[SCG] (Second Try) Re: When did belt guards appear on 1964 Corvairs?

[David Newell]

(Sorry for the incomplete first attempt...due to my eyesight my left thumb sometimes hits the Control key instead of Shift and sends emails before I've finished them!)

Bill,
Thanks for bringing up this interesting subject. I think you're right, Bill, in that the 3-27-64 Assy Manual note simply revised the existing drawing (which already showed the guards) and added a dimension to it. I don't have the previous pages in my book, sorry.

But I found TSB 982 which only went to the field and not to dealers: "Corvair and Corvair 95 Blower Belt Front and Rear Guides" dated 3-18-64. It states that "All Corvair Models produced after November 29, 1963, are equipped with subject guides to afford greater belt durability and to prevent belt roll-over."

The primary purpose of the bulletin was to show how the guides could be field installed on 61 through early 64 Corvairs. Four pages of instructions and drawings were included, mostly devoted to fabricating a bracket for the front guide and welding it to the top shroud. If anyone's interested, the next time I have my laptop hard wired to my non-Wifi scanner I can scan the bulletin for you.

I checked the '64 GM Proving Ground Vair production test car photos but the only one photographed after 11-29 was a non-A/C 927, shot on 3-9-64, which had the guards. The others, including and A/C car, didn't have them.

I have one more source to check, the monthly quality reports, to see if there are any comments about adding the guards as a fix for a chronic quality issue. I can't find them right now though.

Since no exclusions for A/C were mentioned in either the Assy Manual or the bulletin, I can't see any reason to believe that '64 A/C cars didn't use the brackets.

Hope this helps,
Dave

--------------------------------------------
On Wed, 9/6/17, William Hubbell <wjhubbell at gmail.com> wrote:

 Subject: Re: When did belt guards appear on 1964 Corvairs?
 To: larry at vairshop.com
 Cc: "Stock Corvair Group" <scg-list at corvair.org>, "Dave Newell" <chevrobilia at yahoo.com>, "Larry Claypool" <vairshop at sbcglobal.net>
 Date: Wednesday, September 6, 2017, 4:40 PM
 
 Thanks Larry - I don't know why I didn't
 think of that!   
 
 According to the 1964 Assembly Manual,
 Section 6, Sheet A4.00 titled "Belt and Belt Adjustment, on
 3-27-64:
 Note 6 :  "View A Revised and Dim
 Added".  (View A shows the two guides and the
 dimensions for adjusting them)
 Note 7: "Dim Instructions Revised"
 (This refers to the dimensions for
 clearance from guide to top edge of pulley after belt is
 tightened)
 Note 8: "Tensioning Note Revised"
 
 I checked the 1963 Assembly Manual and
 there is a similar page for "Belt and Belt Adjustment ",
 Section 6 Sheet A 9.00.  The main photo on this sheet
 is nearly identical to the main photo in the 1964 manual,
 but View A is quite different and, of course, does not show
 belt guides.
 
 Therefore it is a possibility that the
 belt guides may have been added around 3-27-64, at the time
 View A and belt tensioning note was revised.  However,
 note 7 seems to suggest the possibility that there could
 have been an earlier version of view A showing the belt
 guides with a different clearance between the fan pulley and
 top shroud belt guide, so this date is not certain. 
 
 I also checked the 1964 Assembly Manual
 Air Conditioning section but find no mention there of belt
 guides.  I rather suspect they were not added to the
 A/C engine but I'm really not sure about that. 
 
 Bill
 
 On Sep 6, 2017, at 6:01 PM, larry at vairshop.com
 wrote:
 
 hi Bill
 as a starting point check the assembly
 manual and see what date is listed for the guards. that
 doesn't mean they entered production then, but it would
 *not* have entered production *before* then. rear refers to
 one at idler pulley, and yes they are guides.
 
 there may be a technical service
 bulletin that tells techs how to adjust these, and it may
 note when they came into production. i'll look when i get a
 chance, but it's not likely to be soon.
 larry
 
 
 
 mQuoting William Hubbell <wjhubbell at gmail.com>:
 
 > Do we know the approximate date
 when the top shroud and idler pulley belt guards were added
 to the Corvair engine?  Also, do we know if Early Air
 Conditioned cars used either of these guards?
 > 
 > The guides definitely first
 appeared sometime in the 1964 model year, as there are two
 top shroud part numbers listed in the March 1, 1964
 Corvair-Chevy-Chevelle parts catalog:
 > 
 > - 3794216 Shroud Assembly, Upper,
 62-63 Corvair, FC, 64 Corvair (exc. Turbocharger) (1st
 design)
 > - 3851838 Shroud Shroud Assembly,
 Upper, Corvair, FC (exc. Spyder) (2nd design)
 > 
 > There are likewise two part
 numbers for 64 Spyder top shroud:
 > 
 > - 3848398 Shroud Assembly, Upper,
 64 Corvair, Spyder (1st design)
 > - 3851840 Shroud Assembly, Upper,
 64 Spyder (2nd design)
 > 
 > There is apparently only one
 listing for 64 FC:
 > 
 > - 3848400 Shroud Assembly, Upper,
 64 FC
 > 
 > Additionally, the index listing
 for "Guide, Blower belt idler pulley" points to section
 1.060.  In that section I find the following:
 > 
 > - 3851844 Guide, front, 64
 Corvair, FC (exc. Air Cond.)
 > - 3851845 Guide, rear, 64 Corvair,
 FC
 > 
 > I'm not sure if "guide" is the
 belt guard.  If so, is the "front" the guide that goes
 on the upper shroud and "rear" the guide that goes on the
 idler pulley?
 > 
 > The parts book does not list the
 dates for "1st design" and "2nd design" - do we have any
 idea when this change took place?   I already looked in
 my Clark's reproduction Chevrolet Service Bulletins and did
 not find anything, but as these are edited reproductions I
 might be missing the announcement.
 > 
 > Bill Hubbell
 
 
 
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