C2:67 A well used water pump and hose

[Gerard F.]

Not for sale, just for information. First time off my 67 base engine, 40 years old and I guess it was ready for a change. Got the original radiator and block flushed, changed the pump and lower hose (all correct), and now I can't get over 165 degrees. (But I haven't really hit a hot day yet).

From the looks of the spring in the hose, I'd say I have another 10 years on the radiator (but I could be wrong).

Here's a closeup of the pump:

The date code is F227 and casting on the other side is GM 15 over 3782608. I assume the 15 after GM is the casting mold, the one I put on was GM 14 and I have another 608 which is GM 16. I understand that an F227 on a 0626 engine is not unusual, but it still amazes me, just 4 days difference.

Here's a closeup of the markings on the lower hose:

Now someone is going to tell me that this is service replacement, but I think it is original to the car. The repro I have on now is certainly different in the markings. Can't figure out what appears to be "TG" after the 3887155. Does anyone know what this means?

Let's get back to the business of the hobby. These cars are just wonderful to work on, even for an apprentice like myself. Don't think I'm gonna reuse the lower hose or the clamps, but the new clamps I put on have the same date code.
And I'm gonna redo the water pump myself.

Having fun,

Jerry Fuccillo
#42179

[Joe L.]

Re: C2:67 A well used water pump and hose

Jerry------

I think that the pump is very likely original. Everything "lines up". The date is very consistent. Keep in mind that the pumps were cast at Saginaw and machines/assembled at Flint. So, the "flow" was similar for blocks and heads, also cast at Saginaw and machined/assembled at Flint. Of course, the dates could also vary by quite a lot. That's because stock was not "rotated" (as Phil Hawkins used to say, they were in the auto business, NOT the grocery business).

You'll also note the "4 hole" pulley hub. Primarily, this was a PRODUCTION-only configuration. SERVICE pumps, including GM SERVICE pumps after the early 70's, were "8 holers". Also, most rebuilders convert the pumps to "8 hole" hubs so that they will work for more applications.

The longevity of your pump is very unusual. The 55-70 pumps with 5/8" shaft and small bearing were not noted for longevity. Usually, 50,000 miles is about it. The later 71+ pumps were MUCH improved. The large bearing and 3/4" shaft dramatically improved their durability.

I believe that the "TG" on the hose is a broadcast code used, primarily, at the assmbly plant to help line workers quickly ID the right hose for a car. However, since the code is specified on the specs for the part, it's usually on the SERVICE hoses, as well.

[Barbara S.]

Re: C2:67 A well used water pump and hose

Jerry: I can diagnose what happened to your water pump: this happens when you enjoy your car for 40 years. Keep it up!

Tony

[Nick Culkowski]

Re: C2:67 A well used water pump and hose

Jerry,

Could you please post a photo of the back side of your water pump?

I'm interested in the configuration of the back plate, especially the edge, sealing material and method, and its fasteners.

Thanks, and keep having fun.

Nick

[Gerard F.]

Photos of Water pump back

Nick,
In the below photo, the block gaskets are in place. They are very thin black gaskets. The water pump was repainted once while on the car.

Top view:

Can't see the back plate gasket, must be very thin also.

Bolts:

All L head markings.

Regards,

Jerry Fuccillo
#42179

[Joe L.]

Re: Photos of Water pump back

Jerry-----

The pump is clearly an original pump. All the screws are of the type and headmarking commonly seen for the period. The gaskets are the correct color material AND the left side gasket is the correct, PRODUCTION configuration (no lower hole and, apparently die cut that way, not trimmed; this configuration gasket was never available in SERVICE).

Also, the paint pattern on the rear plate is exactly how most original pumps received paint. A rather large, lower area of bare steel is usually seen since the pump was painted on the engine and very little paint got to that area.

Another point of originality is the end of the shaft. Note that it has a somewhat rough, "chopped off" appearance. This is how most of the original Delco bearing/shaft assemblies appeared. I don't know why.

One thing is quite interesting to me. The rear plate used for 1961-82 Corvette pumps (as well as most other small block pumps of that period) was of GM #3782610. However, this plate had at least one change over the period of its use. That change involved the addition of a linear stamping between the bolt holes. The ridge thus formed on the inner gasket surface of the plate helped to improve gasket sealing. Once-upon-a-time, as an experiment, I pressure tested pumps using plates with the stamping and without. The pumps without the between-the-holes stamping would barely hold 15 PSI. With the stamping, they would consistently hold 15+ PSI.

Now we know that the stamping had not been added by 1967. So, I would suppose that pumps in the 61-67 period lack the stamping. Just when it began after that, I'm not sure.

When you remove the rear plate, I think that you will find a black gasket that is quite thin---not quite as thin as the to-block gaskets but pretty close. Most rebuilders use a much thicker gasket (which sometimes results in interference between the backing plate and the timing cover for "short leg" waterpump applications).

One other thing that you could check for me is this: check end of the "snout" and, especially, the inner circumference of the "snout's" bearing orifice. Is the end of the snout machined flat or is it as-cast? If it's machined flat, is there a significant machined chamfer on the "snout's" INNER circumference?

[Nick Culkowski]

Re: Photos of Water pump back

Jerry,

Thanks for the great photos. Hopefully between them and Joe's detailed description some common issues can be resolved.

Joe, could you please describe what we should expect to see in original 67 BB water pump back plates in terms of finish, configuration, sealant method and fasteners?

Thanks, Nick

[Gerard F.]

Is this the "snout"

Joe,

If so, there is no machining, just rough cast. Looks like a casting mark inside. Also have an F137 the same way.

Does this make you hungry?


Best regards,

Jerry Fuccillo
#42179

[Joe L.]

Re: Is this the "snout"

Jerry-----

The "snout" I was referring to is actually the portion of the casting which contains the orifice for the bearing/shaft assembly.

Pictured below is the "snout" of another small block pump (this one is actually from a GM #3839175 casting but the "snouts" are pretty much the same on 55-70 Corvette waterpump castings (but not necessarily exactly the same on finished pumps).

You'll note that the one pictured has a "more-or-less" rough cast end which looks like it received machining on some portions of the face of the "snout". You will also notice that this one has a significant (but WAY off-center) chamfer machined on the inner circumference of the "snout's" orifice.

Does that second picture make me hungry? YOU BET IT DOES. It's been about 2 months now since I've had any lobsters or steamed clams and I'm long into "withdrawals". Seeing those lobsters and clams ABSOLUTELY MAKES MY MOUTH WATER AND I DON'T MEAN MAYBE. Especially, those clams. These were particularly succulent examples of the New England steamer clam. Notice the color of the shell and the PERFECT size! Also note the perfectly steamed condition with the within morsels just "peeking out". The beautiful light yellow color! I'm BADLY in need of a "fix". Fortunately, there is a place in Redwood City I can go and get both. Not quite as perfect as the ones in Essex and, certainly, not as large of a portion. Also, VERY expensive (particularly considering the portions it takes to satiate my appetite for these things). But, I can, at least, get some. As expensive as it is, it would be cheap at twice the price! Especially when I haven't feasted on any in 2 months!

[Joe L.]

Backing Plate

Jerry-----

Attached is a photo of a GM #3782610 backing plate AFTER the linear stampings between mounting holes began. These simple stampings greatly improve the sealing of the rear of the waterpump.

[Joe L.]

Re: Photos of Water pump back

Nick-----

I can do better than describe. Attached is a photo of an NOS GM PART #3876173 (CASTING #3856284) waterpump. This pump casting is dated "K 22 6" (November 22, 1966) so, if this one had ended up in PRODUCTION, it could have been used on a fairly early 1967 Corvette big block. By the way, the date has to be 1966 since, obviously, the pump could not have been manufactured in 1956 and the 3856284 casting was LONG out of production by 1976. Also, the GM PART #3876173 waterpump assembly was discontinued in October, 1969.

Note the configuration of the plate and the pan head, slotted screws. Also, the gasket is a light tan, cellulosic fiber which is fairly thin. I see no evidence of any sealer having been used. In other words, there is not the slightest indication of any "squeeze-out" at any place along the perimeter of the gasket.

There is an external tooth star washer under the head of each screw. The diameter of the washer is almost identical with the diameter of the screw head, which is 1/2".

The backing plate was GM #3878262 and the gasket was GM #3734991. Both are long-since GM-discontinued.

[Gerard F.]

Ooh! I won't be able to tell for sure

Until I take it apart. But the outside looks machined flat to me. I'll let you know for sure when I get to that project.

Here's a picture of the group, at the most memorable dinner I've ever had:


Essex 2007. You know the places, Joe.
I still remember the lecture on the lobster tamales.

Jerry Fuccillo
#42179

[Joe L.]

Re: Ooh! I won't be able to tell for sure

Jerry-----

I TOTALLY agree. It is right up there at the top of my list, too. Just absolutely wonderful in every possible respect.

The only other dinner that I can recall in my life that I enjoyed about as much was the dinner at the Sardine Factory in Monterey during the 2002 NCRS Convention.

And, believe me, I've been out to dinner a LOT of times in a LOT of places with a LOT of different people.

I consider myself TOTALLY blessed that I was able to partake in BOTH of those phenomenal dinner "happenings---Essex, MA in 2007 and Monterey, CA in 2002. In fact, as I reflect on it, I was the only person at both of those events, so I'm "doubly blessed".

[Wayne M.]

And here's the first generation BB backing plate

found on '65 L78's -- perfectly flat. This is on "284" pump cast E_5_5 (May 5th).

[John H.]

Re: Ooh! I won't be able to tell for sure

Joe -

Here's that wonderful dinner at the Sardine Factory - it was an evening to remember!