engine and drivetrain DCOE40 with Vacuum advance dist?

[69NEWCLASSNH]

Hey Guys,

   I've finally amassed all the parts I need to install my DCOE's this weekend.  I did overlook one huge detail.  My current 008 dist is vacuum advance..  Is there any way to get DCOE40s running on my car, without a TII distributor?  

 

I'd like to have everything together for the Bav Auto Show'N shine this weekend.   - Hoping I can figure out a way to do it with my current distributor.

 

thanks, 

  George

[KFunk]

It depends on the manifold you're using, and if there are any ports available.  You should at least have one for your brake booster, and maybe you have an extra one for the distributor too.

[69NEWCLASSNH]

2002TI manifolds..  I believe there is only one port for the booster... Could I run a T off of that?

[Simeon]

No is the simple answer. You can only get manifold vacuum from the manifold (funnily enough) but that vacuum advance capsule is set up for the ported, metered vacuum from just beside the throttle plate in the carb. 

 

You end up with full vac advance at idle that falls off as you open the throttle rather than no (or little) advance at idle that increases before dropping off as you come off idle. 

 

Run it with the vac disconnected and time it based upon maximum advance. 

[zinz]

32 minutes ago, Simeon said:

Run it with the vac disconnected and time it based upon maximum advance.

 

this...

 

Ed

[dlhoovler]

Just wondering, though it's not really germane to George's issue: With a 123 Tune distributor, can it be set up to use manifold vacuum, since it can ignore vacuum input below a certain RPM (e.g., at idle)? What would that vacuum advance profile look like--how different would it be from the standard-ish profile most people program in for ported vacuum?

 

-Dave

[Simeon]

2 hours ago, dlhoovler said:

Just wondering, though it's not really germane to George's issue: With a 123 Tune distributor, can it be set up to use manifold vacuum, since it can ignore vacuum input below a certain RPM (e.g., at idle)? What would that vacuum advance profile look like--how different would it be from the standard-ish profile most people program in for ported vacuum?

 

-Dave

 

Yes. It can be configured to react to whatever MAP pressure you present to it. The trick is getting a signal related to a single port runner or an average of the vacuum signals for each cylinder. The answer is it depends upon how accurate you need it to be. You can get a fitting that goes in a separate line teed off your brake booster line (before the one way valve) that delays the changes in vacuum (basically a restriction) to smooth out the pulses between the one cylinder and the rest. Alternately you can pick up individual runners and port them to a 'vacuum log' to get an average. I think a free people have done both. I think I would try the easy one first and see what you get.