Single groove L34 water pump pulley

[My68SS]

Hi all,
I've noticed pics on ebay of single groove water pump pulleys p/n 3905995, that have a slight ripple in the outer edge as per below pic, whereas others of the same p/n are smooth. 
What normally appeared in Camaro's using this pulley, smooth or rippled?

[big iron]

Rob,
Does the pulley have a CF on it?
Bob

[My68SS]

Not sure about that particular one, but there are others on ebay that are quoted as being stamped 3905995 CF and have the exact same ripple edge.
I have one that is also stamped with the CF and is smooth.

[big iron]

Rob,
According to a CRG report, pulley 3905995 has been found without the broadcast code (CF). 
Note how the outer edge is so uneven. I have never seen a GM pulley formed with edges like the one you have shown.
I do not think that pulley is GM but Rich F or John H could give you a more knowledgeable answer.
Bob

[My68SS]

Interesting, if you search 3905995 in ebay, you will find two auctions with this pulley claiming them to be nos. One is pictured with the GM box it came in.
Perhaps they are GM, but re-issues from another manufacturer who stamping process made them a bit differently?

[tmodel66]

Not sure what application these pulleys are used on but I have definitely saw them used on GM products.

[Boston14]

Here's a picture of my original 1969 L48/M-38 single groove water pump pulley (with p/s). This pulley is the same for 307, 327, and 350 small blocks with p/s without a/c. It is also the same pulley for L35 & L34 big blocks base and p/s cars without a/c.

boston14

[My68SS]

Thanks Boston14,
That pretty much seals it for me, that the ripple edge is what's most commonly found and further confirmed in Stiney's thread here
http://www.camaros.org/forum/index.php?topic=7096.msg46863#msg46863

It could be that ripple is assembly line and smooth is later spare part from a different stamping machine.

[Steve Shauger]

Thanks Boston14,
That pretty much seals it for me, that the ripple edge is what's most commonly found and further confirmed in Stiney's thread here
http://www.camaros.org/forum/index.php?topic=7096.msg46863#msg46863

It could be that ripple is assembly line and smooth is later spare part from a different stamping machine.

The ripple  edge is typical. I would note it's only found on the front edge (towards the fan) not the back edge (towards the pump).

[My68SS]

It is also the same pulley for L35 & L34 big blocks base and p/s cars without a/c.
boston14

Just realized that statement has [partially] thrown a spanner in the "pulley works" as per my ramblings in this thread, but would be correct for 67's
http://www.camaros.org/forum/index.php?topic=6917.msg49348#msg49348

I say that because according to the 68 L34/35 pulley list, what you say would still seem correct. However according to the emissions report, all 68 [and 69] bb camaros, manual and auto, were fitted with AIR which requires at least a two groove water pump pulley. The one exception to this is exports which were KD1 [AIR delete]
Hence my assumption that the '68 L34/35 w/o smog pulley list referred only to exports.
However, this flies in the face of what's fitted to my car - an export L34 w/o AIR but with a 2 groove water pump pulley. 

I also note that the 69 pulley list does not have a "w/o smog" for L34/35. Perhaps the 68 list is not entirely correct for camaro, with the 'L34/35 w/o smog' applying only to 68 chevelle and full size with 396/325 thm auto?

Thanks paceme for your added confirmation 

[Steve Shauger]

It is also the same pulley for L35 & L34 big blocks base and p/s cars without a/c.
boston14

Just realized that statement has [partially] thrown a spanner in the "pulley works" as per my ramblings in this thread, but would be correct for 67's
http://www.camaros.org/forum/index.php?topic=6917.msg49348#msg49348

I say that because according to the 68 L34/35 pulley list, what you say would still seem correct. However according to the emissions report, all 68 [and 69] bb camaros, manual and auto, were fitted with AIR which requires at least a two groove water pump pulley. The one exception to this is exports which were KD1 [AIR delete]
Hence my assumption that the '68 L34/35 w/o smog pulley list referred only to exports.
However, this flies in the face of what's fitted to my car - an export L34 w/o AIR but with a 2 groove water pump pulley. 

I also note that the 69 pulley list does not have a "w/o smog" for L34/35. Perhaps the 68 list is not entirely correct for camaro, with the 'L34/35 w/o smog' applying only to 68 chevelle and full size with 396/325 thm auto?

Thanks paceme for your added confirmation 

Just for clarificationin 69 you

It is also the same pulley for L35 & L34 big blocks base and p/s cars without a/c.
boston14

Just realized that statement has [partially] thrown a spanner in the "pulley works" as per my ramblings in this thread, but would be correct for 67's
http://www.camaros.org/forum/index.php?topic=6917.msg49348#msg49348

I say that because according to the 68 L34/35 pulley list, what you say would still seem correct. However according to the emissions report, all 68 [and 69] bb camaros, manual and auto, were fitted with AIR which requires at least a two groove water pump pulley. The one exception to this is exports which were KD1 [AIR delete]
Hence my assumption that the '68 L34/35 w/o smog pulley list referred only to exports.
However, this flies in the face of what's fitted to my car - an export L34 w/o AIR but with a 2 groove water pump pulley. 

I also note that the 69 pulley list does not have a "w/o smog" for L34/35. Perhaps the 68 list is not entirely correct for camaro, with the 'L34/35 w/o smog' applying only to 68 chevelle and full size with 396/325 thm auto?

Thanks paceme for your added confirmation 

Rob, I believe the single groove pulley was used on all cars. The possible exception may be if the car had a/c, I don't recall. Below is pic of the typical pulley belt configuration for a 69 BB.

[My68SS]

Hi Paceme,
Nice engine bay! Is it yours?
Seems the arrangement of items and belts was completely different in 69.
68's have a low mount ps pump, down level with the crankshaft pulley and the alternator is on the other side, above the ps pump. a/c pump is were your alternator is.

btw, if it is your engine bay, check your AIM for routing of ignition leads 5 and 7. They were kept as far away from each other as possible because those two cylinders fire sequentially.
A crossfire from 5 to 7 would be very bad news for 7.

[Marty]

I put the pulley report together many years ago. The 68 AM has errors in it and the pulley report was an attempt to identify the correct pulleys. The smog information was not known at that time. I have had most of these pulleys in the past and I still have some in a box.

The C60 crank pulley is larger and the water pump pulley that goes with it is smaller.

There is a single groove BB short water pump pulley but I don't think it was used in 68, only 67.

I think the 3905995 water pump pulley's without the ribs were used in earlier years (mid-60's).

I hope this helps answer some questions.

Martin

[My68SS]

Marty, thanks for the heads-up 

There is a single groove BB short water pump pulley but I don't think it was used in 68, only 67.

That gets my vote.

I think the 3905995 water pump pulley's without the ribs were used in earlier years (mid-60's).

That should get Boston14 on the hop!! 

[Boston14]

Rob, in my previous post, all references were to 1969 models.  Sorry if I didn't make that clear.