Correct Water Pump Pulley L79

[Dan L.]

I have a 1966 L79. I had a reputable garage knowledgeable with NCRS guidelines add power steering a few years ago. They were aware the car was a three time Top Flighted car. I even gave them a copy of the 1966 NCRS Technical Review & Judging manual to ensure everything was done to NCRS standards. Recently I reviewed the pulley configuration and checked the manual for verification - a little confusing. Here is what I have and is it correct? A one groove water pump pulley (attached to the fan) with a belt connecting to the crank pulley and alternator pulley. And a single groove power steering pulley #3834720 with belt connecting to crank pulley. I went back and reviewed all the judging sheets and there was never a point deduct for the water pump, alternator or crank pulleys or belts. Thanks for your input.

Dan
54915

[Joe L.]

Re: Correct Water Pump Pulley L79

I have a 1966 L79. I had a reputable garage knowledgeable with NCRS guidelines add power steering a few years ago. They were aware the car was a three time Top Flighted car. I even gave them a copy of the 1966 NCRS Technical Review & Judging manual to ensure everything was done to NCRS standards. Recently I reviewed the pulley configuration and checked the manual for verification - a little confusing. Here is what I have and is it correct? A one groove water pump pulley (attached to the fan) with a belt connecting to the crank pulley and alternator pulley. And a single groove power steering pulley #3834720 with belt connecting to crank pulley. I went back and reviewed all the judging sheets and there was never a point deduct for the water pump, alternator or crank pulleys or belts. Thanks for your input.

Dan
54915

Dan------


Does this car also have C-60 or K-19?

If not, it is not of the correct configuration. The waterpump pulley should be a 2 groove GM #3848904. The crank pulley should be a 2 groove of GM #3858533. The power steering pump pulley is correct.

[Dan L.]

Re: Correct Water Pump Pulley L79

Dan------


Does this car also have C-60 or K-19?

If not, it is not of the correct configuration. The waterpump pulley should be a 2 groove GM #3848904. The crank pulley should be a 2 groove of GM #3858533. The power steering pump pulley is correct.

Thanks Joe, my car does not have C-60 or K-19. I will contact the garage so they can make the corrections. Am I correct in thinking they removed the correct two groove pulley since all the judging sheets had no point deduct for the water pump pulley?

Dan

[Gene M.]

Re: Correct Water Pump Pulley L79

Added options not virgin to the car is NOT NCRS correct. By puting to print as done here you subject your car to full deduction for added option. Restoring a car for flight judging should be in the sprit of true to the initial out the door from GM configuration not a creation of one’s dream or wanna have.

[Joe L.]

Re: Correct Water Pump Pulley L79

Thanks Joe, my car does not have C-60 or K-19. I will contact the garage so they can make the corrections. Am I correct in thinking they removed the correct two groove pulley since all the judging sheets had no point deduct for the water pump pulley?

Dan

Dan------


I'm not sure exactly what they did. However, from what I got out of your description, I think the configuration they ended up with is unlike ANY configuration originally used. For example, while the GM #3834720 power steering pump pulley is correct for your application, that pulley was NEVER driven by a belt solely running from the crank pulley. Never for any Corvette application EVER. I don't even understand how they got this to work. Some Corvette applications did use a belt running only between the crank pulley and power steering pump pulley but those applications used the stamped steel power steering pump pulley GM #3770509.

[Joe L.]

Re: Correct Water Pump Pulley L79

By puting to print as done here you subject your car to full deduction for added option.

Gene-----


Are you saying that "big brother" is monitoring this board?

[Dan L.]

Re: Correct Water Pump Pulley L79

Joe, as soon as it stops raining here I will take my car back to the garage to determine what they did and have it properly fixed to NCRS specs. Don't know if I will ever have the car judged again but I want to keep it as NCRS correct as possible. Really appreciate the advice and the correct part numbers - I'll begin the search for then now!

Dan

[Gene M.]

Re: Correct Water Pump Pulley L79

Gene-----


Are you saying that "big brother" is monitoring this board?

Joe, I don’t think this board is monitored that closely. But with the issues that you pointed out not being correct plus the words by the owner confirming the power steering option was not virgin to the car, the full deduct is a no brainer call for a judge that knows his stuff.

Up till now the poster had no knowledge of the correct configuration of pulley and drive belts. And it appears the judges looking at the power steering set-up didn’t neither.

[Joe L.]

Re: Correct Water Pump Pulley L79

Joe, as soon as it stops raining here I will take my car back to the garage to determine what they did and have it properly fixed to NCRS specs. Don't know if I will ever have the car judged again but I want to keep it as NCRS correct as possible. Really appreciate the advice and the correct part numbers - I'll begin the search for then now!

Dan

Dan------


The GM #3858533 balancer pulley is still available from GM. Imagine that, a part first released 53 years ago and still available. The finish might be different, though. Most 60's originals were phosphate-finished while later were painted or powder-coated semi-gloss black.

The GM #3848904 was discontinued in September, 1972 and replaced by GM #3995641. Both pulleys are virtually identical except for stamped number which can't be seen when installed on the engine. The 3995641 was discontinued several years ago but might be easier to find than a 3848904.

If possible, I highly recommend using NEW pulleys if you can find them. Certainly, you can find a new 3858533 because you can get that from GM. I'd much rather have a NEW painted or powder coated 3858533 than a USED phosphate-finished 3858533.

[Dan L.]

Re: Correct Water Pump Pulley L79

Joe the 1966 judging manual states the correct pulley for all 1966 L79's with or with out power steering is a deep groove pulley with two belt grooves #3770245. Is the pulley you mentioned - #385833 the same? Thanks

[Dan L.]

Re: Correct Water Pump Pulley L79

Joe my mistake the pulley you mentioned - #3858533 is the crankshaft pulley for all 1966 L79's with out AC. My issue is with the correct water pump pulley - that should be #3770245.

[Joe L.]

Re: Correct Water Pump Pulley L79

Joe my mistake the pulley you mentioned - #3858533 is the crankshaft pulley for all 1966 L79's with out AC. My issue is with the correct water pump pulley - that should be #3770245.

Dan------


Yes, the GM #3770245 is the correct waterpump pulley for your application; my mistake. I think the 3848904/3995641 will work OK but the 3770245 is the better choice. Long-since GM discontinued, though.

[Dan L.]

Re: Correct Water Pump Pulley L79

Joe is the GM part number visible when the water pumup pulley is installed? Thanks

[Joe L.]

Re: Correct Water Pump Pulley L79

Joe is the GM part number visible when the water pumup pulley is installed? Thanks

Dan------

No, it is not.

By the way, the GM #3848904/3995641 is of a smaller diameter than the 3770245 and is otherwise configured differently but it will work perfectly. If one wants to have a higher water pump and fan speed (i.e. to increase cooling performance), then the 3848904/3995641 is, albeit NCRS incorrect, the way to go. I've never known any Corvette to have too much cooling but I've known more than a few which didn't have enough.

[Dan L.]

Re: Correct Water Pump Pulley L79

thanks again!