#1  
Old 10-08-2020, 03:52 PM
Rincon Rincon is offline
Member
 
Join Date: Aug 2019
Posts: 37
Default Differences in ohc 6 water pumps?

Looking for a replacement water pump for my 1969 tempest. I see brand new ones for sale for 66-67's. So what is the differences?

  #2  
Old 10-08-2020, 04:05 PM
sprintbird sprintbird is offline
Senior Chief
 
Join Date: Feb 2002
Location: Anna, OH
Posts: 332
Default

Length of the shaft. I have a NOS 69 short pump available. The pulleys wont align if you try to use a 66 thru 68 long shaft pump.

  #3  
Old 10-08-2020, 05:10 PM
63 bomb's Avatar
63 bomb 63 bomb is offline
Member
 
Join Date: Mar 2020
Posts: 87
Default

I also have a couple reman '69 pumps laying around if anyone needs them.

  #4  
Old 10-08-2020, 07:07 PM
Jeff Hamlin's Avatar
Jeff Hamlin Jeff Hamlin is offline
Ultimate Warrior
 
Join Date: Jan 2000
Location: Beach side of Virginia
Posts: 8,565
Default WP 66-68 Vs 69

As mentioned the '69 WP has a short shaft unlike the long shaft on the '66-'68 pumps.
Also '69 no longer used a By-pass at the radiator hose neck, it was now incorporated into the casting.
Attached Thumbnails
Click image for larger version

Name:	WP 9.jpg
Views:	83
Size:	81.3 KB
ID:	551068   Click image for larger version

Name:	WP 69.jpg
Views:	83
Size:	48.7 KB
ID:	551069   Click image for larger version

Name:	1966-68 1.jpg
Views:	88
Size:	35.7 KB
ID:	551070   Click image for larger version

Name:	1966-68 x69.jpg
Views:	86
Size:	44.1 KB
ID:	551071  

__________________
When I die, I want to go peacefully like my grandfather did, in his sleep.
Not screaming like the passengers in his car.
The Following User Says Thank You to Jeff Hamlin For This Useful Post:
  #5  
Old 01-22-2021, 08:37 PM
sprinter 2 sprinter 2 is offline
Junior Member
 
Join Date: Apr 2008
Posts: 24
Default

Can the 66-68 be drilled out for a bypass and a shorter shaft installed or maybe cut off to make a 69? Looks like some of the 69 pumps have the 66-68 tap for the bypass and maybe someone made a 69.

  #6  
Old 01-22-2021, 09:16 PM
camerjeff's Avatar
camerjeff camerjeff is offline
Ultimate Warrior
 
Join Date: Dec 2004
Location: Belleville , Mi
Posts: 1,668
Default

Either can be done, I drilled a bypass hole in a 68 block once to use a 69 water pump. It would also have been possible to drill & tap a 69 water pump to use the external bypass hose of the 66-68 engines.

__________________
Jeff R
78 Catlina Safari, Soon to be Pontiac 400 powered
78 Sunbird Safari, Buick 231 V6 2004R
77 Astre Formula, 215 Buick V-8 T-5
73 Lemans Safari, 400 4bbl 4-speed
71 Catalina Enforcer, 455 4bbl
06 Mallet Solstice #024 LS2, Now with a Tremec 6060 6-speed!
09 Solstice Coupe, 2.4 Ecotech 5-speed manual
2012 F-150 Echo Boost (My local Ford Dealer SUX!!!)
2020 Dodge Charger Scat pack
  #7  
Old 01-22-2021, 09:41 PM
694.1 694.1 is offline
Ultimate Warrior
 
Join Date: Jul 2010
Location: SE WI
Posts: 1,092
Default

Funny that it took the engineers so long to figure that out...But maybe the bypass hose had advantages??

__________________
"At no time did we exceed 175 mph.
Dan Gurney's truthful response to his and Brock Yate's winning of the first ever Cannonball Baker Sea-to-Shining Sea...

Still have my 1st Firebird
7th Firebird
57 Starchief
  #8  
Old 01-24-2021, 08:31 AM
Jeff Hamlin's Avatar
Jeff Hamlin Jeff Hamlin is offline
Ultimate Warrior
 
Join Date: Jan 2000
Location: Beach side of Virginia
Posts: 8,565
Default

IMHO It would be far less effort the oe/correct rebuilt and/or rebuild it.

I just had two done, not cheap but they're not being pushed over the counter anymore.
Rebuild kits should still be available if you are able.

__________________
When I die, I want to go peacefully like my grandfather did, in his sleep.
Not screaming like the passengers in his car.
  #9  
Old 01-27-2021, 10:54 AM
camerjeff's Avatar
camerjeff camerjeff is offline
Ultimate Warrior
 
Join Date: Dec 2004
Location: Belleville , Mi
Posts: 1,668
Default

I was told it was a cost cutting move, Pontiac was being pressured to drop the OHC-6 and purchase Chevy I-6's. Chevy was making the case they could provide the chevy 6 at a price lower than Pontiac could build the OHC-6 and Chevy could still make a profit. Pontiac made many small changes to the 69 OHC6 besides the water pump.

The Water pump change eliminated many parts besides the bypass hose, there was the thermostat spacer, 2 hose clamps, and the fitting for the bypass hose on the water pump. The machining changes to block line consisted of drilling 1 more hole in the block for the internal bypass.

Besides the water pump they also

(1) replaced the cast aluminum rear upper timing belt cover with a stamped steel one. This also required the larger fiberglass upper cover to be remade with 2 bulges to screw the new cover onto.
(2) Replaced the upper timing belt cover mounting bracket that bolts to the front of the block and held the cover with 3 Mounting screws. With 2 Threaded stand offs that thread into the smae 2 holes in the block that the bracket did. And reduced the front upper cover mounting screw number from 3 to 2.

They also made some minor changes I forget at the moment. These changes required the modification of the following parts

Timing Belt front cover
Water Pump Pulleys
adding a flange on the timing cover to accept the thermostat without the spacer.
Replacement of the water pump gasket with a new design to use the internal bypass hole. It would also replace the 66-68 design as it would work with either water pump.

The changes eliminated about 10 parts from each engine made. The change in water pump shaft length was to prevent the installation of the incorrect water pump by mistake.

From a conversation with Fred Simmonds years ago.
The water

__________________
Jeff R
78 Catlina Safari, Soon to be Pontiac 400 powered
78 Sunbird Safari, Buick 231 V6 2004R
77 Astre Formula, 215 Buick V-8 T-5
73 Lemans Safari, 400 4bbl 4-speed
71 Catalina Enforcer, 455 4bbl
06 Mallet Solstice #024 LS2, Now with a Tremec 6060 6-speed!
09 Solstice Coupe, 2.4 Ecotech 5-speed manual
2012 F-150 Echo Boost (My local Ford Dealer SUX!!!)
2020 Dodge Charger Scat pack
  #10  
Old 01-27-2021, 07:09 PM
Jeff Hamlin's Avatar
Jeff Hamlin Jeff Hamlin is offline
Ultimate Warrior
 
Join Date: Jan 2000
Location: Beach side of Virginia
Posts: 8,565
Default

No dought the bean counters were part of the changes.

I'm unaware of any Cam housings not having the step for the Thermostat,
thus why the question of placement with the bypass seems to come up.
Compounded by the misguiding parts book image.
Attached Thumbnails
Click image for larger version

Name:	STAT SEAT CAM HOUSE 2.jpg
Views:	25
Size:	66.0 KB
ID:	559599   Click image for larger version

Name:	INCORRECT.jpg
Views:	23
Size:	36.6 KB
ID:	559600  

__________________
When I die, I want to go peacefully like my grandfather did, in his sleep.
Not screaming like the passengers in his car.
  #11  
Old 01-27-2021, 08:59 PM
694.1 694.1 is offline
Ultimate Warrior
 
Join Date: Jul 2010
Location: SE WI
Posts: 1,092
Default

Didn't know that the pump change was to prevent older pump installs. Good stuff.

__________________
"At no time did we exceed 175 mph.
Dan Gurney's truthful response to his and Brock Yate's winning of the first ever Cannonball Baker Sea-to-Shining Sea...

Still have my 1st Firebird
7th Firebird
57 Starchief
  #12  
Old 01-28-2021, 03:19 PM
camerjeff's Avatar
camerjeff camerjeff is offline
Ultimate Warrior
 
Join Date: Dec 2004
Location: Belleville , Mi
Posts: 1,668
Default

Jeff I used to have a few very early 66 Cam covers that did not have the step for the thermostat. But you are correct all 6 of the ones I currently have all have it.

__________________
Jeff R
78 Catlina Safari, Soon to be Pontiac 400 powered
78 Sunbird Safari, Buick 231 V6 2004R
77 Astre Formula, 215 Buick V-8 T-5
73 Lemans Safari, 400 4bbl 4-speed
71 Catalina Enforcer, 455 4bbl
06 Mallet Solstice #024 LS2, Now with a Tremec 6060 6-speed!
09 Solstice Coupe, 2.4 Ecotech 5-speed manual
2012 F-150 Echo Boost (My local Ford Dealer SUX!!!)
2020 Dodge Charger Scat pack
Reply

Thread Tools
Display Modes

Posting Rules
You may not post new threads
You may not post replies
You may not post attachments
You may not edit your posts

BB code is On
Smilies are On
[IMG] code is On
HTML code is Off

Forum Jump


All times are GMT -4. The time now is 12:49 PM.

 

About Us

The PY Online Forums is the largest online gathering of Pontiac enthusiasts anywhere in the world. Founded in 1991, it was also the first online forum for people to gather and talk about their Pontiacs. Since then, it has become the mecca of Pontiac technical data and knowledge that no other place can surpass.

 

Cold Case Radiators

Cold Case Radiators is a Max Performance company that produces high end aluminum performance radiators at a price point that won't break the bank. Polished and stamped tanks. 2 rows of 1" tubes. Lifetime Warranty.

GTOG8TA.com

GTOG8TA.com is a Max Performance company that manufacturers parts for the 04-06 GTO, 08-09 G8, and 93-02 Firebird/Trans Am platforms.

Copyright © 2017