Author Topic: Water Pump Bypass fitting..  (Read 2785 times)

dutch

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Water Pump Bypass fitting..
« on: January 12, 2017, 06:21:43 PM »
Another water pump question..
My '68 Z2/8 has a water pump that appears to have been changed at some point. If I recall, the casting number when I checked matches what Jerry's book said should be correct for the timeframe the motor was built in, but I couldn't find a stamp anywhere where it was suggested it would be.. 
There is a lot of paint on it, possibly if the stamping is there and light and I could have covered it with my overzealous paint skills!
Anyway - the pump has a plug in the top where a bypass fitting should be and from what I've read the bypass hose deal doesn't do much if anything to aid cooling - but I'd still like to make it appear somewhat more 'factory correct'- but I'm not sure how I can get the plug out without possibly ruining the pump itself.
I read where some pumps that aren't originals have the wrong diameter holes as well and this makes necessary some form of sleeve or adapter.
I did try a large box end and with some assistance from a hammer, managed to produce no apparent movement in the plug so I am assuming these after decades are going to be near impossible to remove without liberal use of heat and/or Liquid Wrench etc..
Suggestions as to the best way to get the plug in it now out - and if in fact it might be an original, can or will heat easily reduce the internals to crap easily?
Assuming I manage it (all things come apart in some way or another - eh?) -  if the hole diameter is in fact proven to be wrong for any such fitting, what would be the best and least apparent way to adapt it?

Thanks - Randy 

Petes L48

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Re: Water Pump Bypass fitting..
« Reply #1 on: January 12, 2017, 06:45:10 PM »
Here's and old thread discussing the 1/2 inch NPT threaded hole (passenger car) versus 3/4 inch hole (truck) pumps.

http://www.camaros.org/forum/index.php?topic=6056.msg39552#msg39552

Sounds like the pump is still mounted.  If not, I've had decent luck immersing rusty cast iron parts in Evaporust for a few days to free-up stuck pieces.  I've even used this when I had several items with nooks and crannies that needed all the rust removed.  If still on the car, can you get to it with an impact wrench after you soak it with WD40 or something? 
http://antique-engines.com/electrol.asp

   

z28z11

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Re: Water Pump Bypass fitting..
« Reply #2 on: January 15, 2017, 07:02:20 PM »
Suggestions as to the best way to get the plug in it now out - and if in fact it might be an original, can or will heat easily reduce the internals to crap easily?
Assuming I manage it (all things come apart in some way or another - eh?) -  if the hole diameter is in fact proven to be wrong for any such fitting, what would be the best and least apparent way to adapt it?
Thanks - Randy 

1) Get either Kroil or PB Blaster added to your rust releasing inventory. Not trying to promote them, but both work extremely well - just soak the threads above the connection and let it sit for a while, soak again, and I'd bet it will back off without using heat at all. I've used both on stubborn pipe threads on master cylinders, and the stuff will soak completely through the casting from one side to the other through the pores of the casting itself. Works really good on exhaust manifold fittings, too.

2) Best way to reduce the hole from 3/4 to 1/2 is use a bushing - I'd use a black iron reducing bushing, tighten it until it's seated, cut it off flush and have it welded in if you aren't equipped to weld it yourself. Smooth it, sandblast to pick up the finish, and there you go. Look at some of the "reconditioned" pumps being sold, and a lot of them show suggestions of doing just this (due to the availability of 3/4 NPT castings compared to the scarcity of 1/2 originals).

Just my 2 centavos -

Regards,
Steve
1968 Z28 M21/U17 BRG/W
1969 Z28 X77/M20/VE3 LeMans/W
1969 L78 X66/N66 Cortez/BVT
1969 Z11 L48/M35/C60/C06  1949 3100 5wd 235/6

dutch

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Re: Water Pump Bypass fitting..
« Reply #3 on: January 16, 2017, 11:09:17 AM »
Thanks for the replies - the car is stored for the Winter - but this is on my 'to do' list when and if it ever stops snowing and we get to see some grass (maybe early to mid May the way it looks now) but I will attempt the removal and go from there - and yes it is still and will be one the car when I do attempt it..
Anyone have an idea of who sells the best reproduction bypass fitting for an early 1968 model 302 engine.. I think there were two styles - one for 1967 models more of a hexagon shape body if I recall, and one for 1968's more squared off - but like many other bits on my car there was probably a carryover deal and maybe mine again falls into the situation where some things deemed '67 model year ended up on some of the earlier '68 model cars..
Block was assembly stamped in late Dec '67 and cast in early Dec so would it be possible that one or the other could or should have been found on it?
Thanks again - Randy 

z28z11

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Re: Water Pump Bypass fitting..
« Reply #4 on: January 17, 2017, 03:28:28 AM »
Try this one from Heartbeat. Looks pretty good -

Hex style:
http://www.rickscamaros.com/camaro-water-pump-bypass-fitting-90-elbow-z28-1967-1968.html

Square style:
http://www.heartbeatcitycamaro.com/store/product/13601/Camaro-Water-pump-bypass-fitting-302-1968/

Parts Place has the square one in silver zinc for a few dollars less -

Regards,
Steve
1968 Z28 M21/U17 BRG/W
1969 Z28 X77/M20/VE3 LeMans/W
1969 L78 X66/N66 Cortez/BVT
1969 Z11 L48/M35/C60/C06  1949 3100 5wd 235/6

dutch

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Re: Water Pump Bypass fitting..
« Reply #5 on: January 17, 2017, 08:09:39 AM »
Thanks for the links!   
I still haven't found out if there was any 'hold over' into the 1968 models from the '67 parts bins for 302 models that might have seen some of the earlier style fittings used on production engines for the 1968 year models.
Distributors were batch built and mine was and is one example where this happened - but have the bypass fittings ever shown to have the same possible model year carry over or crossover issues?
Any 1968Z 2/8 owners - especially 1968 model car owners with 1967 302 engine build or casting dates see any of the 1967 style fittings on their engines - or was this a clean break for 1968 production and the styles changed appropriate to the model year? 
Randy

x66 714

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Re: Water Pump Bypass fitting..
« Reply #6 on: January 17, 2017, 11:36:10 AM »
I thought there was some discussion about bypass fittings on 1968 Z/28? As I recall hex was used by all through 1968 & square was the replacement. Anybody have some input to that please? Joe
See America's First, Chevrolet

1968 Z/28 Corvette Bronze. Black Hounds Tooth. 02E Los Angeles born 3/13/1968 pnt OO. Purchased March 1976
1969 SS396 Yellow/Yellow 08E Norwood born 8/28/1969 pnt 76E. Purchased April 1981

1968RSZ28

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Re: Water Pump Bypass fitting..
« Reply #7 on: January 17, 2017, 04:41:52 PM »
I thought there was some discussion about bypass fittings on 1968 Z/28? As I recall hex was used by all through 1968 & square was the replacement. Anybody have some input to that please? Joe

Hexagonal is correct. More info here...  http://www.camaros.org/forum/index.php?topic=6942.msg45360#msg45360

Paul