'67 L79 with poswer steering
I have had a '67 Coupe with L79 and power steering since 1987. When I got the car, it showed 67,000 miles, which looked like it could be true. It was a little worn around the edges, but overall was in pretty good original shape. As far as anyone who has looked at it can tell, it has the original engine. Last week, I had to replace the harmonic balancer, and while I was at it, I thought I'd change the belts on the car and replace them with reproduction belts. I ordered the proper Quanta belts from LIC. When I got them, the power steering belt looked too long. To make a long story short, my car has a two groove water pump pulley and a short power steering belt (like a 300 hp car), while the AIM shows a three groove and the longer belt that goes around the water pump pulley as well as the crankshaft pullley and the power steering pump for an L79 with N40. My question is : "Could my car have come this way from the factory?" I know that the AIM's were produced early in the model year and don't reflect running changes, so I may be OK. I don't see any reason that spmeone would have made his change. Could some of you guys with '67 L79's with power steering check out the PS belt and let me know what you find? I'd hate to hunt up a three groove pulley and find out it was superced later in the year. By the way, the car was built in mid march 1967. Thanks.
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Re: '67 L79 with poswer steering
Dennis,
Are you referring to 1967 AIM page N40-A6?
Does your L79 have power steering AND air conditioning, or just power steering?
The drawing on N40-A6 looks like a 3-groove crankshaft pulley with N40 & C60, or 2-groove with just N40, but in both cases it looks like the Power Steering crankshaft pulley is an add-on pulley (Item 7, either GM 3751232 or GM 3850838 with C60) that fits into the standard crankshaft pulley.
I have seen pictures of GM 3751232, it is a single-groove pulley, confirmed by Mark Gorney's pulley chart, which also shows the GM 3850838 as being a 2-groove pulley.
There's probably more to it, hopefully some of the pulley experts will reply,
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Re: '67 L79 with poswer steering
Check the archives about this, I have read that the Quanta belts were not the correct length for some L79 options, and I don't know if this problem has been corrected.
If the pulleys have been changed from the factory configuration, it seems this is often because someone wanted to put a deep-groove pulley set on a car that came from the factory with standard-groove pulleys.
If I understand correctly, a standard L79 (no N40, no C60) had deep-groove pulleys. The L79 with C60 (no power steering) had deep-groove pulleys. I think the L79 with power steering only (no C60) also had deep-groove pulleys, but an L79 with power steering AND C60 had the standard-groove pulley set.Comment
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Re: '67 L79 with poswer steering
As my post correction said; I had a case of "option code dyslexia". My car has power steering only; no air conditioning or anything else which would effect the pulley or belts. You are refering to the same page I referenced. N40 with C60 uses a short belt and (most likely) a two groove pulley. L79 with N40 only uses a long belt and a three groove pulley. I have had this car long enough to know it was never an air car,Comment
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Re: '67 L79 with poswer steering
or L79 + N40 + C60 + K19.
I don't know why the 67 AIM (UPC N40-A6) shows Item 7 as applicable to both cars with AND without C60, that must be an AIM error.
My guess is that all you need is the 2-groove deep-groove GM 3858533 crankshaft pulley, with the alternator/water pump belt on the rearward groove and the power steering belt on the forward groove, and should be the long belt going around both the water pump pulley and the crankshaft pulley. I don't know why the short belt would not be preferable, but GM must have had a reason for the longer belt routing. As for whether it's possible your car came from the factory with the short belt, it seems almost anything was possible to keep the assembly line moving.
That's the best I can do!
John or Joe will know, if they see this Thread, and hopefully someone with your L79-N40 only option combo will post their belt set-up too.
Edit: The 67JG does say that power steering cars with either C60 or K19 use a triple-groove pulley (twice, under Crankshaft pulley and Water pump pulley sections, p. 86), but I have that crossed out, I think it is a JG error.Comment
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Re: '67 L79 with poswer steering
Just to clarify things a little. There is no problem with the crankshaft pulleys. They will work with either configuration. The problem is that the two groove pulley on the water pump has no provision to handle the long belt; it would need a third groove in front of the existing grooves to work properly with the long P/S belt. Ther is no way that either of the other grooves would line up with the PS pump.Comment
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Re: '67 L79 with poswer steering
Dennis------
First of all, no Corvette small block ever used a three groove pulley for either the balancer or water pump pullies. Some did use a 2 groove sandwiched with a 1 groove but none used a 3 groove pulley. Your application did not even use a sandwiched configuration for either water pump or balancer.
Your application used a very simple pulley configuration. A 2 groove water pump pulley and a 2 groove crankshaft pulley. One belt connected the balancer, water pump, and alternator pullies and the other connected the balancer, water pump, and power steering pump pullies. The power steering pump pulley was a single groove, cast iron, "drop down" pulley.In Appreciation of John HinckleyComment
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Re: '67 L79 with poswer steering
Joe,
Thanks for the info, but is my car correct or not? There is no way the crankshaft pulley and the PS pulley (which now are aligned correctly) will align with the two groove water pump pulley that is on the car (and seems to have been there forever). BTW the AIM clearly seems to show a three groove WP pulley; perhaps there was a spacer to move the two groove pulley forward? . I don't want to start anything here, but I just want to mnake my car (a driver, which will NEVER be judged) as correcr as possible.Comment
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Re: '67 L79 with poswer steering
Dennis,
According to Gorney's pulley chart, the ONLY L79 configuration with 3 grooves on the water pump (2-groove pulley + 1-groove add-on pulley) involves each of the possible K19 option combos, but no option combo that excludes K19. All L79 non-K19 cars use a 2-groove water pump pulley.
Are you certain that your water pump and crankshaft pulleys are correct? I suspect both should have the GM part number stamped on them, the crankshaft pulley for sure. I noticed that the three bolts securing the crankshaft pulley on UPC N40-A6 are a different part number than non-N40 crankshaft bolts, they are GM 181635 bolts (3/8-24 x 3/4", Grade 5)
The crankshaft pulley bolts called out on UPC L79-A1 are GM 181629 bolts (3/8-24 x 5/8", Grade 5). That's only 1/8" difference in length, but that's the same difference in the unique water pump hub-spacing used on L79s with C60 only (no N40). I don't know if this has anything to do with your situation, but BOTH L79 + N40 only and L79 + C60 only bear the same "HT" engine designation, therefore the L79 + N40 mayComment
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Re: '67 L79 with poswer steering
That sounds incorrect, and would explain why someone, at some point, used the short belt instead of the long belt, in order to make it function without messing with the water pump pulley. It sounds like you have the wrong water pump pulley. My '67 L79 has C60 only, and uses a different 2-groove deep-groove water pump pulley than yours, but the part number is clearly stamped on the outer surface.
Whether the car is ever judged or not, figuring out the correct pulley set-up is helpful for keeping the belts on!Comment
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Re: '67 L79 with poswer steering
I'm looking at N40-A6 right now, and I don't see where you see a 3-groove pulley (or 2-groove + 1-groove combo) on the water pump.
The drawing in the upper RH for N40 + RPO C60 shows the alternator pulley to water pump pulley to crankshaft pulley on the rearward groove, and the A/C compressor belt on the forward-most water pump and crankshaft pulley grooves. The 2-groove crankshaft pulley is changed to a standard-groove depth (GM 3850838) and the single-groove ADD ON pulley (GM 3751232) accommodates the power steering pump belt. The result is two belts in the two water pump pulley grooves, the same two belts on the crankshaft pulley, and the power steering pump belt on the crankshaft ADD ON pulley.
The drawing on the lower LH side of the page (L79 + N40 only) uses the deep-groove pulley set up, with no add on pulley to the crankshaft (I see that Item 7 is also called out for N40 only, but I think it is an error). The alternator to the water pump to the crankshaft pulley belt is on the rearward groove of the water pump & crankshaft pulleys, and the power steering pump to the water pump to the crankshaft belt is in the forward-most groove of the WP and CS pulleys.
Where do you see a 3rd groove on the water pump pulley in either drawing?Comment
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Re: '67 L79 with poswer steering
The belts have been "kept on" for the last 25 years just fine. The diagram on the lower left of N40 A6 seems to show the third groove.Comment
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Re: '67 L79 with poswer steering
Dennis,
If I understand correctly, you currently have a 2-groove water pump pulley, with only the rearward-most groove being used by the belt to the alternator pulley, and the forward groove of the water pump pulley is unused?Comment
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Re: '67 L79 with poswer steering
In my 67 AIM, UPC N40-A6, there are only two belts shown in the drawing in the lower LH portion of the page, occupying the two available grooves on the water pump and crankshaft pulleys. There are three belts in the drawing in the upper RH portion of the page, two belts occupying the two available grooves on the water pump and crankshaft pulleys, and a third belt occupying the add-on crankshaft pulley (forward-most location).
To the best of my knowledge, no midyear Corvette left the factory with an unused pulley groove; if a pulley groove was unnecessary, then a different pulley with the correct number of grooves required was used.Comment
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