Timing belt question

[Stevie]

Hi guys,

i'm a little confused about the timing belt of my 140cui.

In this ebay-sale a timing belt is offered:
http://cgi.ebay.com/ebaymotors/ws/eBayI ... 0349415995

It says: "Note: 91 Teeth, Use w/S426 &S427 gears" (supplier: Clevite TB12)

If I check rockauto.com they say for my '75 model: "99 teeth (supplier: CLOYES # B012)

I only got the workshop manual, not the parts catalogue. But every source I found says that there are no differences in the belt.

Could someone please check, what timing belt is correct for my vega ?

Thanks,
Steffen

[Stevie]

oO...no one here knows..?

[Jitterbugdude]

I'm pretty sure the difference is due to the water pump. The earlier Vega's had a different number of grooves on the water pump than the later (76 and up?) vega's. Randy B

[hammerdown7]

Steffen,

I have never heard of a different belt and changing the pulleys doesn't make any sense. I would ask them where the information came from on the 91 tooth belt. The standard Vega water pump pulleys are all the same, they have 7 grooves, a Cosworth water pump has 9 grooves.

Dick

[Jitterbugdude]

Now I'm confused. After I read Dick's response I realized I must have been mistaken. All Vega's have the same timing belt and hence water pump, the cosworth being different. But when I get on RockAuto, they show an ACDelco # for a 72 vega and a different ACDelco # for a 76. NAPA, on the other hand shows the same water pump for both years. I'm going to go on the assumption that there is something screwy with Rock Auto! Randy B

[Stevie]

Well... here's the answer of the seller on the ebay-auction:
"Well, that is a good question. I went to Melling and they said it had 91t. I went to Cloyes, and they said it had 99t. So I got the belt off the shelf and counted the teeth. There are, in fact, 91t on this one. It has 7 raised grooves to fit into the 7 groove pulley. Do you have your out yet? Have you counted the teeth? I think that Cloyes has a misprint in their book. Please let me know your thoughts"

Does anyone here got a belt for the standard vega available for counting ? I have mine still installed...
Now I'm confused even more..

Steffen

EDIT: now when I'm thinking about it again: where are the grooves on the pulley ? I thought that the water pump pulley is only powered by the flat backside of the belt (and only the crankshaft and camshaft pulleys have grooves for fitting into the belt...

[hammerdown7]

Randy,

There are two somewhat physically different water pumps for the Vega. Both have 7 grooves but one has a straight neck and one has an upward tilted neck to clear either the alternator or a/c compressor on an a/c equipped car, I don't remember which.

Chuck, can you check your parts books to come up with the answer?

Steffen, the back of the belt is grooved, not flat, that powers the water pump. The cam side of the belt has teeth which run across the belt, the grooves run longways around the belt.

Dick

[cosvega76]

I have some old engine part catalogs at home, I'll take a look. There certainly would be a difference between a 91-tooth and 99-tooth belt which I wouldn't think would interchange.

Chuck

[cosvega76]

I just looked on the Cloyes website, and it says that a B012 timing belt has 99 teeth. I'll still check at home, though.

Chuck

[Stevie]

Thanks, Chuck...
The timing belt change will be one of the next things...but I dont wanna take the old one out just for counting the teeth...

Steffen

[cosvega76]

I'm finally home long enough to look at some of my vintage engine parts catalogs. As one might expect for timing products, most manufacturers use "industry" numbers for their parts. Interestingly, I show the same discrepancy between two parts catalogs:

In a 1995 NAPA Timing Products catalog, the 25-9012 belt shows 99 teeth, with the sprockets S426 and S427 showing 36 and 18 teeth, respectively.

In a 1998 Melling Engine Parts catalog, the B-012 belt is listed having 91 teeth, with the sprockets S426 and S427 having 36 and 18 teeth.

Could it be just a slight adjustment difference between the two belts? I suppose 8 teeth on a belt would make about an inch or so of difference in length.

Chuck

[hammerdown7]

Chuck,

I'm quite sure there is not enough adjustment in the water pump to take up an inch longer or shorter belt. It's looking more to me like one of the tooth counts is a misprint.

Dick

[Stevie]

Thank you for checking this out.
I will order now the belt and I guess if will fit...

Steffen

[73astregt]

just an idea here (excuse me if someone already mentioned this) maybe the shorter belt was to be used in a rebuild where the head was planed down to cure a warpage problem? like getting a shorter timing chain for a chevy v8 that has been line bored and decked.

[res0o7eb]

I counted it twice.
91 Teeth, if you are talking about the 'female' part of the belt that meshes with the 'male' part of the gears.
Otherwise, it's 92 teeth on the belt from the stock 140 SOHC in my 1976 Vega GT.

The Cosworth Vega belt is much bigger - needs to fit over two cam gears(sprockets) instead of one, you know.