Newbie with E3 welcome?

[Tierfreund]

Hi there,

I´m a longtime admirer of the E9. One of my first memories of cars is of my father having to sell my granddads silver 3.0CSI (blue velours inside) after he passed. I remember him showing of the toolbox. Lasting impressions.

I grew up on a very strange automotive diet with Mercs and Bimmers on my fathers side and plenty of Jaguars, Buicks, Pontiacs, Rovers, Cadilacs, Fords, Chevrolets, Corvettes, Lexus and a number of Opels on my other Grandfathers side. Strange because despite the heavy americana on the wheels, I´m from Germany.
My own automotive career has included Two VW Golfs, an Audi A3, two BMW E46C (the second most beautiful BMW coupe ever built, imho), a Mini Cooper an E90 and (so far) 3 BMW E3 (with a bettering rate of clean sheet metal to rust on each successive one).

I love driving. I´ve probably spent more time doing 155mph than romping and I still lust for an E9 more than (most) ...

yet, prices beeing as they are, and with all the pictures floating of what horrors await those curageous enough to strip an E9 to the metal, I´m currently sticking with the E3. The same incredible drivetrain, less of a bad conscience when driving sideways, and if you look at the front from far enough away, you can easily mistake it for a CS. Slightly less of the brown stuff even (though still plenty).
Currently I´m running a 71 3.0S in chamonix with triple webers and a fresh paintjob that allows me to think my car is solid.

So, how about it? Will you adopt me till I grow up and finally get myself a proper E9 motor?

I´ve been through the D-Jet and I´m deep into a triple Weber DCOE tuneup and I´ll be happy to share anything I´ve learnt.

 

[Honolulu]

Well heck yes

welcome aboard. Don't need to be an owner to participate here. Surely your triple weber experience will be valuable; and mechanically the E3 and E9 are very much alike.

 

[Arde]

3 * E3 = E3 * 3 = E(3 * 3) = E9

On the basis of simple arithmetic you are accepted.

 

[texcarguy]

Webers

Put me on your discovery list for the DCOE's... I have triple 40's on my E9, getting them reasonably close, but hungry for any information on perfecting my setup.

Welcome to the forum

 

[Tierfreund]

Just a little somthing I´ve learnt about the tripple weber.

1. Make sure everything else about your motor is first notch before you start fiddling with the carbs. Compression, valve clearances and ignition need to be first rate. The vacuum advance on the ignition doesn´t work with the triples, disconnect and leave open at the distributor. More static advance will do good (running 18 deg at 0 rpm, 20 at 1000 rpm and 38 deg at 4000)

2. Carbs need to be in great order. No play in shafts, all lines clear, good manifold all shafts exactly aligned.

3. Linkage: very important to have good linkage with minimum play and equal length arms. Goal is to get all carbs not only synched at idle but also opening absolutely synchronous.

4. fuel delivery: Low pressure but high volume pump required. Probably pressure regulator and in line filter required (the filters in the weber carb suck, take them out)

5. sizing and jetting. Less is most often more. 40s will usually be better for street use. There is a great little program (written for 4cylinder applications so divide your displacement by 6 and multiply with 4) that helps get venturi size an jetting pretty much spot on:

http://greend.com/jetting.exe

for my euro 3.0 stock compression (9:0), stock cam I´m running

3 x 40 DCOE with 34 chokes
mains: 140
air correctors: 180
emulsion tube: F9
Idle: 50 F9
pump Jets: 40

and that runs great. I´ve done the plug cutting at 2000, 3500 and 5500 and get all bambi brown plugs.

6. Idle set-up: All thats left is synching and setting the idle screws. For synchin I disconnet the linkage and synch with a simple tool called carbalancer. Works like a charm. For the idle mixture, the procedure of working by ear and optimizing revs per barrel doesn´t work too well on the M30. The M30 will run just fine on only 5 cylinders so you hardly notice how you´re doing on the mixture of one barrel. Much better method: I use a tool called colourtune which is a seethrough spark plug. You can see the flame while the car is idling and thereby can set the mixture just perfect per barrel while idling (thats all you can adjust anyway, as soon as you open the throttle your on the tubes anyway.

After setting idle mixture and idle synch I connect the linkage and make sure it now has no play while not altering the idle synch. Then I recheck the synch at different throttle opening.

Basically, the tripple weber is a great setup and hard to fault as long as you are really really thorough in initially setting it up. But then, once you´re done, it´ll last for ever and doesn´t really ever need readjusting.
It´s such a simple and reliable setup.

Most times the car runs poorly on tripples, the carbs are not at fault, but ignition, valves, linkages, fuel supply anything but the carbs is the reason. You can never ever make a car that runs poorly run better by simply adjusting the screws. These really only are for idle.

Anyone need a writeup for the plug cutting principle? The best thing short of a rolling road with lambda sensors for each barrel in the exchaust manifold for finding out what your mixture is.

 

[Honolulu]

very interesting

certainly your recipe for triple 40s will be added to my "info stash" though I'm unlikely to ever need it...

It seems you run greater ignition advance than I've heard correct... I thought 32 degrees was max... comment? Surely it has to do with the octane rating you're running.. .and everything else, but commonly I have read that 32 degrees was about the limit.

 

[Tierfreund]

The Dreikugelwannenbrennraum (or so...) allows up to 38-40 deg of advance with the 9:0 compression of the euro motor. I´m running euro fuels though with 95-98 octane.

I believe in stock euro config on the 3.0S and Si the distributor will reach 38 deg at about 4000rpm as well. Only less advance at idle and vacuum advance during part-throttle compared with my modified distributor.

Not quite sure what the octane ratings in the US are, but less would certainly mean less advance to avoid pinking.