67 Crankshaft pulley

[Joe D.]

Looked at a 67 327-350hp car with power steering. The crankshaft pulley had 3 grooves. One was the alternator, second was the power steering and the groove closest to the fan was empty. Just wondering what the third grooive was for, a/c? Happy New Year. Thanks, Joe DeLuca

[John D.]

Re: 67 Crankshaft pulley

joe,

Just peeked at the AIM and it shows the center pulley location (#2) is for the A/C belt in cars with N40 and C60. Don't know if that's correct or not....


jd

[Patrick T.]

Re: 67 Crankshaft pulley

It's probably the "captive belt", which only goes around the crankshaft pulley and the water pump pulley. They are a PITA to put on. It's there in case your alternator belt breaks, you will still have a redundant belt to turn the water pump until you can make it to a garage to get fixed.

So when are you picking up the car?

[Joe R.]

Re: 67 Crankshaft pulley

Looked at a 67 327-350hp car with power steering. The crankshaft pulley had 3 grooves. One was the alternator, second was the power steering and the groove closest to the fan was empty. Just wondering what the third grooive was for, a/c? Happy New Year. Thanks, Joe DeLuca

If the car does not have AC, there should not be a third groove on the crank pulley. The third groove was only installed on cars with AC.

If the crank pulley arrangement uses original GM parts, the third groove is actually a separate, add-on pulley that nests inside the 2-groove crank pulley. So, it is easy to remove.

[Joe L.]

Re: 67 Crankshaft pulley

If the car does not have AC, there should not be a third groove on the crank pulley. The third groove was only installed on cars with AC.

If the crank pulley arrangement uses original GM parts, the third groove is actually a separate, add-on pulley that nests inside the 2-groove crank pulley. So, it is easy to remove.

Joe and Joe------

That's correct. If the car is an L-79, then the only way it should have had 3 belt tracks on the crankshaft pulley is if it also had C-60 and N-40.

However, if the car is actually base engine car, then it would have 3 tracks if it had N-40 and regardless of other belt driven options. In the case of a base engine car, one of the tracks was used for a captive belt.

As Joe R. stated, all C2 small blocks that had 3 tracks on the crankshaft pullies used a 1 groove pulley sandwiched onto a 2 groove pulley. No 3 groove crank pullies were ever originally used on C2 small blocks or, for that matter, C2 big blocks, either.

[Gerard F.]

Re: 67 Crankshaft pulley

Looked at a 67 327-350hp car with power steering. The crankshaft pulley had 3 grooves. One was the alternator, second was the power steering and the groove closest to the fan was empty. Just wondering what the third grooive was for, a/c? Happy New Year. Thanks, Joe DeLuca

Joe,

I've always thought that the 3rd groove of the crankshaft pulley on a 327, closest to the fan, was always for power steering.

[Joe D.]

Re: 67 Crankshaft pulley

The owner emailed me this morning and said it was for the a.i.r.??? He said there was bracket on the engine for the a i r when he first bought the car. I thought it would run on the pulley with the alternator? Happy New Year, Joe DeLuca

[Joe L.]

Re: 67 Crankshaft pulley

The owner emailed me this morning and said it was for the a.i.r.??? He said there was bracket on the engine for the a i r when he first bought the car. I thought it would run on the pulley with the alternator? Happy New Year, Joe DeLuca

Joe-----


The owner is mistaken. The air injection reactor pump for all 1967 Corvettes equipped with K-19 was driven from the waterpump pulley set. In no configuration did it involve a belt which also encompassed any crank pulley. So, any 3 groove crankshaft pulley configuration was in no way related to AIR.

[Joe D.]

Re: 67 Crankshaft pulley

Thanks Joe. I am still confused about the 3rd groove on the pulley. I am not sure if the car came with it or the original was replaced with it. I do not know if it's that big of a deal.

[Joe L.]

Re: 67 Crankshaft pulley

Thanks Joe. I am still confused about the 3rd groove on the pulley. I am not sure if the car came with it or the original was replaced with it. I do not know if it's that big of a deal.

Joe------


The part number on the pulley or pullies would be helpful in figuring this one out.

If the crankshaft pulley set-up is original to the car, it might be very significant. It could be the "clue" that indicates the car is/was actually a 300 hp that's been converted or "passed off" as an L-79.

[John H.]

Re: 67 Crankshaft pulley

Joe------


The part number on the pulley or pullies would be helpful in figuring this one out.

If the crankshaft pulley set-up is original to the car, it might be very significant. It could be the "clue" that indicates the car is/was actually a 300 hp that's been converted or "passed off" as an L-79.

Also the presence/absence of a balancer bolt - the 350hp crank snout was drilled/tapped and used the bolt, and the 300hp crank wasn't drilled and used a press-on balancer.

[Joe D.]

Re: 67 Crankshaft pulley

Joe, Did the base engines use a 3 groove pulley?

[John H.]

Re: 67 Crankshaft pulley

Did the base engines use a 3 groove pulley?

Nope. The 300hp engine used a single-groove crank pulley - if it had power steering, it got the "add-on" single-groove pulley to drive the pump.

[Lawrence S.]

Re: 67 Crankshaft pulley

My original 67 L-79 with N60 only has two grooves on the crankshaft pulley.

[John D.]

Re: 67 Crankshaft pulley

Nope. The 300hp engine used a single-groove crank pulley - if it had power steering, it got the "add-on" single-groove pulley to drive the pump.

john

Was that for all base engines ? What about if it had C60 and N40 ? Would it have the double pulley and then the add on ?.

The AIM shows a car with C60,N40 and K19 has no less than 5 seperate fan belts !!

thanks