Selecting The Best VAC for My Engine

[Richard M.]

Re: Selecting The Best VAC for My Engine

For some reason, NAPA no longer stocks the B28, their Echlin Part# VC1810

But after some searching, in addition to the Airtex 4V1053, it appears the B28 is also available from Wells, Part# DV1810.

A quick search shows it is available from Autozone....

https://www.autozone.com/external-en...tor/118067_0_0

The Wells website has the min/max specification data.....

http://www.wellsve.com/custom_searches/pdf/sales_drawings/DV1810A.pdf

(also attached below if the link disappears in the future)

While there I also located the equivalent to the B26/B20, Echlin VC1765. The Wells equivalent is the DV1808. I used the "Search Competitor Interchange" -> VC1765 to find it. However, the datasheet for this part does not show min max values.

Rich

[Dan D.]

Re: Selecting The Best VAC for My Engine

Rich, you did better than I did researching this. This is good info and I expect other members will benefit from it. Interesting, the PDF drawing has a date of 1983. They did this a long time ago.

-Dan-

[Duke W.]

Re: Selecting The Best VAC for My Engine

I have #1 pointing right under the window.

I have no idea what you mean by the above statement. In my last post I was talking about how the plug wires are oriented on the cap. If you look directly at the cap window, #1 wire MUST be in the terminal immediately to the left of the window.

Duke

[Dan D.]

Re: Selecting The Best VAC for My Engine

I didn't say it right Duke. I have the #1 wire right above the widow. Not below. I see why that confused you. I will re-clock the distributor one notch to the left. That will move the gear and rotor 27.7* (360/13). The wire position on the cap will be moved 45*. So it sounds like I will have to turn the gear 180*, as you have alluded too. We'll see. Sound good?

-Dan-

[Duke W.]

Re: Selecting The Best VAC for My Engine

For some reason, NAPA no longer stocks the B28, their Echlin Part# VC1810

But after some searching, in addition to the Airtex 4V1053, it appears the B28 is also available from Wells, Part# DV1810.

A quick search shows it is available from Autozone....

https://www.autozone.com/external-en...tor/118067_0_0

The Wells website has the min/max specification data.....

http://www.wellsve.com/custom_searches/pdf/sales_drawings/DV1810A.pdf

(also attached below if the link disappears in the future)

While there I also located the equivalent to the B26/B20, Echlin VC1765. The Wells equivalent is the DV1808. I used the "Search Competitor Interchange" -> VC1765 to find it. However, the datasheet for this part does not show min max values.

Rich

Good work, Rich. As you may know all the "Bxx" VACs are manufactured by Standard Motor Products, but they are sold under a number of different brand names, including "Delco" via different marketing channels.

It's my understanding that SMP quit producing the B28 several years ago. It was a fairly low volume part because it was only OE on 350, 365, and 375 HP 327s, which were low volume, and since Echlin and Delco are more commonly know brand names for ignition replacement parts than Airtex and Wells, the former brands are long out of stock.

I recently purchased a B26 as a birthday gift for a buddy who just earned a Duntov award at this summer's national for his L-71. So now that that's over we can optimize the engine tune starting with converting the ported vacuum advance to full time, which requires replacing the OE 201 15 VAC with the B26 in order to pass the Two-Inch Rule.

I checked the start and stop points, which were in spec at about 6" and 12", and we'll check the max vacuum advance of nominally 16 degrees on the engine. It was a "Standard" brand, which is SMP's internal corporate brand. My neighbor across the street bought it for me on her Amazon Prime account for about ten bucks, so shipping was free.

The above are two of the three available VACs that are the best fit of all full time vacuum advance engines and ported advance converted to full time where the OE VAC does not pass the Two-Inch Rule. The third is the B22, start @ 8", 16 @ 15".

BTW there's something wrong with that Wells drawing pdf you attached. I says the B28 replaces the OE 1973449/D1390A. These sound like HEI VAC numbers that are physically different than the single point/TI VACs, and they are not interchangeable. The OE GM number for B28 is 1116236. It looks like Wells uses the same numbers as NAPA/Echlin with just a different alpha prefix, which should make it easy to find a Wells number if you know the NAPA/Echlin number. Just change the VC prefix to DV.

So hopefully they'll be around for awhile, but don't spread the word to far afield.

Duke

[Mark E.]

Re: Selecting The Best VAC for My Engine

If NCRS judging isn't a concern, consider a variable VAC. It allows you to dial in the specific vacuum advance that makes your engine run best.

[Dan D.]

Re: Selecting The Best VAC for My Engine

Good news. Just got my new vacuum canister from Rock Auto. Starts a 4*; all in at 8*. Perfect. The box says "WVE Vehicle Electronics".

It is stamped B28. Sticker on it says "Made in Mexico". I'll take care of that little problem.

I am not going to be home tomorrow, but should be able to install it and re-clock the distributor Saturday. Will let you guys know the results. You guys sure are a life saver.

-Dan-