C3 BB questions

[Rob M.]

Hi all,

Since I'm relatively new in the C3 Corvette business I probably have some pretty straight forward questions whileI'm studying my car (with the NCRS TRG in my hand).

In my car the AIR pump is not fitted under the hood. Did all the '69 BB cars have an AIR pump or were they also delivered without one?

greetings,
Rob.

[Clem Z.]

Re: C3 BB questions

the pipe plugs in your exhaust manifolds are a pretty good indicator that it had a smog pump

[Joe L.]

Re: C3 BB questions

Rob----

ALL 1969 Corvettes were originally equipped with the AIR system-----small blocks, big blocks and, likely, medium blocks if they had built any. This included L-88 and ZL-1 and regardless of where originally delivered.

[Dick W.]

Re: C3 BB questions

And to answer the next question before it is asked, all export cars in 1969 were AIR equipped

[Joe L.]

Re: C3 BB questions

Dick------

And, for anyone that disputes that, I'd like to see an original-type fuel line with GF-432 filter and bracket for base, L-46 or L-36 that's configured for a non-AIR-equipped car. If such cars existed, then there would have to have been a pre-made fuel line to accomdate the non-AIR configuration. There's NO WAY that GM would have built these cars with the fuel line and bracket just "hanging out there". I strongly doubt that they would have built one with a assembly plant fabricated fuel line, either.

I have NEVER seen a 1968 or 1969 that someone contended was built without AIR that had a factory-like fuel line. And, I don't think that I will ever see one, either.

[Rob M.]

Re: C3 BB questions

If you look again at the picture I posted on the original message you might notice the pulley has three grooves, does this mean it needs another device to be hooked up to this (using an additional belt) or is this not certain since it was an option device but still the 'three groove' pulley was used if you didn't order the option (e.g. airco) ?

Sorry for these obvious questions but I really have to get into C3 engine configuration fast to avoid incorrect ordering of parts or restoring errors!!!

greetings,
Rob.

[Joe L.]

Re: C3 BB questions

Rob-----

All 1969 Corvette big blocks used a 3 groove waterpump pulley. L-88/ZL-1 may have used 2 pullies, a 1 groove + a 2 groove, sandwiched together to provide 3 grooves, while all other 1969 big blocks used a single, 3 groove waterpump pulley. All 3 grooves were utilized with no "spare" grooves. The outermost groove was for the AIR pump. The 2 inner grooves served various functions depending upon engine and installed options (i.e. C-60 and/or N-40).

[Rob M.]

Re: C3 BB questions

Hi Joe,

I have no airco, powere steering or any other options on the car so one groobe would be used for the alternator, one for the AIR setup, so what would the last groove utilize?

greetings,
Rob.

[Tony H.]

Re: C3 BB questions

Rob,
Others will hopefully verify. I think the inner most groove would match up to the inner most crank pulley groove (as it does on my 1970 big block).
Tony

[Joe L.]

Re: C3 BB questions

Rob------

The inner groove is for a captive belt that runs betwwen the inner crank groove and the inner waterpump pulley groove. Since this is a captured style belt, its length has to be exact. The belt was 31-7/8" long and you won't find that size in the aftermarket. You can use a Quanta reproduction or you can use a GM 31-1/2" belt of GM #9433715. This belt will be quite "tight" and you're probably better off to use the Quanta belt. Dr. Rebuild might even have a few NOS GM #3952336 belts available.

[Rob M.]

Re: C3 BB questions

Thanks Joe, I'll order one right away. any tricks to get it installed?

greetings,
Rob.

[Joe L.]

Re: C3 BB questions

Rob-----

The easiest way I've found at this point is to remove the crank pulley, install the belt over the waterpump pulley and crank pulley. Then, with the crank pulley as flat against the balancer as possible, pull the pulley down until the inner locating lip of the pulley "engages" the hole in the balancer. Last, rotate the pulley to align the bolt holes.