1966 L79 Belt Orientation - Yea or Nay?

[Don L.]

Hi all. I have been working on an beautiful '66 coupe with a L79 engine. This car has manual steering, manual brakes, no AC, no A.I.R., etc.

We just campaigned it at Greenville Regional and it made Top Flight. Woohoo!

While on the judging floor, someone commented on how this car should have a second fan belt, looped between the crankshaft/balancer and the water pump. In looking at the '66 AIM, I see no such belt, regardless of options. I also see no idler or tensioner for a secondary belt, although there are two grooves in each pulley, the outermost being unused. What advice might I get from this group regarding a second belt?

Comments appreciated.

[Rich G.]

[Owen L.]

Re: 1966 L79 Belt Orientation - Yea or Nay?

I also see no idler or tensioner for a secondary belt, although there are two grooves in each pulley, the outermost being unused.

For the 427s, there is no idler either; it's just a very snug fit between the pulleys. The C3s incorporated an idler with A/C.

[Gary B.]

Re: 1966 L79 Belt Orientation - Yea or Nay?

Don, Rich,







In support of that arrangement, here are statements from a number of people who posted their thoughts on this topic on the DB.























Gary

[Robert P.]

Re: 1966 L79 Belt Orientation - Yea or Nay?

Captured belt has to go on the grooves toward the radiator , only way that you will get everything to line up
that is how mine is installed
Bob Peckham

[Gary B.]

[Rich G.]

Re: 1966 L79 Belt Orientation - Yea or Nay?

Thank you, Gary.

Rich

[Don L.]

Re: 1966 L79 Belt Orientation - Yea or Nay?

Thanks to all for contributing to this thread. I didn't know this was a recurring issue. I didn't find anything in archives, although I am the first to admit what a poor i/net searcher I am.

I'll plan to add the secondary belt. I see Quanta offers two different belts - short and long. Both of their belts claim to be a comparable belt to GM's original part # 3837810. Any ideas why there are two different lengths and which one is the one needed for this application? Of course I'll ask Quanta, however, I thought I'd ask here too.

Thanks again!

[Gary B.]

Re: 1966 L79 Belt Orientation - Yea or Nay?

I ended up trying 4 different belts (same item from Quanta) before I got one to fit. Quanta offers a short version (34.4") and a long version (34.8") of belt # 3837810. The first two belts from Quanta measured 34-1/8" and 34-3/16"; both didn't fit; the long version measured 34-5/8" and was way too big.

[Mike E.]

Re: 1966 L79 Belt Orientation - Yea or Nay?

I am confused in this area. Please help. My 7th edition 67 JG on p. 144 has a pulley chart for the HT-code 350-hp motors with no ps or ac as 3905995 with a single groove for the water pump. Then on page 147, top paragraph, it says "The water pump pulleys are stamped steel, each having two belt grooves. The deep groove pulley number 3905995* is used with or without power steering. (*Currently under study)." Every 3905995 pulley I have looked at is a single groove pulley. My 67 is pretty correct under the hood (not a virgin, though) and has a single groove water pump pulley with no discernible part number.
What pulley should I be looking for as correct? FWIW, my 1971 parts book says 63-68 sp.hi.perf. uses 3770245. Also found my Oct. 1, 1967 parts book. 6 pages of water pump pulleys (group 1.062) It lists almost every imaginable combination for 1967 Corvettes except just a plain old sp.hi.perf (L79) with no AIR, no ac, no ps. It does include 63-66 sp.hi.perf. as 3770245.

[Gary B.]

[Bill B.]

Re: 1966 L79 Belt Orientation - Yea or Nay?

While I do not have the Restorer issue with me, I know that there was a water pump pulley feature article with description and part number breakdown in Vol 47 #2 (Fall 2020) of the Restorer. It may be of help in de-mystifying the W/P pulley issue.