engine and drivetrain Carb decision time. Please help!

[mtriple]

I posted this earlier within someones thread and didnt get much luck. Any ideas or pointers would be greatly appreciated:

I am very very interested in a 32/36 aggressive setup per this post

http://www.bmw2002faq.com/component/option,com_forum/Itemid,50/page,viewtopic/t,291267/[\url]

as I have a dilemma now and need to make up my mind. Here is my story:

My engine is finaly broken in (2600 miles) properly. I was lucky to score a set of new euro tii raised bathtup pistons and I am running 9.8 compression according to the engine builder. Now I am at the point where I need to do something about my carb. The car is pretty quick even with the old non rebuilt one barrel solex. I am ready to tackle the carb and bare in mind that I might go with 292 cams down the line. My carb choices:

1) Rebuild the solex myself with the $30 kit and see what happens.

2) Have the solex rebuild at a carb shop.

3) Go with the OP setup here and get a 32/36 and make it work.

4) Weber 38/38?

5) Other setup (ala side draught)

The car will be for spirited driving and yes I'm in LA so stop and go traffic will be included.

Now that I saw this post I am tempted here..

hamada

[Guest Anonymous]

There have been many many posts on this subject that seem to go in all directions. You have to synthesize this information to fit YOUR anticipated needs. You mentioned spirited driving, and even that description is vague. Consider the working rpm range of your engine.

With a mild cam, it seems you are in a better position to take advantage of the greater airflow offered by the 38/38. (If someone could adapt the Zenith 36'ers that would be my first choice.) However, because of the greater performance "potential" the 38/38 would be my first choice. If you are concerned with the ultimate fuel economy, stick with the Solex. Respecting the 32/36, it is but a compromise. I have it on my non-injected car, and because it is a super high mileage, daily driver, I see no need to change to the larger carb when I have no intention or need to do any hot rodding. If, on the other hand, I had other performance aspirations, the larger would be my natural choice.

Recently, F1Reverb and ChuckS also contemplated similar choices. I have not followed either's stories, but maybe they will chime in with their experiences. In any event, since you have posted your question twice, and I have taken the time to respond, have the courtesy to post an update so others may profit from your experience.

[jerry]

bennet's comments are right on target.

i'd like to add to the discussion by relaying my brief experience with the single-barrel solex. for in-town driving it is zippy and provides plenty of punch. it may suffer from freeway driving when you desire a punch at the top end as it can only deliver so much fuel.

i remember talking to you at palo alto. your car is a nice unmolested example as-is. i'd leave it alone. it appears from your signature that you have an M3, if so, don't try to play catch-up with your 02. it's a whole different experience.

as for rebuilding the Solex, the key is determining whether the shafts are worn. if you don't have idling issues you are probably all right. if the shafts are worn there's not much you can do other than trying work-arounds like i'm gonna do. i've installed a rubber grommet to try to cover the air leak past the shaft. the grommet actually is compressed against the housing to try to squeeze the gap shut. installing a rebuild kit is pretty straight forward.

your car is a nice example of how they came off the boat. those examples are becoming harder to find and when they are found, their values tend to be higher than the 'modded' examples.

[Mike Self]

not the unlamented 2 bbl one.

As has been pointed out, so long as the throttle shaft isn't worn (and mine is still tight at 218k) they're a snap to rebuild--it'll take you about an hour, and 45 minutes of that will be soaking it in a can of carb cleaner.

For a daily driver, the Solex is fine--you can always install a larger main jet and air correction jet to take advantage of the higher compression, and can even install a larger venturi. Solexes are at least as tuneable as Webers.

As for a 32-36 Weber, they can be made semi progressive pretty easily--not quite a 38/38, but better than a stock 32-36, where the second barrel doesn't start opening until the primary barrel is nearly full open.

If it were my car? I'd rebuild the Solex and see how you like it. Play with the jetting a little (there's a formula for determining jet sizes). If you're still not happy, then contemplate a Weber...

cheers

mike

[TTyMiller]

This is my standard reply when one of us asks about a carb upgrade below 40's

http://terrysaytherauto.com/2002Weber.htm

[mtriple]

Thank you all for the great insight. I picked up a carb rebuild kit along with a couple of carb cleaner spray cans. I already took off the carb. The journey begins.

Bennet: Thanks for the reply. I took many pics and I will post them up when I'm done.

Jerry: it was nice meeting you at Palo Alto. I agree with you. I do plan to keep it unmolested. I shouldn't try to play catch up with the M (its blown btw ) I love the simplicity and true driving experience this little car brings. As a matter of fact I hardly drive the m3 now.

Mike: I am indeed going with the same carb. Nothing to lose. A lot to gain.

TTyMille: I will take this route if my carb fails.

Does anyone have any pointers while I tackle this ?

TIA

hamada

[mtriple]

Great news:

I went on and rebuilt the solex 1 bbl carb on Saturday and it took me a couple of hours. It was my first time EVER to go that far with a Carb. I am glad I did. After taking it apart along with 100 pics for each step I made, I soaked that bad boy in Carb dip for an hour. Cleaned up every little nook and hole with carb spray and then compressed air.

What I noticed was the bottom part of the carb (the throttle shaft area) LOOKED NEW! it looked newer than the rest of the car body. No play at all. The float looked new as well and I didn't do much, but replace the gaskets and one Jet.

I have been playing with the idle mixture/idle settings and I think I finally got her where I want.

Thank you all for the help and I will keep her this way until the carb explodes into pieces!.

hamada

[mtriple]

One more thing I JUST noticed was the float setting. All what I did was install the float back EXACTLY like it was. No measurment whatsoever. The car is running fine, but I want to know if I need to take that cover off and do something?