I purchased a distributor with a vacuum can B22 and am wondering if someone on the board can post specs for this can. Thanks in advance, Tim Barbieri
vacuum can
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Re: vacuum can
Duke,
Is that the same map as this one:
MS
355 15
This is from a 67 base engine distributor. Would the B2 be a replacement.
Jerry Fuccillo
#42179Attached FilesJerry Fuccillo
1967 327/300 Convertible since 1968- Top
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Re: vacuum can
Jerry-----
I have the replacement for the GM #1115355 as "B20". NAPA/Echlin part number should be VC 1765. Also, you should be able to get this part under GM #88924983 or Delco D1310C.
Specs are
16 maximum crankshaft degrees @ 11-13 inches vacuum
5-7 inches of vacuum to start the plunger
By the way, the GM #1115355 vacuum control is among those reproduced by Paragon. although I couldn't say that they're 100% correct in the "eyes of all". Cost is about $45.In Appreciation of John Hinckley- Top
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Vacuum advance control VAC
No, the 355 16 is a 12" VAC (16@12"). They are better suited to a base engine w/PG because PG idles at lower revs and vacuum in Drive than a manual in neutral, and because of the PG issue a 12" VAC was used on all '66-'67 300 HP base engines. A more aggressive than necessary VAC can cause transient detonation when you add throttle. This is a more critical issue now than when these cars were built because of today's lower octane premium fuels.
If your 300HP/manual trans configuration does not exhibit any transient detonation with a 12" VAC there is no need to change to a 15" VAC, but if one needs a new VAC for a 300 HP/manual and cannot find an origial Delco version with the correct OE ID, my recommendation is to go with a 15" aftermarket VAC, ID B22.
The following (max advance spec and ID number) are what I recommend as replacements for all C1/C2 engines based on typical idle vacuum - aggressive enough, but not too aggressive, so some may be different than OE. Note that there are only THREE, which are well matched to ALL OE engine configurations of this era.
16@15" (B22) - all base engines or base cam engines with manual trans, Special 300 HP cam with manual trans (Typical idle vacuum over 16" to 19")
16@12"(B20 or B26) - all base engines or base cam engines w/PG, L-79, all big block (Idle vacuum range over 13" to 16") (Note 1)
16@8" (B28) - all small blocks with mechanical lifter cams (Idle vacuum range 10-13") (Note 2)
Note 1: Convert all L-72 and L-71 from ported to full time vacuum advance
Note 2: Convert '63 FI engine from ported to full time vacuum advance.
Searching the archives for the above listed ID numbers will yield at least one manufacturer's part number, and you can cross reference these to other manufacturer's part numbers at their online cross refereance catalogs.
Duke- Top
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