Crane Vacuum Timing Limiter

[Bill75]

I know this sounds a little stupid but I can't help myself!

I want to limit the amount of timing advance my HEI dist can is producing so I installed the Vacuum Timing Limiter Plate from Cranes adjustable vac advance kit. The instructions say that "each notch on the plate will shorten the amount of vacuum timing by 2 deg. It will also advance the initial timing by 2 deg because of the change in the starting position of the breaker plate or magnetic pickup."

So if I want my initial timing to be 12 deg and I have advanced the plate to limit the total by 4 deg (two notches)should I still set the initial timing to 12 or should it now be set to 16??

Bill

 

[BarryK]

you are referring to limiting the amount of vacuum advance you are getting?
if so, why use a "bandaid" fix like this limiter plate? Just install a new can that comes in at 2" HG below the vacuum level your motor produces at idle and that has the amount of advance that you want.

you can see a list of vacuum advance units in Lars paper here on my website's tech articles page:
http://lbfun.com/Corvette/Tech/vettetech.html

scroll down to the section titled *****Distributor & Timing**** and find the article called:
Vac Adv Spec.pdf
by Lars Grimsrud

on page 5 of the article is a listing of the various vacuum cans for HEI units. Don't confuse them with the units for points distributors that are listed above the HEI units

 

[Bill75]

you are referring to limiting the amount of vacuum advance you are getting?
if so, why use a "bandaid" fix like this limiter plate? Just install a new can that comes in at 2" HG below the vacuum level your motor produces at idle and that has the amount of advance that you want.

you can see a list of vacuum advance units in Lars paper here on my website's tech articles page:
http://lbfun.com/Corvette/Tech/vettetech.html

scroll down to the section titled *****Distributor & Timing**** and find the article called:
Vac Adv Spec.pdf
by Lars Grimsrud

on page 5 of the article is a listing of the various vacuum cans for HEI units. Don't confuse them with the units for points distributors that are listed above the HEI units

Yes I am. Why is this a band aid? What if I don't know the exact amount this motor needs , do I keep buying different cans until I get the one that works the best?

I thought this would be an easy way to dial it in. You don't think so??

 

[Bill75]

OK Barry...I read it over several times along with a few other articles I found on line. I see your point, Thanks!