Printable View
Just read great thread in modified section on where to get vaccum for vaccum advance canister on distibutor.
I ran out side and found my new(to me) 67 getting vaccum from port on head.
Where or how can I get my vaccum above carborator venturie on the stock 1bbl?
If you have a stock distributor/ignitor then there is no vaccuum advance. The vaccuum lines going to the distibutor housing are to remove any ozone that is created.
The only time you have a vaccum advance is if a Civvy distibutor has been installed.
oh yea, Wlecome to the zone and where are some pics of your truck?
oops forgot to say I have civy distributerQuote:
Originally Posted by Warthog
I think your reply helped the stock vaccume line has been run to the advance canister.Tomorrow I'llhave a chance to disconnect and try again. Thanks.
Here some pics of some of my junk.http://i561.photobucket.com/albums/s...nblood/023.jpg http://i561.photobucket.com/albums/s...nblood/027.jpg http://i561.photobucket.com/albums/s...d/HPIM2319.jpg
http://i561.photobucket.com/albums/s...d/HPIM2320.jpg
The location you are looking for is called a "ported vacuum port". The stock 1 barrel and the stock 2 barrels that came on the civvy motors as well as the stock 1 barrels that came on the mil engines had no provision for ported vacuum.
It might be possible to open up a ported vacuum port as was shown in the other thread for the 1 barrel but I cant really say if it is or isnt at the moment.
Why do you want ported vacuum? Get all the advance you can all the time.
If you google "vaccum advance" you will get all kinds of magazine articles about what is best. Ported or not ported. The basic science is that ported or non ported only really matters at idle and plate positons just above idle. Any other time the throttle plates are open, the vacuum above and below them is the same.
30% throttle open give the same vacuum above the plates as below. WOT give 0 vacuum above or below the plates as well. Until the pollution engines came along in the '70's, all vacuum advances were non ported. That was because at idle and partial light cruise, the timing was most advanced giving the engine better efficiency. I don't want to start a war over this either. Here was the first link my google search showed up:
http://www.highperformancepontiac.co...ech/index.html
It also does a real good job of explaining how either way can be made to work for you.
My 396 loves to have more timing. Yet, I pull heavy stuff with it in this insane heat around here. I can't go more than 9 degrees initial timing. Yet, with un ported vacuum advance and playing around with a few different cans, I have the thing 34 degrees advanced at idle. Super smooth and steady idle.
I have to move the initial up to 14 degrees to just get rid of severe lope with ported vacuum. Then it pings in granny gear trying to move in my drive way. Do it however you want, but try both ways before you settle on one.
That is great info...thanks for the education!!