LeMans Pete

The typical topics are "how to remove my smog pump", but I'd like to know a little bit more about the different years and models. When I was looking to purchase my '69, Steve pointed out my incorrect smog pump. I thought, "who the hell removes and replaces the smog pump?" Here's my pump, in pretty poor condition, and a picture of Steve's perfect engine bay (I'm hoping he doesn't have a copyright yet on this picture).







Mine has the vent on top, which is not correct for a '69 small block. This possibly appears correct for a '68, comparing to avalonjohn's restored pump.

Where are the identifying mark's on the smog pumps? I tried to snap a picture of the pulley's #s, but very hard to read, and don't seem to match the digits for a '69 pulley.

427SIXPACK

It's NOT a 68 pump either 68's have WHITE fans !!

Easy Mike

The NCRS Judging Guide says the AIR pump casting number is under the fan and not visible with the fan in place. 68s and early 69s had the pressure relief valve on the case.

LeMans Pete

Excellent, thanks Mike. Is this the 7801149? Is this also the location of the date stamp?

As Sixpack points out, the fan is supposed to be white (for a '68). From Steve's engine bay, his fan looks white as well, which is correct according to Rick Bozzoco. Any knowledge on which years had black fans and were vented?

Mike Ward

, not sure when the case went from integral valve to the later style. Possibly the OP's pump is correct as is. (?)

What date code in on the pump?

Rowdy Rat

Typically, there is a machined area on the pump body where the date is stamped. You'll need a mirror to see it as installed in the car as it faces down (toward the ground).

Casual observation and past experience lead me to believe that it is not the correct pump for the car, but it would be interesting to see what date is stamped on the pump.

Regards,

Stan Falenski

Rowdy Rat

With regard to your other questions...

Relief valve is typical for 1968-1969 L-88s (and ZL-1s for that matter), but other GM products used them too so it is not an L-88 exclusive.

The black fan, if I recall correctly, came into service as a production part in late 1972 and of course was available as a service replacement part from that point as well.

Regards,

Stan Falenski

LeMans Pete

Thanks Stan. The original owner cracked the block in 1972 and replaced it with a CE block. I would've thought that all the original components would've been stripped off the original block and transferred to the new block.

I'll take a stab at finding the date codes. Were the service replacement pumps vented?

vettebuyer6369

Yes, early '69s did have pumps with the valve.

Also, just because a pump does not have the white fan, its doesn't make the pump wrong. It makes the fan wrong. They were plastic, you know. The white fans are available.

There is a machined pad on the underside of the pump that has the date stamp. The format looks like "2359SM." There are variations, but basically the first 3 numbers are the Julian date of the year, and the fourth digit is the year... look for a 9 (or very late 8) on one for your car if you want it correct.

The pump casting number is under the fan and not visible.

Also, I think (going from memory) but the 69-72 pumps all are very similar visually and can be used for cosmetic appearance applications on a '69. Differences are the little hole on top is missing, and there's size issues that are noticable if you look close.

PS, Pete, my attorney wants to speak with you about that copyright thingy...

vettebuyer6369

I neglected to take a proper date code photo (shame on me)... but:

In the picture below, you can get a good idea where the number is. Actually, if you blow the photo up 200% and look, you can see a couple of the numbers.

On the short boss on the underside, you can see a rounded out machined section. The number is there. This faces down when installed. This is a typical smog pump for this application.

vettebuyer6369

This is the boss where it's found:

LeMans Pete

Not the easiest part to get a picture of installed, but backwards in a mirror I see 07421Y. The last 3 make perfect sense: 2 - 1972; 1 - 1st shift; Y - Ypsilanti Plant for the vented pump.

I'm not sure of the 1st number being a "0".



Further questions: in 1972, which cars used a vented pump?

vettebuyer6369

Also, I have found getting a proper diverter valve to be much harder than an acceptable smog pump.

BoeingDriver

It's the 74th day of 1972, 1st shift. Y is not for the plant, it's for the pump model, in this case one with the pressure relief.

avalonjohn

Is your car an L-46? If so, even harder to find than the right pump and diverter is the pulley. If your pulley is original you are WAY ahead of the game. Should be a 3932458 DA deep groove.

What is the build date of the car? I have a close friend with hundreds of pumps (the guy who rebuilt mine).

LeMans Pete

You're 100% correct. I was propogating an assumption by Rick Bizzoco that the vented pumps were assembled at the Ypsilanti plant (hence the Y), and that the non-vented pumps were assembled at the Saginaw plant (hence the S).

John, it is an L46. Funny, it does have the correct pulley. I would have thought this would have disappeared with the original pump.



The build date is September 13, 1969. Let me know if he has any correct pumps around and we can work out a deal.

avalonjohn

Sure thing. Good thing on the pulley. If you're bored, check out the asking prices of an original 458 pulley. Most ask near 1k. They usually sell overnight at $600!!!

I'll call Joe tomorrow. I know he has one. Do you have the right diverter? Looks right to me. Should be a 29199. Part number is hard to find sometimes.

LeMans Pete

Thanks John. I'm not sure about the diverter, I cannot find the PN with it installed.

$600 for a pulley is ridiculous. You have me questioning if I should be selling this instead of finding the missing pieces.

And I have the correct 1100884 alternator

avalonjohn

is it an 884 or 882?

Reason I ask is that I have a one owner L46, early August 69 build which isnot too far off from yours. No AC or TI. The car is all original and looks it. The alternator on my car is an NS stamped 1100882 61a. It is correctly dated for the car. According to NCRS this should only be for a BB car, or a SB with AC or TI. According to NCRS the alternator should be an 1100859, which I now have, just not on the car.

Is your car AC or TI? Is it dated correctly for your car? Thanks, john

LeMans Pete

John,

I don't have it in front of me, but I'm pretty sure it was an 884, dated 9J4 (will confirm tonight). Yes, my car does have AC, and with that date, is correct for the car.