vacuum advance c1

[Sander B.]

Hi can some one tell what the correct vacuum advance should be for a 230hp
1x4 carb

the one I have on the distributor does not give advance
it does not leak and works when i operate it manualy (with vacuum)

it looks like the advance is to strong or the vacuum to weak ???

the code on the advance says B22

can some one help me !! where i can find the right advance for my car ??

thanks you Sander, the Netherlands

[William C.]

Re: vacuum advance c1

what year?

[Jim T.]

Re: vacuum advance c1

From what little I know about vacuum advance units, the B22 indicates to me that this vacuum advance will advance the timing 22 degrees. My 70 has 20 stamped on the vacuum advance. Connect a vacuum guage to the vacuum line and see how much vacuum the engine is pulling. If there is no measurable vacuum increase the RPM's. If you get vacuum with the increased RPM's your vacuum line is connected to a ported vacuum source. Ported vacuum source does not provide vacuum at idle. It will when the carburator throttle blades are opened.

[William C.]

Re: vacuum advance c1

If we are looking at a '59-61 with a 1110946 distributor, the original unit would have been the 1116201, specs are 8 degrees (distributor, 16 crank) at 15-16 inches of vacuum. Very common unit on Chevy pass cars for many years, can stillbe found occasionally in junkyards (or at #14's place)

[Duke W.]

Re: vacuum advance c1

"B22" is an ID number for a vacuum can made by what was formerly Dana Controls that is now owned by Standard Motor Products. Any vacuum can with a two or three character alphanumeric code like "B1" or "B22" is Dana Controls (regardless of the "brand name" on the box) , and this number has NOTHING to do with the units performance.

The OE Delco manufactured vacuum cans had five digit ID numbers - the last three digits of the long GM number, a space, and then the maximum crankshaft advance.

Example: 201 16

Most currently available "Delco" cans have the Dana numbering system, since they buy them from Dana/Standard. If you get one with the old Delco ID system it's NOS because I don't think Delco has manufactured vacuum cans since the early nineties.

The "B22" vacuum can has the following basic specs in CRANKSHAFT degrees. Some spec sheets list DISTRIBUTOR degrees (half of crankshaft degrees) so BE SURE you understand specification context!

0 @ 7-9"
16 @ 14-16"

Assuming you have an engine with the base cam - 220, 230, and 250, 275 HP "low horse" FI engines, or a 250/300 HP 327, this can is well matched to manifold vacuum characterisitcs as long as the engine is in good condition and pulls at least 17" at idle.

The NAPA/Echlin part number is VC1802, and it costs about ten bucks.

Duke