Author Topic: GM Big Block Aluminum Water Pump  (Read 11205 times)

twol78s

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GM Big Block Aluminum Water Pump
« on: February 09, 2015, 02:20:28 AM »
Anyone here familiar with GM big block aluminum water pumps?
When I got my '67 SS/RS 396 L78 Camaro many years ago, it had this aluminum water pump on it.
I'm quite positive that this is the factory water pump, probably being a replacement put on the car to replace the original cast-iron water pump, probably sometime in the 1970's.
The part or casting number is 3875[89]28.  The [89] indicates that I can't tell if that digit is an 8 or a 9.  There also appears to be some other code reading 5421 stamped below the casting/part number.
I've searched around to see if I could find information about this water pump, but haven't been successful.
Was this a parts-counter-only water pump, or was it installed from the factory on some GM big-block equipped car?
The water pump works fine, and I at this point I'm not inclined to replace it with a correct cast-iron water pump, but would just like to know more about it.
Thanks in advance,

-Rick


cook_dw

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Re: GM Big Block Aluminum Water Pump
« Reply #1 on: February 09, 2015, 12:56:08 PM »
I have the same pump on my 67.  (3975928)  From what I could gather its a L88 or heavy duty pump sold over the counter that they offered up through the 90's.  If you look on yours you should see the date cast into it.  Here is mine for reference of the date.  If yours does not have a date then it is probably one of the early ones from the 70's.  Maybe someone else will have better info but that is all I know of them.



twol78s

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Re: GM Big Block Aluminum Water Pump
« Reply #2 on: February 09, 2015, 03:04:28 PM »
Interesting that your pump also has the '5421' stamping below the part/casting number.   In my original post, I omitted the word "not" in the sentence "I'm quite positive that this is the factory..." -- I should have said "I'm quite positive that this is NOT the factory...".   I figured that it was an over-the-counter part, but it'd sure be interesting to find out what purpose it served. I would think that it wouldn't necessarily be as durable as a cast-iron unit.  Clearly, it has to be somewhat lighter than the cast-iron pump, which is an advantage in any kind of racing.   

I was surprised to learn that the ZL-1 engines used a black-painted cast-iron water pump rather than this nice aluminum part - after all, the point of the ZL-1 was to be lightweight.   I've seen some very correct L-88 Corvettes, and they also had cast-iron water pumps, and all of the COPO Camaros, Yenkos and such that I've seen also had cast-iron water pumps.    So, I suspect that this pump was not put on any vehicle from the Chevy factory, but I'd love to have my suspicion proven wrong.

Thanks, Darrell, for the reply, and the clarification on the part/casting number.  Wonder what that "5421" designates?   I'll have to see if I can see the casting date on mine, but it's on the car, and it's a little difficult to see given its location.   

Be well, everyone,
-Rick

william

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Re: GM Big Block Aluminum Water Pump
« Reply #3 on: February 09, 2015, 06:34:23 PM »
Well not entirely true. When Bill Porterfield acquired ZL1 #1 many years ago he was provided photos of the car being prepped at Dick Harrell's shop. One of the engine photos shows an aluminum water pump. At least #1 and possibly the #2 ZL1 had pilot engines [V prefix] built at Flint. His contacts at Chevy engineering stated the aluminum pump later failed durability testing and was not released for production. The remainder of ZL1 Camaro production had iron pumps painted black as stated.
Learning more and more about less and less...

L78 steve

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Re: GM Big Block Aluminum Water Pump
« Reply #4 on: February 10, 2015, 04:57:43 PM »
I'd  Like to see pics. of your 67 SS/RS.
69 Z/28 Dover White. SOLD
67 SS/RS Mt. Green 1W,2LGSR,3SL,4K,5BY,07C. SOLD
70 Nova L78 Blk. Cherry,Sandalwood,M21,02B

twol78s

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Re: GM Big Block Aluminum Water Pump
« Reply #5 on: February 10, 2015, 08:07:10 PM »
Sadly, I don't have any decent pix of the Camaro...I'm one of those kind of folks that it just doesn't occur to me to take pix.

Here is an old photo of the car, taken many years ago with an early digital camera, so the quality isn't that great.
I promise that once the weather gets better, I will bring the car out and take some nice photos of it and post them here.

The car is a LOS-built, 67 SS/RS 4K L78 4-speed car.   It was delivered to Herb Hallman Chevrolet in Reno.  Build date is 5/22/67 (UOIT is dated 5/17/67).  It ended up in Salem, Oregon and spent a good part of its life racing, both on the drag strip as well as street racing.  Original owner appears to have passed away, but I have been in touch with the third and fourth owners.  They both had a lot of interesting street-racing stories to tell.

I bought the car in 1980, and it had just over 36K miles on it. It was in pretty decent condition, though the paint was tired, the car needed brakes and a clutch, the driver's seat was tattered, and the vinyl top was very checked from sun exposure. 

The K19 smog system was long-gone, as were the exhaust manifolds, which were replaced with headers.   

It has the numbers matching engine and rear-end, but the trans must have grenaded somewhere early in the car's life, and was replaced.  The car is Butternut Yellow with black vinyl roof, deluxe interior, AM radio w/rear speaker, and rear window defogger.

The car was repainted (full strip and repaint) in the early '80's with the correct paint, the engine was rebuilt also in the early '80's, to stock state with extreme care taken to preserve the original engine pad code (MR) and partial VIN, and the front seats reupholstered (With original GM replacement seat covers, which were still available) and the carpet replaced, along with a new vinyl roof.   

I replaced the  original Muncie shifter with a Hurst Competition Plus (I still have the Muncie shifter though), because the Muncie was just plain horrible.

I found the UOIT in the car when going through the interior, which matches the cowl tag body number, and also matches one-for-one option wise with the cowl tag.  I don't have the POP, sadly.   

The car  isn't perfect given that the smog system is gone, and it has a replacement 3910 carb dated from '75 (I found the previous owner that replaced the 3911 because it "never ran quite right"), and a replacement (but proper part-number) distributor.    The front suspension has been rebuilt (using Polygraphite parts).  The original (non-power front disc brake) master cylinder was rebuilt by White Post Restoration a few years back.  I'm thinking about having the steering box gone through, as the steering is getting a little sloppy.  The paint is still pretty nice, but there are a few little rock chips on the front valence and header panel.

I have an MSD ignition system on it (but have the original correct coil), as it really helps running on today's fuel, and run it with a mix of Sunoco 110 octane leaded racking fuel and 92 octane non-ethanol premium pump gas. 

The car is a driver.  I don't drive it daily, but take it to cruise ins and local car shows, and will take it on nice scenic drives in nice weather.  The car has never seen rain since I've owned it. It is kept in a heated/air-conditioned garage.  I've put about 3000 miles on it over the years.   I absolutely love driving it.  It sounds wonderful, has that amazing big-block torque, but revs almost like a small block, and will annihilate the rear tires at will.  I've told my wife when I die that she is to put me inside it with one hand on the shifter, the other on the wheel, drain all the fluids, and dig a big hole on our property, drop the car and me in, and cover it up.  So...don't ask if it's for sale.   

-Rick
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'67 SS/RS 4K 4-speed
'69 Z/28
'69 Nova SS L78 4-speed

cook_dw

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Re: GM Big Block Aluminum Water Pump
« Reply #6 on: February 10, 2015, 08:20:10 PM »
Pretty car.

twol78s

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Re: GM Big Block Aluminum Water Pump
« Reply #7 on: February 11, 2015, 03:07:17 PM »
Thanks, Darrell.    Love your '68 SS L78 -- unrestored originals are the bees knees!

-Rick

69Z28-RS

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Re: GM Big Block Aluminum Water Pump
« Reply #8 on: February 11, 2015, 03:34:52 PM »
.....
  I've told my wife when I die that she is to put me inside it with one hand on the shifter, the other on the wheel, drain all the fluids, and dig a big hole on our property, drop the car and me in, and cover it up.  So...don't ask if it's for sale.   

-Rick
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'67 SS/RS 4K 4-speed
'69 Z/28
'69 Nova SS L78 4-speed

that's a beautiful '67 Camaro... I really like it .. same color as the FIRST new '67 Camaro I recall seeing when a friend's parents bought him a butternut yellow/black vinyl top '67 SS350... :)  (I was SO very jealous!).. :)

so what about the '69 Nova... :)   is it for sale? :)
09C 69Z28-RS, 72 B 720 cowl console rosewood tint
69 Corvette, '60 Corvette, '72 Corvette
90 ZR1 red/red #246, 90 ZR1 white/gray #2466
72 El Camino, '55-'56-'57 Nomads, '55-'57 B/A Sedan

twol78s

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Re: GM Big Block Aluminum Water Pump
« Reply #9 on: February 11, 2015, 05:46:13 PM »
Thank you for the compliments on the '67 Camaro.

The '69 Nova SS is a survivor.  Very original car, with the only modification being a vintage Sun tach strapped to the steering column, and a replaced driver-side door.  69K miles.  Bought new locally and stayed local for its entire life.  At this point, it looks like I'm the 4th owner.  I've owned it since 1997.

All numbers matching drivetrain.  Have a couple copies of the build sheet that came with the car.  No POP or other documentation. 

The Nova is Frost Green with dark green vinyl top (not my favorite color combination). It has Black standard bench seating, rubber floor covering (no carpet), AM radio, power front disc brakes, and 4-speed with 3.55:1 Posi.  The car has the "SS" 5-spoke steel wheels. 

The JH code L78 has been rebuilt to factory specs.  Front end has been rebuilt with Polygraphite components, and the subframe detailed. 

Car has original paint, which is pretty tired.  Body is straight with only light surface rust.  The driver's side door appears to have been replaced at one point, but other than that, the sheetmetal is all original, as is all but the driver's door glass.

The car was clearly ordered as a stripper for racing.  The car had a very strong street racing history in Molalla, OR, and was known as king of the street for many years.  The smog system is long-gone, but it still retains the original exhaust manifolds with plugs in the AIR ports. 

My intention, over time, is to restore the car to original factory condition.  Even though I don't love this color, it will be stripped and repainted the original color, with the vinyl top replaced.  The front bench seat will be recovered and have new foam put in, as it is pretty broken down on the driver's side.  If I can find a correct smog system (if anywhere, from Jerry M.), it will be installed.  The undercarriage will be cleaned up.    Once it is done, it will be a driver.  My cars are all drivers, not show cars.  I'll take it to cruise-ins and local car shows (no big-time shows, just smaller ones), and take it on drives on nice days.   I may take it to the street drags just to see what it'll run in the quarter mile with street tires.

Clearly, with my plans afoot, the car isn't for sale.  While I don't have the same attachment to this car that I have with the '67 L78 Camaro, it is a "Keeper".

As I mentioned in the original posting here, I'm not big on taking pictures, so I don't have any photos of this one to post.  Maybe this summer I'll get some pix and post them on one of the Nova boards.

-Rick
---
'67 Camaro SS/RS LOS 4K(MR), 4-speed, Deluxe Interior, Console/Gauges, Butternut Yellow, 39K Miles
'69 Camaro Z/28, Deluxe Interior, Fold Down Rear Seat, Vigilite, Lemans Blue, 69K Miles 2nd owner
'69 Nova SS 396 L78, 4-speed, Frost Green, 69K Miles


L78 steve

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Re: GM Big Block Aluminum Water Pump
« Reply #10 on: February 11, 2015, 05:53:51 PM »
Nice! Thank you for taking the time to tell us about it. What is the axle code?
69 Z/28 Dover White. SOLD
67 SS/RS Mt. Green 1W,2LGSR,3SL,4K,5BY,07C. SOLD
70 Nova L78 Blk. Cherry,Sandalwood,M21,02B

69Z28-RS

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Re: GM Big Block Aluminum Water Pump
« Reply #11 on: February 11, 2015, 06:15:09 PM »
L78 Novas have been 'King of the street' in many locales.. :)   I remember one in the Mississippi Gulf Coast area when I was in the USAF there.  There were many $$$ spent on Hemis, Z28's, etc..  trying to beat that car!!  (not sure that any ever did).. :)

Your Nova is exactly the kind of car which appeals to me (based on your description).. I'd preserve it, drive it, but keep it as original as possible, but not restore it.. just do the things it needs and enjoy it and allow others to do the same!
09C 69Z28-RS, 72 B 720 cowl console rosewood tint
69 Corvette, '60 Corvette, '72 Corvette
90 ZR1 red/red #246, 90 ZR1 white/gray #2466
72 El Camino, '55-'56-'57 Nomads, '55-'57 B/A Sedan

twol78s

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Re: GM Big Block Aluminum Water Pump
« Reply #12 on: February 11, 2015, 11:06:40 PM »
We're getting a little off-topic here, so this will be my last post relating to the Nova here.

The Axle Code is BT 0708 G.  BT is 3.55:1 Posi.

The paint is not salvageable, nor is the front seat.  These will be redone.  Cosmetic stuff, and a lot of cleaning will be taken care of (e.g., the "SS" wheels will be cleaned up and re-painted), but everything else possible will be left alone.    I am not sure if the rubber mat floor covering will be able to be saved, it is pretty bad in the driver side footwell.  If I can find a good reproduction, it'll be replaced, else, I may end up putting noise deadening and carpet in it.  It is VERY noisy as-is -- it's amazing how much carpet quiets things down. 

The Fisher Body sheet shows:

Sequence 257
Date 07 11
Trim 731
Lwr 59
Top Upr S
PP 4

A01 Tinted Glass
A02 Tinted Upper Windshield
B80 Roof Drip Moulding
B84 Body Side Moulding
B90 Upper Door Moulding
CRD ???
C08 Vinyl Roof
L78 Spec Hi-Perf
M20 Muncie  4-Speed Trans
N10 Dual Exhaust
U80 Rear Speaker

Box 13 under the "COPO-F & SO" heading has something illegible in it that ends in '5', but can't make out the rest.

L78 steve

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Re: GM Big Block Aluminum Water Pump
« Reply #13 on: February 12, 2015, 02:51:18 PM »
What is the axle code on the Camaro.
69 Z/28 Dover White. SOLD
67 SS/RS Mt. Green 1W,2LGSR,3SL,4K,5BY,07C. SOLD
70 Nova L78 Blk. Cherry,Sandalwood,M21,02B

twol78s

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Re: GM Big Block Aluminum Water Pump
« Reply #14 on: February 12, 2015, 03:42:57 PM »
Oh, sorry.  The '67 Camaro has a PF axle code, 3.31:1 Posi, though before I got it the carrier and gears had been swapped out for 3.73:1 Posi with GM service parts.  The original carrier & gears were in a box in the trunk, though.  I'm leaving the 3.73's in it, though, as it's about acceleration, not top speed.

-Rick

 

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