Smog Pump Identification / Pulley Removal
I have a smog pump with the number 7801149 on it. The boss has the following embossed: 05291S; I believe this stands for 052nd day of 1969, model 'S'. That would make it a February, 1969 production smog pump. There is no number stamped no the pulley. Could it have been reversed or is it likely a replacement? How does one remove the pulley on one of these pumps? Was the same model smog pump used on all engine sizes?
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Re: Smog Pump Identification / Pulley Removal
Jeff-------
The pump is as you have deduced.
Many smog pump pulleys do not have a part number stamped on them.
These pulleys often "stick" but they can usually be removed by "pulling and slightly rocking" them. Many applications use a spacer between the pulley and the pump.
The same model pump (S) was used on all 1969 Corvette applications. However, L-88/ZL-1 pumps had an external relief valve (like 1968 pumps).In Appreciation of John Hinckley -
Re: Smog Pump Identification / Pulley Removal
Thank you, Joe. I will give it a bit of rocking. Soaking in some penetrating oil for a bit. I have the relief valve to which you refer on my '68.Comment
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Re: Smog Pump Identification / Pulley Removal
Jeff,
if the pump came off a big block and the pulley is original, it will be stamped on the side facing the pump fan and not readable until the pulley is removed. The original big block pulley for a 69 will have a "S" stamped into it as well as the number 3925522. The original pulleys are fairly expensive and not so easy to find and were used on other Chevys from 69.
I think the small block pulleys have numbers too but I'm not too familiar with them.
EdComment
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Re: Smog Pump Identification / Pulley Removal
Thank you, Ed. That is very helpful, too. Soaking overnight did not help my rocking it off this morning. It doesn't help that it isn't mounted . . . leverage is missing. I guess I'll try and find a way to mount it to something so my tugging has some resistance. I think somebody left this thing out in the elements. The steel parts are a bit rusty.Comment
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Re: Smog Pump Identification / Pulley Removal
Hi Jeff,
"I think the small block pulleys have numbers too but I'm not too familiar with them.
Ed"
Here is a photo of mine off my 73 L48, showing the part number used for small blocks 3917234 which face the front when installed. The number is the same for a 69 base motor. It should be 3932458 for the 350 HP motor. Note: Spacer is only used on small blocks. Maybe some light tapping with a small hammer could loosen things up, but I would be very cautious not to break the opaque white plastic fan on the 69.
Good luck!
Have a great day!Jimmy
1973 Convertible
L48,M20,N40
Mille Miglia Red/Oxblood
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Re: Smog Pump Identification / Pulley Removal
Thanks, Jimmy! If the hammer doesn't work I may have to devise a press of some kind.Comment
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Re: Smog Pump Identification / Pulley Removal
Jeff-------
If this pump is from a big block application (i.e. no spacer between the pulley and the pump), it will be a lot harder to remove. That's because there is a light interference fit between the "snout" of the pump and the center orifice of the pulley. Inevitable corrosion over time makes this even worse.
As you mention, you could rather easily make up a "puller". A small, flat steel plate about 1/4" thick with a bolt pattern the same as the pulley, tapped in the center for a press bolt, and 3 longer bolts to thread into the pump hub ought to do it.In Appreciation of John HinckleyComment
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Re: Smog Pump Identification / Pulley Removal
Your puller is exactly what I was designing in my head.
Let's hope it isn't necessary.
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Re: Smog Pump Identification / Pulley Removal
I ended up borrowing a puller from a local auto parts store. The pulley is #3927116. The diverter is #29291. The white faced fan is undamaged. A big block bracket remains attached, too. Thanks for your help.Comment
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