914/6 Webers + vacuum advance

[914timo]

Hi All !

I have a '71 914 6 conversion with 3.0 liter '79 911 SC engine. The engine has Solex cams and triple Webers. The distributor is original with the vacuum advance system.

My question is now should I use the vacuum advance or not ? If I should use it, where should I take the vacuum from ? The carbs has no place for vacuum pipes. Should I make one in the inlet manifold ?

It runs without the vacuum advance, but if I take it in use, will it run better ? Is it worth of it ?

Any comments, advises, suggestions ??

Timo

[maf 914]

Timo,

This topic has been discussed at length in the Shoptalkforums.com, Type 4rum. There have been several threads with one currently under discussion. Check it out and do a search for past threads. One point is that the vacuum source is not manifold vacuum but vacuum from above the carb throttle butterfly.

Mike

The current Type 4rum thread is here: http://shoptalkforums.com/bbs/NonCGI/Forum1/HTML/001967.html

[Otto]

There is a difference between ported vacuum and manifold vacuum pressure. One vacuum is above the throttle butterfly and one is below. The vacuum for the 3.0 is not ported therefore it is used for vacuum retard, not vacuum advance. Some years came with both vacuum advance and vacuum retard. 81 to 83. OTTO

[J P Stein]

Ah....expert help.

Otto:

I recently purchased a new RS distributor ( or what is passing for one, these days) for my 2.7L......Solex cams, Webers & stuff....and have noticed that it has vacuum advance (retard?).

There is a port on my PMO manifolds and it is(obiviously) below the butterflies.


The motor runs well with the 2.4L T dizzy (no Vacumm set up).

Recommendatons?

[Otto]

What is the part # on the dist.??? I'll go get one and see what you have, retard or advance. OTTO

[J P Stein]

Part # 0 231 184 004

TIA for the help.

[J P Stein]

Otto:

I wuz lookin' for a receipt in my folder when something fell out on the floor. Hey, look at that, a receipt from Otto's.......hey, LOOK at that receipt from Otto's.

Being as it's from 1998, I think we can call it "water under the bridge".

I'm sending you a copy off list.....this is just so you know where it came from.

Humm....I thought I was sending you a copy. Can't do it from the Pelican site. You got an address?

[Otto]

707 S Hampton Dr. Venice, CA. 90291 OTTO

[J P Stein]

Sorry, I should have been more clear. I meant an email address.
I went to your web site and then sent it to "Sales".

[Otto]

That part number of that dist. is for a 1974 Carrera. OTTO

[J P Stein]

Humm....don't like the sound of that....unless it's a Euro Carrera.
It came with 7300 rpm rev limiter rotor.