Distributor Recurving?

[wjajr]

A comment on vacuum advance:

Vacuum advance is designed to improve fuel mileage of a street driven car during light throttle cruise conditions. The simple fact that the timing is fully advanced only during high vacuum running conditions, and retarded to initial + mechanical timing setting during low vacuum condition due to heavy acceleration does not impede optimal acceleration. As the vacuum increases and decreases while driving relative to acceleration rate or terrain conditions the timing added to initial + mechanical varies from zero to whatever the device is designed to add.

Most vacuum advance pods can be adjusted to come on in a range of vacuum levels enabling one to tune out any light throttle ping. There a selection of vacuum advance pods available to dial in anywhere between 6 degrees to 15 degrees, along with different activation levels based on vacuum strength, so someone can fine tune their curve to make an engine more efficient.

So to say “I ain’t hooken up the vacuum advance” on a street car makes no sense, because one is losing enhanced fuel efficiency.

 

[Snake]

A comment on vacuum advance:

Vacuum advance is designed to improve fuel mileage of a street driven car during light throttle cruise conditions. The simple fact that the timing is fully advanced only during high vacuum running conditions, and retarded to initial + mechanical timing setting during low vacuum condition due to heavy acceleration does not impede optimal acceleration. As the vacuum increases and decreases while driving relative to acceleration rate or terrain conditions the timing added to initial + mechanical varies from zero to whatever the device is designed to add.

Most vacuum advance pods can be adjusted to come on in a range of vacuum levels enabling one to tune out any light throttle ping. There a selection of vacuum advance pods available to dial in anywhere between 6 degrees to 15 degrees, along with different activation levels based on vacuum strength, so someone can fine tune their curve to make an engine more efficient.

So to say “I ain’t hooken up the vacuum advance” on a street car makes no sense, because one is losing enhanced fuel efficiency.

For ussss who likes foot to the floor most if not all of the time,we give too ***** about vacuum advance.If you don't want to go fast buy a 2 wheel bike.

 

[wjajr]

For ussss who likes foot to the floor most if not all of the time,we give too ***** about vacuum advance.

So you are drag racing only as that is the only driving condition I can think of that requires foot to the floor 100% of run time. All other driving utilizes variable throttle openings, and most of the time throttle openings are 90% closed. As I previously stated in tutorial, this is in regards to street driven vehicles.

I guess you still don’t understand vacuum advance. I’ll make it simple for the other readers, when foot is planted on floor there is no additional advance from vacuum actuated timing devices because there is no vacuum available to move the diaphragm. Additional advance over static and mechanical comes on at light throttle openings when engine is pulling high vacuum. This device won’t change acceleration abilities of your car, only save gas…

So how much is a liter of gasoline up your way these days?

If you don't want to go fast buy a 2 wheel bike.

When I don’t want to go fast I drive my Dart or ride with my wife in her heap, and when I do want to go fast I drive my computer controlled, variable displacement Hemi powered AWD 300 that gets 23 mpg on the highway.

Oh, thanks for the vote confidence in my ability’s by recommending two wheels with no mention of training wheels… LOL

 

[crackedback]

Vacuum advance can also cause issues with tuning/surging and promoting a lean condition if you aren't careful. Can it help with fuel economy, yes. I've had cars where the difference between with and without was less than 1 mpg. Worth the hassle, not to me. Depends on the build.

Then there is the whole manifold vs. ported vacuum source argument... Limiting total advance in the can if it's too much...

I don't generally put enough miles on my cars in a year to be concerned with the mileage difference, especially when the car requires a 50/50 or straight race gas for fuel.

Like anything, it takes work to get it right. Whether that effort is worth the benefit is solely up to the car owner.

 

[toolmanmike]

I took my 2 dual points apart. They both had a bar in them that was marked "RV" with a slot length of .375. I looked at the chart and elongated the slots to
.445 to give me 26*. My initial is 10* for a total of 36* so I'll see how that works.( Hopefully tomorrow if it doesn't rain all day). tmm

 

[toolmanmike]

I switched distributors this afternoon. My 273 idles best at 10° so I put the modified original back in. Mechanical advance was all in by about 2000 with a total of 35° I wish my vacuum was a newer unit and adjustable because the advance with the vacuum plugged in at 3000 rpm is in the upper 50's. I don't hear any ping on acceleration or at cruise. Did I mention how much better it
runs? A very noticeable difference. Much more powerful to 5 g's. tmm :toothy9::toothy9:

 

[67Dart273]

Very good. Sounds like you made some worthwhile progress.

 

[plumkrazee70]

Subscribed.

 

[highflyer]

This is a good read for guys [me ] who have done lots in life ,but not distributors[ nor third members]..thanks for taking a technical prob and making it sound simple and doable..thanks 67dart273 for the technical side of it in your part it explains lots...tx..j