Thanks Duke...

[john pickens]

and all the true experts on the board . I took Duke's frequent advice to upgrade my C2 327 roadster to the Napa vacuum can, and replumbed it directly
to manifold vacuum. What a difference! Perfect idle, better driveability
for under 20 bucks. I highly recommend the conversion. As always, thanks for
a great resource.

[Duke W.]

Re: Thanks Duke...

You're welcome, but I'm curious - what engine option do you have? Modified? As far as I know all C2s have full time vacuum advance except for '66 and 67 models with CA emissions, all L-72, and maybe all L-71 and all L-78 (never have gotten enough data on these configurations to figure out one way or another.)

Also, what vacuum can part number did you install. There are three NAPA/Echlin numbers that should be suitable for most OE and modified engines with max vacuum advance at 8, 12, and 16". You chose whichever one is at least 2" higher than your normal idle speed vacuum with about 25 degrees total idle timing.

Duke

[john pickens]

Re: Thanks Duke...

I installed the NapaEchlin VC1810 as you had mentioned in previous posts.
The cannister which I replaced has numbers MS 360 12 engraved into the base
plate. I have no idea if it is original, but was stiff as a board when I removed it and checked the plunger. As for the advance, my rebuilt Holley came
on the car- has list 2818 and is a 4150-appears to be consistent with the 1965 supplement diagrams. The hose to the vacuum can originally ran from the passenger side of the carb in front of the choke-I assumed this meant that the vacuum is "ported"
by definition. Am I wrong in that assumption? At any rate I now have full time vacuum advance, a new cannister, smooth idle at 700 rpm on startup, and significant low to mid speed drivability improvement.Even a blind squirrel
finds an acorn now and then...

[Duke W.]

Re: Thanks Duke...

So am I correct in assuming your engine is a L-79. Don't know about the configuration of your installed carb, but you can verify if the port that the vacuum line was on is full vacuum by checking it with a vacuum gage.

The "360" can is not original to L-79, but was used on the '66 L-36/72. The Delco "236" can was used on L-79 and the VC1810 has the same specs. All the old Delco cans have a five digit codes - the last three digits of the part number followed by the maximum crankshaft advance. I don't know the the "MS" means.

It sounds like the can you took off is basically inoperative. It should pull to the limit at 12".

Duke