Vacuum or Mechanical Distro
Thread Starter
Instructor
Joined: Apr 2010
Posts: 177
Likes: 0
From: Fairview PA
Vacuum or Mechanical Distro
Question, any one have any good info on if a mechanical or vacuum advance is a better choice? Are they both about the same as far as accuracy?
Reason is I am considering swapping mine out with a mech unit with a MSD ignition. Currently have the L46 350hp with the stock distro and a pertronix module with a 45k coil.
Thoughts anyone?
Reason is I am considering swapping mine out with a mech unit with a MSD ignition. Currently have the L46 350hp with the stock distro and a pertronix module with a 45k coil.
Thoughts anyone?
Drifting
Joined: Dec 2002
Posts: 1,946
Likes: 28
From: Long Beach CA
He's right. All distributors have a mechanical advance, and a street-driven car also needs a vacuum advance connected to manifold vacuum. You can gain some performance by getting both advances "adjusted" to your engine's needs. Distributor tuning is a bit of a lost art, but there are still some shops around that do it. If you want to learn more about distributors, contact Lars on this forum.
Thread Starter
Instructor
Joined: Apr 2010
Posts: 177
Likes: 0
From: Fairview PA
Ok. Thanks... Few more questions then.
Do you think that if I were to use my stock dirstro with the pertronix kit I could still do something like the pertronix second strike electronic ignition? And if so... Worth it? I heard that it will help level idle? I put in a more aggressive cam (that would still work with the vacuum system in these vettes). Also these have the built in rev limiters...
http://www.pertronix.com/prod/ig/strike/default.aspx
The hard part is my car has not been started for the first time yet. So, not sure what to expect....
Do you think that if I were to use my stock dirstro with the pertronix kit I could still do something like the pertronix second strike electronic ignition? And if so... Worth it? I heard that it will help level idle? I put in a more aggressive cam (that would still work with the vacuum system in these vettes). Also these have the built in rev limiters...
http://www.pertronix.com/prod/ig/strike/default.aspx
The hard part is my car has not been started for the first time yet. So, not sure what to expect....
Melting Slicks
Joined: Sep 2004
Posts: 2,655
Likes: 19
Unless you're carbon fowling plugs, your standard points setup will work fine. Most engines will improve performance with more initial timing and faster advance. That can help idle too. To do that, all you need is a $10 distributor recuve kit.
Race Director
Joined: Jul 2001
Posts: 15,892
Likes: 42
Ok. Thanks... Few more questions then.
Do you think that if I were to use my stock dirstro with the pertronix kit I could still do something like the pertronix second strike electronic ignition? And if so... Worth it? I heard that it will help level idle? I put in a more aggressive cam (that would still work with the vacuum system in these vettes). Also these have the built in rev limiters...
http://www.pertronix.com/prod/ig/strike/default.aspx
The hard part is my car has not been started for the first time yet. So, not sure what to expect....
Do you think that if I were to use my stock dirstro with the pertronix kit I could still do something like the pertronix second strike electronic ignition? And if so... Worth it? I heard that it will help level idle? I put in a more aggressive cam (that would still work with the vacuum system in these vettes). Also these have the built in rev limiters...
http://www.pertronix.com/prod/ig/strike/default.aspx
The hard part is my car has not been started for the first time yet. So, not sure what to expect....
Tech Contributor
Joined: Aug 1999
Posts: 14,377
Likes: 6,377
From: At my Bar drinking and wrenching in Lafayette Colorado
Send me an e-mail request for my timing and vacuum advance tech papers and you'll get a pretty good understanding of the systems and their tuning parameters.
Multi-spark systems can help improve idle quality on a big-cammed engines, but there is little to be gained on near-stock engines. Total power output on mild street engines is not affected, since the systems stop multi-firing at 3000 - 3500 rpm.
Lars
V8FastCars@msn.com
Multi-spark systems can help improve idle quality on a big-cammed engines, but there is little to be gained on near-stock engines. Total power output on mild street engines is not affected, since the systems stop multi-firing at 3000 - 3500 rpm.
Lars
V8FastCars@msn.com
Race Director
Joined: Nov 2002
Posts: 12,142
Likes: 54
From: Taylor Michigan
If your interested in an electronic system if its a 75 or newer you have as good as it gets in the current HEI ignition...the only difference is money and bragging rights.....And you also have very good suggestions already posted whatever direction you proceed in
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