates, my kodak gallery got deleted, so I'm posting them again.

[63Banshee]

http://cgi.ebay.com/ebaymotors/1963-...-/380177644443

Anyone need/want one? Double check the application. I don't remember the part number off the top of my head.

[Rad Randy]

Originally Posted by mechanickeith

Photo updates, my kodak gallery got deleted, so I'm posting them again.

Thanks for reposting the pics here. I went to the previous kodak links and they were deleted like you said. Good info.
Randy

[pontiaclady]

This is a little off 4 cyl subject, but regarding waterpumps... I just had the 421 rebuilt on my 66 GP and seems to be running hot. Not overheating - but when I open the hood it puts off a WHOLE lot more heat than before. Sheet metal really hot, even battery feels hot. Having trouble starting once hot, cranks, but not catching - have to let it cool before it will start. With engine rebuild, they put on a new waterpump from Napa. I wonder if it could have impeller issue with the waterpump. Any advice or information is appreciated. Thanks in advance.

[mechanickeith]

There is extensive coverage in the heating/cooling tech forum. Need to look at the cast impeller thread. Ensure the radiator is ok, fan shroud & clutch, thermostat. Check the engine temp with a known good mechanical gage. Water pump impeller & divider plate set up correctly. Lots of little issues can add up real quick & make big problems.

[John in Minnesota]

Could be timing.

[mechanickeith]

True, could be a timing issue.

[GaryK]

The one on the left I just pulled out of my 4 cyl. This could be the reason the motor ran hot when I went over 70 MPH (3200RPMs). The one on the right I had rebult which looks to be correct.

[c5farmer]

Start with the easy stuff first....Check the thermostat to make sure it is opening all the way. I have had a couple rebuilt engines start and run hot due to the thermostat sticking. Didn't change the thermostat out during the rebuild and it may have dried out from sitting in the air. If it is a new thermostat make sure all the air is purged from the system.
Next make sure the radiator cap will hold 15 lbs. (or rated pressure).

It can be a number of things, keep searching and eliminating possible causes until you find it. A new rebuild should not get hot to the point that it will not restart.

[mechanickeith]

Gary,, Have you tried the new pump yet at road speed?? I went back & reread the entire thread to refresh my memory. I found that my Kodak pictures are back!! Interesting. I have 1 pump with the spiral cast impeller. Needs rebuilt. I have only ran the more common style with the 6 short vanes so have no first hand experience with the other kind. Let us know how it does with the new pump.!!

[GaryK]

Jerry, I have a brand new 195 degree stat in and the cap is a 15lb new stant as well. I am pretty sure I most of the air out of the system. The radiator was checked professionally and was told it was in good condition. I thought it had more to do with running higher RPMS. I am looking at a new 3 row aluminum radiator on eBay.

Keith, I was following your post and the article you wrote for the Ropeshaft Reader. From this info, I thought this spiral cast impeller was wrong since it was not mentioned anywhere. Is this a correct water pump for the 4 cyl? I will have it rebuilt if its the right one. I am still in the process of putting the new motor together and will let you know how the new pump works in about a month.

Gary

[mechanickeith]

Gary,, The pump I have has the correct dimensions on the impeller for a 4 cyl motor. I have never ran one so dont know if it works ok or not. I have only ran the style of pump you just had rebuilt. After I was rearended I had a radiator recored by a specialty shop here in town. It was hand built to fit the stock tanks. I used to run 210-230 in town in 5 o'clock traffic. No other changes except for the radiator after the accident. New 3 row copper core radiator temps sit at 185 with a 180 stat!! Old radiator was a 4 row recore done here in town. Never could get it to run cool till I put in the new 3 row. Cost for having the 3 row built, $269 bucks with a guaranty that it would run cool or it was free!!!

PS!!! before installing a new stat, drill a 1/8" hole in the stat base so air can purge from the system. No need to run it till the stat opens to top off the system. Fill it & go!