1964 365hp correct #

[Timothy B.]

Re: 1964 365hp correct #

Pictures of service pump #3839175 bought new by me. Dates on the pumps are L 13 7 and L 17 9, both have the later style rear cover with the emboss to help seal.

[Joe L.]

Re: 1964 365hp correct #

Pictures of service pump #3839175 bought new by me. Dates on the pumps are L 13 7 and L 17 9, both have the later style rear cover with the emboss to help seal.

Tim------


Very interesting, indeed. Given when you bought the pumps, I would expect that the years represent 1977 and 1979. Even if it were 1967 and 1969, either HIGHLY doubtful, it would still be well after the presumed end of production for this casting.

It's also interesting that both castings were made from pattern 13, even though they were cast 2 years apart. This may reflect the fact that, by the time these were likely cast, the SERVICE use was so low that a single pattern was sufficient. Or, it could mean that this was the only surviving 3839175 pattern and most others used for SERVICE pumps were the 3859326.

Note that the casting number digits are out-of-line. This is somewhat unusual and may tell us something about the "pedigree" of these castings, but I don't know what. Also, I am virtually certain that these were cast at Saginaw. Among other things, Tonawanda castings usually have the reinforcing ribs and a "T" casting mark, usually following the "GM".

There are a few other things that this pump may reveal. First, it may explain all the 3/4" by-pass versions of this reported as having been seen by Jack H. PRODUCTION use of this casting for Corvettes, under any circumstances, would have been quite small; SERVICE use could have been extensive and for many years since the casting was first used for 1964 and, apparently, was used to the late 70's, at least.

Second, since the 3839175 casting was used for SERVICE well after its possible use for Corvettes ended, it could very well be that it was used in PRODUCTION, with 1/2" NPT bypass fitting, for some Corvettes in the 1965-67 period. Apparently, the 3839175 was not phased out when the 3859326 was phased-in.

[Timothy B.]

Re: 1964 365hp correct #

Joe,

I can get some better pictures if there is something you want to look closer at.

Maybe this may help date these pumps, I remember the boxes being green lettering with (I think) white box. I remember thinking that the boxes look old. These pumps came from Lustine Chevrolet in Md. but probably from the GM local warehouse.

[Joe L.]

Re: 1964 365hp correct #

Joe,

I can get some better pictures if there is something you want to look closer at.

Maybe this may help date these pumps, I remember the boxes being green lettering with (I think) white box. I remember thinking that the boxes look old. These pumps came from Lustine Chevrolet in Md. but probably from the GM local warehouse.

Tim------


Those pictures were fine. The boxes and printing you describe were generally used from the mid-to-late 60's through the early 90's. Earlier boxes were all black and yellow; later were natural brown cardboard. Some mid-to-late 60's through early 90's were also natural brown cardboard.

[Timothy B.]

Re: 1964 365hp correct #

I am not trying to stir the pot, but from what I have seen what's the difference between the 175 casting and 326. I can't tell them apart, both have a thick boss where the larger bypass would be drilled..

The #175 service pumps I have are drilled for the small 3/8 bypass and have a instruction sheet to install the dowell supplied if external bypass is used. This instruction sheet is dated 1970 FWIW.. so this would mean these pumps are cast in the late 70's.

[Joe L.]

Re: 1964 365hp correct #

I am not trying to stir the pot, but from what I have seen what's the difference between the 175 casting and 326. I can't tell them apart, both have a thick boss where the larger bypass would be drilled..

The #175 service pumps I have are drilled for the small 3/8 bypass and have a instruction sheet to install the dowell supplied if external bypass is used. This instruction sheet is dated 1970 FWIW.. so this would mean these pumps are cast in the late 70's.

Tim-----


Yes, the SERVICE pumps were supplied with only a square head pipe plug to eliminate the external bypass if internal bypass was used and a 3/8" dowel to eliminate the internal bypass if external bypass was used. Also, the PART number you mentioned of the pumps you have shown, GM #3998206, would alone confirm that the dates on the pump represent 1977 and 1979. That part number was not released until about late 1971, so if the dates represented 1967 and 1969, then the castings would have had to have been "sitting around" for 2-5 years before manufacture of the finished pumps and, then, the finished pumps would have to have been sitting on a shelf for about 10 years for you to purchase them in 1981. This scenario is HIGHLY unlikely, to say the least.

Also, as I mentioned previously, even if the dates did represent 1967 and 1969, that would still be quite a while after the period in which we have presumed the 3839175 casting to have been phased out and would still mean that, theoretically, the 3839175 could have been used on some small block Corvettes with external bypass in the 65-67 period.

As far as the differences between the 3839175 and 3859326 castings, that's pretty much a mystery to me. Other than the casting number, I really don't see any external difference. I think it's possible that there were very slight internal differences, though. Whatever the differences were, they could not have been so important as to result in the complete replacement of the 3839175 patterns inasmuch as the 3839175 was still, apparently, being used as late as 1979 alternately with the 3859326 for SERVICE purposes.

It would be very interesting to learn something about the history of these two castings.

[Lynn H.]

Re: 1964 365hp correct #

I have a 175 pump that IS dated E4 3.

Is that '175 pump of yours a Saginaw or Tonawanda casting? Tonawanda dated their water pumps LONG before Saginaw started the process...

So there were actually some pumps dated well before some of the published information would indicate. Whether the pump I posses was actually factory installed on a Corvette or a truck is open for debate.

And that is a key part of the issue here... The NTL maintains the Judging Guide for his division of Corvette. Most want PROOF that this/that is true and rely highly on past experience with 'untouched' original cars. So, just because this/that exists or drawings say thus and such, typically doesn't cut it for 'proof'...

This is an area that I personally am very surprised that has not been cleared up with some type of list of accepted pumps (acknowledged by the NCRS) for the different applications, that it seems clear WERE used in Corvette production over the years.

It HAS been cleared up. The various Judging Guide books clearly define what cast numbers are believed to have been used where/when. What this conversation is about is an 'anomoly'...the '175 that appears as if it's the bridge between the '609 and '326. And, yes, officially it's not recognized...

One of the answers I get to this question is that it, IS NOT something that is judged (WP casting number). With that being the case it seems strange to me that it is not called out anywhere that points CANNOT be docked for this reason. I have been told by some people that an experienced judge may or may not deduct points for casting numbers, dates, etc, on water pumps.

The Judging Guide is just that...a GUIDE. It's intended to supplement the personal knowledge of those who judge. They have the right to set aside any/all information as well as to judge on things not published.

The only place we have a MANUAL these days is with the NCRS Corvette Judging Reference Manual published and maintained by the National Judging Chairman. Those rules are hard/fast...

When I posted on this a week or so ago, I mentioned I THOUGHT that my 175 pump dated E4 3, was a Tonawanda pump. I just ran across a photo of the pump and I believe the "S" signifies that this is a "Saginaw" casting. Hopefully someone will correct me on that if not, but if so I wanted to clarify my earlier statement of it being "Tonawanda". I tried to post photo, but it will not let me, since I have previously posted this photo.
Lynn

[Timothy B.]

Re: 1964 365hp correct #

Lynn,

All this talk about water pumps got me looking in the archives and it seems this has been talked about in detail years ago. I saw a pic of a 175 pump with S and it may have been yours, the S signifies Saginaw casting.

Interesting that my Saginaw castings do not have S. Is your pump drilled for 1/2" pipe threads?

[Joe L.]

Re: 1964 365hp correct #

Lynn,

All this talk about water pumps got me looking in the archives and it seems this has been talked about in detail years ago. I saw a pic of a 175 pump with S and it may have been yours, the S signifies Saginaw casting.

Interesting that my Saginaw castings do not have S. Is your pump drilled for 1/2" pipe threads?

Tim------


Not all Saginaw pumps have the "S" foundry mark. In fact, most that I've seen do not. Why, I don't know. The prints for the casting instruct that the foundry mark is supposed to be present.

The only 2 GM foundries that were pretty consistent about emplacing a foundry ID mark were Danville, IL ("D") and Tonawanda, NY ("T"). Saginaw Gray Iron and Defiance, OH usually did not emplace a foundry ID mark.

Tonawanda-cast small block pumps are usually easy to ID. They almost always have a "T" embossed on them and they usually have reinforcing ribs on the driver side of the casting.

[Jack H.]

Re: 1964 365hp correct #

I agree with Joe here...not all Saginaw water pump castings have a foundry source ID emboss. And, those that do are often located on the back (outside the lip of the rear plate) rather than in a conspicious front side location (like near the cast number) consistent with other Saginaw marks on different castings.

[William M.]

Re: 1964 365hp correct #

Lynn and Jack,
I have been selling rebuilt Corvette water pumps since 1978. Over the years I have had two "real" 3839175 undated water pumps with the 1/2" NPT bypass hole(see the picture of a undated "175" water pumps with a "GM 4"). These were very randomly used on some late 1963 and 1964 Corvettes with the solid lifter engine. The bypass boss is rounded on the front like a "609" boss but has the "meat" like a "326" boss. I personally have seen the "175" water pump on several unrestored 1964 375hp327 engines(I have a picture to support this if interested). As far as a 3839175 water pump with a 3/4" NPT bypass boss and a casting date, I have had many of these over the years. They were never used on a Corvette and also were service units. Lynn's "175" dated E43 is a May 4,1973 casting date.
Regards,
Bill Mock #93

[Jack H.]

Re: 1964 365hp correct #

Wow, a whole TWO units since 1978 and you're the MAN in this biz!!! Now I don't feel so bad about having only seen 20 or so of the '175 castings.

But, I can also say I've yet to see a '175 whose upper boss was totally rounded like the '609 pump. Here's my 'family' pix of 609, 175 and 326 pumps that I consider typical.

Note the '175 (center) does have an 'S' foundry identifier on the front side and the upper boss has a front side 'flat' like the '326 pump for pulley clearance. Taking a micrometer to the upper boss, the '175 casting had a VERY slender size difference (smaller) than the '326 casting.

There's not enough 'meat' on a '609 to drill/tap it for a 3/4" NPT bypass nipple. But, both the '175 and '326 castings have sufficient size to be bored to accept 3/8", 1/2" or 3/4" external bypass adaptors...

Whoops! I uploaded the pix but it doesn't show in the preview. This must mean I've provided it before and it's associated with another, prior post, that's in the archives. Let's see, maybe if I re-name it...

Nope, that doesn't get it... The website is pretty smart. It knows that pix, regardless of file name, has already been posted. Well, here's a link:

https://www.forums.ncrs.org/showthre...10428&uid=2347

[Joe L.]

Re: 1964 365hp correct #

Lynn and Jack,
I have been selling rebuilt Corvette water pumps since 1978. Over the years I have had two "real" 3839175 undated water pumps with the 1/2" NPT bypass hole(see the picture of a undated "175" water pumps with a "GM 4"). These were very randomly used on some late 1963 and 1964 Corvettes with the solid lifter engine. The bypass boss is rounded on the front like a "609" boss but has the "meat" like a "326" boss. I personally have seen the "175" water pump on several unrestored 1964 375hp327 engines(I have a picture to support this if interested). As far as a 3839175 water pump with a 3/4" NPT bypass boss and a casting date, I have had many of these over the years. They were never used on a Corvette and also were service units. Lynn's "175" dated E43 is a May 4,1973 casting date.
Regards,
Bill Mock #93

Bill------


I can't see it very well in the photo, but it appears like this '175' casting pump lacks the pulley relief on the forward side of the upper bypass boss. Does it actually lack the relief?

[Lynn H.]

Re: 1964 365hp correct #

Jack, I had the same problem with attempting to post another photo of the pump I have. I tried renaming (like you), and found I cannot outsmart the system. I think it would require another photo.

And Bill, thanks for the posting it bolsters what I had already started to believe from this and some of the other threads and postings on this issue. I had similar thought about the size of the "boss', and again your posting clears up these issues as far as I am concerned. I had reached the conclusion that the pump I have was 73 dated, and your post confirms this also.
Thanks!!!!!
Lynn

[John H.]

Re: 1964 365hp correct #

Whoops! I uploaded the pix but it doesn't show in the preview. This must mean I've provided it before and it's associated with another, prior post, that's in the archives. Let's see, maybe if I re-name it...

Nope, that doesn't get it... The website is pretty smart. It knows that pix, regardless of file name, has already been posted.

Jack -

The photo robot looks for both filename AND file size; I run into this frequently, and just rename and resize the image so I can post it again (or I upload it to my photo site and "call" it in full size). John Waggoner posted another workaround, but I can't find it.