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Dizzy question

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bugedd

bugedd

Jedi Knight
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The distributor in my car was apparently off a Cooper S, and has only a mechanical advance, no vacuum. Now, is there a performance advantage to one over the other? My car feels a bit lacking, which can be for several reasons. I just want to make sure this is not one of the reasons.
 
It is more for "bling" than anything else. In a full blown race car where the throttle is almost always open the then you are saving the weight of the vacuum stuff but the vacuum helps to give you a bit more torque upon stoplight acceleration and lessens "valve rattle" (by retarding the spark a bit).
Is that what you were asking?
BillM
 
Not that specifically, but that works :smile: I guess my motor seems a bit lacking, partially due to age, the Weber DGV which I hate, and other issues that may lie. I guess my question is do you get better performance with a dizzy that has a vacuum advance vs. mechanical only. Now, if the vacuum advance gives more "off the line" performance, then thats the way I want to go.
 
Ya, but I really like the look of a Weber DCOE. Call me crazy :smile:
 
Ya, but I really like the look of a Weber DCOE. Call me crazy :smile:
 
The vac advance aids in better economy by advancing ignition under light throttle. Mechanical advance doesn't sense load like a Vac does. Vehicles with a vac advance tend to have a bit quiter exhaust at highway speeds too. You need/can use more advance when vacuum is high, ie, cruise speeds when A/F ratio is leaner. I converted my 1500 from vac retard to vac advance w/ the DGV and dual SU's. I liked it. Now that I have a DCOE, I wish I could still hook it up, but I like this carb better. For me, it's simpler and more responsive. Plus, I can get to my manifold nuts and dip stick easier. You may find a vac advance might make your DGV smoother.

I'm getting about the same milage with all three, sucky! (~21-22 mpg)
 
well the dgv is going away, I just got a dcoe off ebay. so for what that is worth.
 
I really wish DCOE's had a vac advance port and a accelerator jet that misted instead of streamed. I wish I would have known you wanted one. I have an A series manifold and sidedraft Dellorto 40 I need to move.
 
As stated by some above, vacuum advance is for part throttle fuel economy. It does not come into play at wide open throttle and typically not much at idle. Still... you are supposed to disconnect and plug the vacuum tubing when setting the dynamic timing.

The 40819 dizzy you have would be fine for almost any 1275 A-series. It goes without saying that if you decide not to use it that there is a market for them. You will have no trouble selling it.
 
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