do you guys know if the VC-1810 will work on an MSD dist ?
I have the pro billet 8361 and I only have 6-7" vac @ idle in park !:confused:

Trev, do it. What ever fits, use it. Just installing vacuum advance will raise your idle readings and your engine will like it.

Just installing vacuum advance will raise your idle readings and your engine will like it.
Dont work that way....put a unit in thats not in the corrct vac range and ends up surging in idle or no difference at all
Or wrong deg range and have pistons still coming up when fires, loading pistons rods bearings, exhaust valves burn while happly cruising down the highway not even awear the engine is killing itself.

I only have 6-7" vac @ idle in park !

Assuming the cent curve is correct once the car is moving...at idle advance the intial up till just get a reasonable idle...not a factory smooth, just a sign its smoothing out sightly....(note big cams big carbs run very ineffiently at low rpms..idle hence why the rought idle low vac)
This advance will be between about 10 deg and 16 deg depending on your engine.
Note the vac.When you are establishing the idle advance you need to do so in gear (auto) and readjust the idle speed and mixtures to establish the correct vac you are aiming for in the VA.
There are 2 schools of thought
1/ you need a VA that is all in about 1" below this vac
2/you need a Va thats the same or about 1 to 2 " above.
I prefer the latter..as advance increases so does the vac at a constant rpm...the VA starts pulling after firing up, advances which holds in...
The All in vac should be in the ball park of the engine vac on the highway, about 60 mph cruising up a gentle slope...which will also be very close the the idle vac you need.

you have currently an idle vac of 6 to 7" at say 10 deg intial ..you find say 15 deg is what u want....and vac is 13 "
The highway vac up a gentle hill is 14" /15" (this is the piont you need to retard under load) so the VA will need to be all in around the 13 to 14.5" and will need 15 minus 10=5 degs in the VA

this also gives u an extra 5 deg in the advance for lean light load cruise on the highway
So if you cruise at 2600 rpms and the cent is all in 34 deg at 3200 rpms at 2600 rpms instead of cruise being about 27 deg cent it will be 32 deg.

Foot note..you have to have the cent curve plted out for your engine before setting up the VA.

Yup works just fine.. Did that swap about 2 months ago.. If you do a search on here you will see that it mentions a B-29 cannister...The 1810 is that same cannister and has the B-29 stamped on it.

Yup works just fine.. Did that swap about 2 months ago.. If you do a search on here you will see that it mentions a B-29 cannister...The 1810 is that same cannister and has the B-29 stamped on it.

Nope. The VC-1810 can is stamped "B28".

:beers:

If you want to limit/extend vac and/or deg range, it doesnt take much to lengthen the slot and/or make up little tags likepic below I made up, at each end.
There are adjustable VAs avalabe but even then not always adjustable in the range you want for older cars...And a 2nd type where if you push real hard inside the whole internal turns to give 6 adjustable ranges
http://kakariki.net/camaro/dizzyAdjustVA.jpg

John I have been meaning to ask you for a long time now
ZHow is it that the numbers stamped on VA units like VC-1810 and b-28 have what I see as no relationship to the part #s in the Ac Delco service manual specs like
model # 1115360 and spec #3955
This random unit has
6-8" to start
11.3 to 12.5 for max advance
6.4 +/- 1 deg max advance (dizzy degree not crank)

mistified me for yrs

John I have been meaning to ask you for a long time now
ZHow is it that the numbers stamped on VA units like VC-1810 and b-28 have what I see as no relationship to the part #s in the Ac Delco service manual specs like
model # 1115360 and spec #3955
This random unit has
6-8" to start
11.3 to 12.5 for max advance
6.4 +/- 1 deg max advance (dizzy degree not crank)

mistified me for yrs

Because the VAC units stamped with the "B-numbers" are all aftermarket parts, made by Echlin, Dana, and now by Standard (Standard bought the Echlin and Dana VAC businesses three years ago). Original GM VAC's were stamped with a 3-digit number followed by a 2-digit number (last 3 digits of the Delco part number, and the number of degrees advance at max pull).

Current GM and AC-Delco VACs are "B"-numbered, as they're Standard parts, re-boxed by AC-Delco under the GM and AC-Delco part numbers. Delco hasn't made them for over 25 years, and AC-Delco doesn't manufacture anything any more, and hasn't for at least ten years - they're strictly a parts marketing organization.

:beers: