vacuum advance bottle on distributor

[Vincent McGrath]

Hello from Tasmania, Australia

I own a 1967, 400hp Tripower Corvette. I would be grateful if a fellow enthusiast can tell me the degrees advance my vacuum advance bottle should be. The one I have on the single point distribitor is a 24 degrees advance. At present the car has difficulty in idling under 1000 revs. My colleague thinks it might either be weak springs on the cams inside the distributer or a sticking/ worn vacuum advance bottle.

I would appreciate any advice that corvette enthusiasts have

Thank you

Vincent McGrath

[Joe L.]

Re: vacuum advance bottle on distributor

Vince-----

Well, this response is from California, USA which is a long way from Tasmania, Australia.

Your 1967 with L-68 engine is supposed to have vacuum control GM #1115360. This vacuum control produces a maximum of 6 DISTRIBUTOR DEGREES (12 CRANKSHAFT DEGREES) of advance at 12" of vacuum. If the vacuum control is original or an original Delco-manufactured replacement, there should be a stamping on the bottom surface of the vacuum control "arm" which says "360 12". This represents the last 3 digits of the vacuum control part number + the maximum crankshaft degrees of advance which it produces.

The GM #1115360 vacuum control is still available from GM and Delco, but it is no longer manufactured by GM or DELPHI and it no longer carries the described embossment. However, the current part is 100% functional in replacement of the originals and, except for the embossment, is configured very close to the original piece.

[Joe L.]

Addendum

I just checked and the 1115360 vacuum control has now been discontinued by GM. However, there should still be some around in dealer inventory. Also, this vacuum control is also sold in the aftermarket from manufacturers like Borg-Warner, Sorenson, and NAPA-Echlin (in fact, I believe the piece sold in the Delco boxes is EXACTLY the same as that which is supplied in boxes from these manufacturers).

[Duke W.]

Re: Addendum

NAPA/Echlin part number is VC1765, and it is marked "B20". Don't have the number for the other brands.

Duke

[Joe L.]

Re: Addendum

Duke-----

I think that NAPA may have some sort of error in their cross-referencing. I show the VC-1765 to be the equivalent of Delco # D1310C, currently aka GM #88924983. I can find no Corvette applications, at all, for this piece. I think that the NAPA/Echlin equivalent of the GM #1115360 aka Delco D-1383 is VC-680.