Good source for the B28 (8 mmHg) VAC

[Michael L.]

Guys,

I'm changing out the VAC on my distributor to adhere to the "2 inch rule". I researched online and found an article that Duke wrote with a couple of co-authors that details the possible sources for these, but I've struck out on everything that was listed except for the RockAuto part number WMA 4V1053. I ordered that but when it came it doesn't have the B28 designation. I haven't had a chance yet to test it with my MightyVac to see if it specs out to a B28 but in the meantime I'm wondering if anyone has a source for these with the B28 marking. Thanks for any help.

Mike

[Duke W.]

Re: Good source for the B28 (8 mmHg) VAC

There's been at least one report on the Corvette Fourm that this Rock Auto WMA 4V1053 is not a B28. What is the B-number that you received, and what are the "Hg start and stop points?

You can do the community a big service by contacting Rock Auto and informing them of the problem.

I don't know of any other sources other than what a current Web search reveals, and I think this Rock Auto part is all that's left.

Standard Motor Products stopped manufacturing the B28 some years ago.

Duke

[Michael L.]

Re: Good source for the B28 (8 mmHg) VAC

Duke,

There is no B# on the VAC from RA. See the attached pics. Part number on it appears to be 20210628

I will reach out to RA to let them know it's not good once I have a chance to test it. I'm not terribly concerned with the appearance I'm more focused right now on getting the car running correctly.

Mike

VAC.jpgVAC box.jpg

[Dan A.]

Re: Good source for the B28 (8 mmHg) VAC

I have a new in box Airtex 4V1053 I bought a few years ago and it has B28 stamped on it. I actually bought two and installed the other one on my 72 LT-1 and it runs well. Out of curiosity I’ll check the new one I have this afternoon with my Mighty Vac and see what it does.

[Michael L.]

Re: Good source for the B28 (8 mmHg) VAC

FYI I found a B28 VAC at Volunteer Vette. I'll still check the one I got from RA just to see.

[Duke W.]

Re: Good source for the B28 (8 mmHg) VAC

I've never seen that part number or heard of WVE. Maybe they are buying VACs from some other source than SMP and having them stamped with their own part number. The B28 (Airtex 4V1053 and many other brands including Delco) is equivalent to the OE 1116236 VAC that was used on 365/375 HP engines, so it was a low volume part. Nominal specs are Start @ 4", 16 crank deg. @ 8"


What are the start and stop points. BTW that would be inches Hg not mm Hg.

Duke

[Bill B.]

Re: Good source for the B28 (8 mmHg) VAC

I had purchased my B28 can from Rock Auto back in Oct 2020 under "WVE 4V1053". It was stamped "B28" and can attest attaining max VAC advance with my idle manifold VAC of 10". I paid $13.28 at the time. Their website now lists it for $5.63, however, it does not show "B28" stamped on it.

Classic Industries sells one under P/N "DV1810" for $24.99

[Michael L.]

Re: Good source for the B28 (8 mmHg) VAC

I tested the VAC I got from Rock Auto under the WVE 4V1053 part number with my Mityvac. It's a little imprecise because I'm going by eyeball but it doesn't appear to move until 8mmHg and doesn't max out until almost 20mmHg. I will contact Rock Auto and let them know it's not a B28, in appearance or performance.

Mike

[Duke W.]

Re: Good source for the B28 (8 mmHg) VAC

Sounds like a B1 that won't pass the Two-Inch Rule for even a base engine, but it's called out in a lot of parts books for many engines due to an ill-conceived parts consolidation decades ago by GM. They sweat the details. Right!

Duke

[James W.]

Re: Good source for the B28 (8 mmHg) VAC

I had a B1 vacuum cannister on my 1965 Corvette L79 and it ran like crap. In Duke's own words "it's paper weight or boat anchor, get rid of it and install a B26" which I sourced through NAPA p/n VC1765 in March of 2019. The car now runs excellent.

In my parts stash, I have a brand new WVE/AIRTEX/WELLS B28 p/n 4V1053 that I purchased from Rock Auto in October of 2019. It is stamped B28. If you can't find one, it's yours if you want it.

James

[Douglas C.]

Re: Good source for the B28 (8 mmHg) VAC

I've always had good luck with NAPA, Echlin is the part for ignition. NAPA VC1810 should be a match to B28. It should also be stamped B28. Always bench test specs with a Mityvac.
Doug

[Duke W.]

Re: Good source for the B28 (8 mmHg) VAC

Standard Motor Products stopped manufacturing the B28 VAC several years ago. Slowly, but surely they began to disappear from the half a dozen or more brand names that they were sold under.

Going back at least a couple of years ago, Airtex was the last remaining stock, but it may now be dried up.

Duke

[Michael L.]

Re: Good source for the B28 (8 mmHg) VAC

Sorry guys correction. The VAC I got from Rock Auto starts to move about 6mmHg and tops out at 16mmHg. The numbers I listed previously are for the B1 that was on the car. So it's a little better but not by much.

Mike

[Michael L.]

Re: Good source for the B28 (8 mmHg) VAC

I had a B1 vacuum cannister on my 1965 Corvette L79 and it ran like crap. In Duke's own words "it's paper weight or boat anchor, get rid of it and install a B26" which I sourced through NAPA p/n VC1765 in March of 2019. The car now runs excellent.

In my parts stash, I have a brand new WVE/AIRTEX/WELLS B28 p/n 4V1053 that I purchased from Rock Auto in October of 2019. It is stamped B28. If you can't find one, it's yours if you want it.

James

Thanks James. I was able to order what is supposed to be a "B28" from Volunteer Vette so I should be good. Will let you know if it's not as advertised.

Mike

[Duke W.]

Re: Good source for the B28 (8 mmHg) VAC

Sorry guys correction. The VAC I got from Rock Auto starts to move about 6mmHg and tops out at 16mmHg. The numbers I listed previously are for the B1 that was on the car. So it's a little better but not by much.

Mike

That's INCHES of Mercury, not millimeters. Remember that a few years ago JPL lost a BILLION dollar Mars mission because someone forgot to transfer English to Metric (or maybe it was vice versa) for a course correction maneuver calculation.

Duke