vacuum secondaries or mechanical

69bronco · 02-15-2006, 11:40 PM

hey what is better,vacuum secondaries or mechanical

Mr 5 0 · 02-16-2006, 05:34 PM

Unless you are running a big-block race engine, vacuum secondaries (using engine vacuum to pull the secondary throttle plate open) are the best way to go - which is why most aftermarket 'street' carbs are equipped with them. They are more practical for the street. However, 'bigger' carbs (750, 850 CFM) intended for big-block engines and/or race applications (usually with very high-lift cams) can be bought with mechanical secondaries if you need them.

Holley sells a secondary diaphragm spring kit that allows you to adjust the secondary opening rate, if you wish. In fact, Holley sells just about every part of their carbs except the body, a la carte. Again, check the Holley website for details.

Sorry, but I also posted this reply under your original thread in error.

I'm happy to answer your questions here (to the best of my knowledge) but I suggest you post these technical carb questions on the Windsor Power forum where they will receive a lot more views - and replies.

Capri306 · 02-16-2006, 10:35 PM

I second what Mr. 5.0 said, but especially the part about posting in the correct forum. Please read the sticky at the VERY TOP of the Blue Oval Lounge, and all will be clear. Thanks.

69bronco · 02-16-2006, 10:43 PM

srry about puting it in the wrong form

02-15-2006, 11:40 PM	#1
69bronco Registered Member Join Date: Jan 2006 Location: New Carlisle, IN Posts: 48	vacuum secondaries or mechanical hey what is better,vacuum secondaries or mechanical __________________ Jack 1969 Bronco, 351 cleveland 1972 Bronco, 351 Cleveland

02-16-2006, 05:34 PM	#2
Mr 5 0 Conservative Individualist Join Date: May 1997 Location: Wherever I need to be Posts: 7,487	Re: vacuum secondaries or mechanical Unless you are running a big-block race engine, vacuum secondaries (using engine vacuum to pull the secondary throttle plate open) are the best way to go - which is why most aftermarket 'street' carbs are equipped with them. They are more practical for the street. However, 'bigger' carbs (750, 850 CFM) intended for big-block engines and/or race applications (usually with very high-lift cams) can be bought with mechanical secondaries if you need them. Holley sells a secondary diaphragm spring kit that allows you to adjust the secondary opening rate, if you wish. In fact, Holley sells just about every part of their carbs except the body, a la carte. Again, check the Holley website for details. Sorry, but I also posted this reply under your original thread in error. I'm happy to answer your questions here (to the best of my knowledge) but I suggest you post these technical carb questions on the Windsor Power forum where they will receive a lot more views - and replies. __________________ 5.0 Mustang Owner 1990 - 2005

02-16-2006, 10:35 PM	#3
Capri306 Moderator Join Date: Sep 1998 Location: Grand Rapids, Michigan, USA Posts: 1,001	Re: vacuum secondaries or mechanical I second what Mr. 5.0 said, but especially the part about posting in the correct forum. Please read the sticky at the VERY TOP of the Blue Oval Lounge, and all will be clear. Thanks. __________________ Capri306, Moderator The Mustang Works Online 1979 Mercury Capri 1987 5.0L Mustang LX Notchback 1993 5.8L Eddie Bauer Bronco

02-16-2006, 10:43 PM	#4
69bronco Registered Member Join Date: Jan 2006 Location: New Carlisle, IN Posts: 48	Re: vacuum secondaries or mechanical srry about puting it in the wrong form __________________ Jack 1969 Bronco, 351 cleveland 1972 Bronco, 351 Cleveland

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