Vacuum Advance suppliers

[Duke W.]

Re: Vacuum Advance suppliers

The VAC is worth 3 total judging points - two for originality and one for condition, and not all the JGs specify the number, and you can't always read the number with the distributor cap installed.

So it's better to have a VAC that is functionally matched to the engine, but not all OE VACs are so matched, such as the "201-15" on the '63 340 HP engine.

If I know that a VAC is a B-number replacement, I take one point for "OE replacement" regardless of whether the B-number spec is equivalent to OE, and if I know the B-number replacement is not a good match for the engine's vacuum characterisitcs, I verbally inform the owner and state which B-number is the best match.

At a recent chapter judging event we had a very original '65 L-79 with about 60K miles that had been in a warehouse for about 20 years. It has the original 236-16 VAC, but it had a lot of visible rust on the housing, so it lost the condition point.

The owner plans to replace this OE VAC with a B20 or B26, which is better matched to the vacuum characteristics of the L-79 than the B28 equivalent to the 236-16.

A properly matched VAC is critical to proper engine operation, so IMO it's more important to have a properly functioning and properly matched VAC even if one (out of 4500) judging point has to be sacrificed to do so.

Duke

[Cliff K.]

Re: Vacuum Advance suppliers

Update on B-28 vacuum advance. I was able to place an order online with GMpartsgiant.com. However, I received a cancellation notice from them this morning stating the part is no longer available. I currently do not know of a 'supply house' that has any available.

I have had a couple of offers from some generous and selfless fellow members and have been able to secure one. I thank the members of the NCRS who have been so helpful. It is great to be able to share knowledge.
Thank you
Cliff

[Joe L.]

Re: Vacuum Advance suppliers

Update on B-28 vacuum advance. I was able to place an order online with GMpartsgiant.com. However, I received a cancellation notice from them this morning stating the part is no longer available. I currently do not know of a 'supply house' that has any available.

I have had a couple of offers from some generous and selfless fellow members and have been able to secure one. I thank the members of the NCRS who have been so helpful. It is great to be able to share knowledge.
Thank you
Cliff

Cliff-----

It never ceases to amaze me that folks often scoff at aftermarket replacement parts (like these Standard Motor Products manufactured vacuum controls). But, when they are discontinued, they become quite precious.

[Michael M.]

Re: Vacuum Advance suppliers

Update on B-28 vacuum advance. I was able to place an order online with GMpartsgiant.com. However, I received a cancellation notice from them this morning stating the part is no longer available. I currently do not know of a 'supply house' that has any available.

I have had a couple of offers from some generous and selfless fellow members and have been able to secure one. I thank the members of the NCRS who have been so helpful. It is great to be able to share knowledge.
Thank you
Cliff

Hi Cliff,

I'm glad you were able to find one. Hopefully, it functions properly. I got my B26 from Rock Auto (if I remember correctly), but they didn't have a B28 when I looked last night. I couldn't even find the B26 there until a local parts guy gave me a cross reference # (DV1808) for the Airtex/Wells brand. Not sure who makes that brand, but it works perfectly and looks right too. Good luck and have fun.

Mike

[Duke W.]

Re: Vacuum Advance suppliers

Cliff-----

It never ceases to amaze me that folks often scoff at aftermarket replacement parts (like these Standard Motor Products manufactured vacuum controls). But, when they are discontinued, they become quite precious.

I think some guys still think that if you buy a "Delco" part they're actually getting an original made by GM part. We know that GM has not manufactured most of these ignition system parts since back in the early nineties when they started spinning off the manufacturing divisions.

As I've said many times before, Delco is now just a marketing outfit, and the ignition products they sell as "Delco" are the same SMP-manufactured part that you find inside nearly all other brand boxes.

And most of the engine parts that you can still get from GM for vintage engines are manufactured by Federal Mogul and Dana Corp., and these same parts are available at usually lower prices in F-M and Dana's own brands like Sealed Power and Clevite.

Duke

[John D.]

Re: Vacuum Advance suppliers

Not all B28 vacuum advances are created equal you know.
I agree with Joe Lucia. The B28 is a generic part with one manufacturer with different labels. Or should I said it WAS a generic part.
Personally if I had a driver I would prefer a nice used grunchy looking 201 instead of a local auto store part.
Or I would prefer a 1st class reproduction that has been tested and right on the money.

The writing is on the wall NCRS members.
The way things are going one can expect to see less and less antique distributor parts,etc being made available at the big name chain stores.

[Cliff K.]

Re: Vacuum Advance suppliers

My final outcome. Even though I was able to order a VAC from Chicago Corvette for High Performance, what I received was a B-1 vacuum advance, which is what I already had. The B-28 is simply not available from any "commercial" outlet that I could locate. A very generous and trusting fellow member was able to furnish me with one. It made the engine run like it was meant to be and, as importantly, it now runs cool. So the fellowship of Corvette enthusiasts comes through again. I thank everyone for their input and assistance.
Cliff

[John D.]

Re: Vacuum Advance suppliers

Cliff, I had a huge stock of B1 vacuum advances. Bought them from Chevy in the old days. Probably the most worthless VA to come down the pike. The spring on them is soooo strong.
I gave most of them to my son and he put them on his junk table at the Carlisle tables and sold them for peanuts.
Trouble is the box they came is had a part number that was a service replacement for a 63. (I think it did. Started off with 163.......)
Glad you got the B28 Cliff. John

[Duke W.]

Re: Vacuum Advance suppliers

Cliff, I had a huge stock of B1 vacuum advances. Bought them from Chevy in the old days. Probably the most worthless VA to come down the pike. The spring on them is soooo strong.
I gave most of them to my son and he put them on his junk table at the Carlisle tables and sold them for peanuts.
Trouble is the box they came is had a part number that was a service replacement for a 63. (I think it did. Started off with 163.......)
Glad you got the B28 Cliff. John

A 201 won't work properly with any OE mechanical lifter cam other than the '63 FI because it was a one year only ported vacuum advance setup. They figured it out for '64 and used a 8" VAC with both mechanical lifter cam engines including FI, which got full time vacuum advance.

I fought idle stability and stalling problems with my 340 HP engilne until I figured out that the Duntov cam didn't pull enough vacuum to pull the 201-15 VAC to the limit and keep it there at idle.

Once I installed the '64 236-16 VAC, I had no more idle stability/stalling problems. GM screwed up the vacuum advance engineering in '63 for both the SHP and FI engine. This was the first time vacuum advance was used on mechanical lifter engines. They figured it out and fixed it for '64, but '63 owners were left in the lurch to figure it out and fix it on their own.

Somebody screwed up when consolidating part numbers and the 163 (B1) was substitued for the 201. So one error was compounded by another. The 163/B1 is a boat anchor. It takes 18-19" to pull it to the limit, so it doesnt' even meet the Two-Inch Rule for a base engine.

This happens more than you think, and the aftermarket picks up on the new number. Then it's cast in concrete and will never change. This is especially true for VACs since few people understand the whys and wherefores and how to select a VAC for a specific engine configuration even though it's no more complicated than fourth grade arithmetic.

Duke

[Wayne M.]

Re: Vacuum Advance suppliers

......Somebody screwed up when consolidating part numbers and the 163 (B1) was substitued for the 201. So one error was compounded by another. The 163/B1 is a boat anchor. It takes 18-19" to pull it to the limit, so it doesnt' even meet the Two-Inch Rule for a base engine. ......

Duke --- is this the '163' culprit ? [first thumbnail]. It shows in my Delco 1956 thru 1963 supplement test specs book as 1116163, along with the '201' (1116201).

I see what you mean with that high vacuum requirement; the '163 spec says 8 to 10" Hg to start advance; and 16.25 to 18" Hg for max. advance (8 deg distr = 16 deg crank, as stamped on the can).

And the '201 is not much better (per Delco spec book): 7-9" to start, 15 to 15.75" for max advance; also 8 deg max advance (distr. degrees) which is stamped 15 (close enough) on the can.

Aside (to all) while we're on the subject of vacuum. I just booked a flight from the ice fields of Alberta to glorious sunny California for a week in January, to coincide with the Pomona swap meet. Where can I buy a new Mityvac, to check all the cans I have ?

[Duke W.]

Re: Vacuum Advance suppliers

Yeah, that's the bad guy. I'm not aware that it was OE on any Corvette engine. The 201 is okay for a base engine with manual trans, and the current B22 is very close in spec. I recommend the 12" B20/B26 for base engines with autos. It's the same spec as the 355, which was OE on '66-'67 base engines, so it would be compatible with both manuals and PG.

Duke

[Joe R.]

Re: Vacuum Advance suppliers

Aside (to all) while we're on the subject of vacuum. I just booked a flight from the ice fields of Alberta to glorious sunny California for a week in January, to coincide with the Pomona swap meet. Where can I buy a new Mityvac, to check all the cans I have ?

Wayne,

I see that Harbor Freight has them:

http://www.harborfreight.com/mityvac...ump-39522.html

Joe

[John D.]

Re: Vacuum Advance suppliers

I drive by the Standard Motor Products HQ building in Long Island City, NY all the time. It's a massive place but it looks like they only use a part of it now. I suspect they've off-shored most of their manufacturing.

[Cliff K.]

Re: Vacuum Advance suppliers

UPDATE
Rockauto.com now has a new supply marketed under the brand name of Airtex Vehicle Electronics (Airtex/Wells), Part Number is 4V1053, Vacuum Chamber. Even has B-28 stamped on it. I ordered two and they both tested 3 to 8 inches of vacuum from start to all in. Cost was $5.72 each plus s&h.
Cliff Kennedy

[Michael M.]

Re: Vacuum Advance suppliers

UPDATE
Rockauto.com now has a new supply marketed under the brand name of Airtex Vehicle Electronics (Airtex/Wells), Part Number is 4V1053, Vacuum Chamber. Even has B-28 stamped on it. I ordered two and they both tested 3 to 8 inches of vacuum from start to all in. Cost was $5.72 each plus s&h.
Cliff Kennedy

Hi Cliff,

Glad you were able to track them down. You got off cheap too, the B26 (4V1006 or DV1808) was almost twice the price at $9.07 But it works perfectly and is made in the USA! Shocking.

Mike