What should be the clearance here?

[Gerard F.]

I know this is an aftermarket aluminum pulley on a 67 base engine car with a 608 water pump. I put it on with a Vintage Air System along with an aluminum crankshaft pulley.

But the clearance I'm talking about is between the aluminum pulley and the body of the 608 water pump at the outlet. Seems pretty close to me and I measure 1/32". Kinda scares me.

The question is, were the stock pulleys that close to the water pump body?

I'm planning on changing the water pump with a rebuilt one. On the rebuilt one which I have, I measure the distance between top of the fan mount to the bolt mount at 5 11/16". The overhaul manual says that distance should be 5 9/16".

If I left the new pump as is, it would increase the clearance to about 3/32", but would misalign the alternator pulley by about 1/8".

So what would you do, move the water pump fan flange back to spec, or live with a minor misalignment of the alternator pulley.

Let's get back to business, too much politics lately.

Having fun,

Jerry Fuccillo
#42179

[Joe L.]

Re: What should be the clearance here?

Jerry------

Stock small block waterpumps usually have minimal clearance between the face of the pump casting and the rear of the waterpump pulley in the area which you have pictured. I believe that '608' pumps actually have a slight relieved area cast into the pump body on either side for this very purpose. 1/32" sounds a little tight, but I don't think that it's out of range by very much. Plus, I think that you'll find that there will be a bit more clearance when a stock-type, stamped-steel pulley is used. This aluminum pulley appears to have a rear flange that is a bit thicker than stock type.

One thing that I always do with these: mount the pulley to the waterpump without the fan and fan clutch. Torque the bolts (or, nuts for 69+) to the specified torque. Then, rotate the pulley through several revolutions. If there is no interference with the pulley and the pump, there won't be any with the pump later in service . Even considering expansion of the metal when the engine comes to temp, I've never experienced later interference if it checked out with the test I described.

As far as the hub dimension goes, Chevrolet small blocks with short pumps used TWO different hub dimensions. In fact, once-upon-a-time there were actually available SERVICE pumps set to both dimensions (since the hubs used on these pumps are considered "non-adjustable"). The difference between the 2 hub dimensions was 1/8", exactly the difference between the spec you found and the pump you have.

I would use the pump which has the hub dimension that correctly aligns the alternator pulley, as long as the pulley and pump "pass the test" I described above.

[Rick S.]

Re: What should be the clearance here?

Jerry,
Off topic but looking at your stamp pad I see the assembly date of 062? and was wondering what is your date? Our cars are about 1000 apart for VIN's.

Regards,

Rick

[Gerard F.]

Re: What should be the clearance here?

Rick,

I have one of those infamous V0626HE engines. It amazes me that the block, waterpump and transmission dates are all June 22, 1967, just four days prior to engine assembly.


Jerry

[Rick S.]

Re: What should be the clearance here?

Interesting that the six for the month don't match on our blocks but the second six in yours matches my month six. They must have had more than one gang stamp when applying the date.

Rick

[Gerard F.]

Looks like you have that crazy 6 too

Rick,

It looks more like a lower case b.

As I understand, they had a box full of individual letters and numbers of different fonts, and picked them at random to make up the gang stamp. Looking at that crazy 6, it was probably the same individual one on yours and mine.

Looks like we might also have differences in the zeros.

Jerry

[Joe L.]

Re: What should be the clearance here?

Rick-----

I once had the opportunity to observe the engine stamping operation at Flint. Although this occurred in 1992, I don't think that the general procedure changed too much over the years. They did have an array of gang stamps, each pre-set with a different suffix code. The line person responsible for stamping the engine simply grabbed the correct gang stamp for the engine configuration and 'whacked' the pad. This prevented the need to change the characters in the gang stamp for each engine. Of course, the date had to be changed each day in all the stamps.

The engines were not built in "batches" of all a single configuration. Different engine configurations came down the line in a very "random" sort of fashion. So, this made the use of pre-set stamps for each configuration the most practical and efficient way to go. These gang holders and stamps were not very expensive, anyway, so I'm sure it was a lot less expensive to have multiple, pre-set gang stamps than it was to have a line person spend the time to change the suffix character(s) for each engine.

[Phil P.]

Re: Looks like you have that crazy 6 too

the 9 in my may 29 date stamp looks like the upside down "b"---my car is a bb vin 121115 pretty close to yours rick---is it still hot in sonora jerry?---phil

[Rick S.]

Re: What should be the clearance here?

Joe,
Very interesting. I was thinking that they would change the engine code as necessary, not have a gang stamp for each engine code. Was the rate of production such that it was impracticable to change the gang stamp? Then again, if the guy was clumsy, trying to find the stamp on the shop room floor would have been comical.

Rick

[Joe L.]

Re: What should be the clearance here?

Rick-----

The rate of production at Flint was very high. When I was there on tour in 1992, they were manufacturing ALL small block engines used for ALL GM PRODUCTION and most SERVICE applications on 2 assembly lines.

I know that in 1992 they used different gang stamps for each engine code. As I say, they had a rack full of gang stamps and I watched the line person select different ones for each engine configuration. I have pictures of it around here somewhere.

I do not know, for sure, if the different gang stamp holders for each engine configuration were used in the 60's and 70's. I suspect they did, though.

[Gerard F.]

Re: Looks like you have that crazy 6 too

Phil,

Starting to cool down to the mid 90's from the mid 100's. Never thought 95 would be a relief.

Jerry

[Rick S.]

Re: What should be the clearance here?

Joe,

Thanks for the education. I can't thank you and others enough for giving us newbies an insight what took place in the various plants.

Regards,
Rick

[John H.]

Re: What should be the clearance here?

Rick -

In the 60's-70's, Flint V-8 ran at 300 per hour (5500 per day); 170-190 per hour on Line #1, and 110-120 per hour on Line #2. Machining departments ran three shifts, assembly ran two. Saginaw Foundry supplied over 60,000 castings to Flint V-8 every day.

[Rick S.]

Re: What should be the clearance here?

Wow, that was one humming factory. Thanks for the info John

Rick