engine and drivetrain cold hard truth on dual carbs

[nbristow01]

Ok guys, I need the truth here. I am planning on buying carbs this jan. I am very torn. I love the look and sound of dual 40s but all I seem to read about is how much trouble they are. Are they really that much trouble? i drive my car to work several times a week and don't mind resynching carbs on the weekend once in a while. it seems i read that it is just misery from day 1 dealing with the dual but dang they look and sound good. Or should I sucxk it up, shut up, buy a 38/38, shut the hood and find something else to obsess about

My engine is bone stock but putting a complete msd ignition setup on right after christmas

[RandyMolson]

I put on a used set of dual sidedrafts and have not had a stitch of trouble. In fact, they are more troublefree than the standard Weber carb that I had before. The water choke on the previous carb never worked a damn. My sidedrafts dutifully start up regardless of condition, run like a top and do not stall at idle. They are manual choke, but I really don't use the choke at all. I did have to put on a tii brake booster for fitment, and I fabricated some linkage from bike parts and such. It took a few tries to design the right linkage. The only negative about my sidedrafts is they throw off a ferocious engine odor for a while, so I have to park my 02 in the driveway a few hours before bringing it into my attached garage. Thats a bit of a pain actually, but their power and dependability are worth it.

[Guest Anonymous]

Ok guys, I need the truth here. I am planning on buying carbs this jan. I am very torn. I love the look and sound of dual 40s but all I seem to read about is how much trouble they are. Are they really that much trouble? i drive my car to work several times a week and don't mind resynching carbs on the weekend once in a while. it seems i read that it is just misery from day 1 dealing with the dual but dang they look and sound good. Or should I sucxk it up, shut up, buy a 38/38, shut the hood and find something else to obsess about

My engine is bone stock but putting a complete msd ignition setup on right after christmas

Define trouble? Is your engine high strung and finicky? Does it fall out of tune every Weds? or when the sun sets?

I am sure some people find checking valve lash as trouble. Same with gapping plugs. If basic carb theory is difficult for you to grasp and setting up and tweaking carbs a nightmare then buy the downdraft. Resynchronizing carbs on the weekends is no big deal nor should it be necessary unless the carbs are prone to significant wear and rough handling. Once any carb is properly jetted and adjusted for your engine it shouldn't require constant attention other than cleaning and lubricating.

Do you have to readjust the timing every odd weekend? If so, opt for an electronic ignition and run away from all carburetors except the single barrel downdraft.

[nbristow01]

Thanks Marco, I understand both carb and engine basics well enough to keep things running. That was not my question. Just curious if all I am reading is actually due to the design of the carb and not the owner.

[jrhone]

Let me jump in...I bought a modified engine for my 02...I had a weber 32/36 in the car before and it wasnt in the best of shape. So I had a decision. Buy a 38/38 or buy a dual side draft setup. My heart wanted the duals soooo bad....but EVERY shop and even some extremely reputable race shops that sell tons of 02 parts...(cough...Ireland) said that the performance advantage of the side drafts really only kicks in at high RPMs. For the street its overkill. This is on a modified engine. On a stock engine you may LOSE low end power. Then there is the tuning. Probably requires a bit more upkeep...but not a huge amount. The shop that did the engine install that does work on all kinds of BMWs only and the owner who has lots of amazing cars incuding a few super modded 02s said NOT to get the duals...he said I would be happy with the look and sound, not happy with a frequent bill to keep them running properly. I got the 38/38...but still to this day lust after the dual 40s and just may do it one day. I just know I will be in for more upkeep. Now what I think I will actually do is EFI with ITB's....all the look...and no downside...

[allbim]

Let me jump in...I bought a modified engine for my 02...I had a weber 32/36 in the car before and it wasnt in the best of shape. So I had a decision. Buy a 38/38 or buy a dual side draft setup. My heart wanted the duals soooo bad....but EVERY shop and even some extremely reputable race shops that sell tons of 02 parts...(cough...Ireland) said that the performance advantage of the side drafts really only kicks in at high RPMs. For the street its overkill. This is on a modified engine. On a stock engine you may LOSE low end power. Then there is the tuning. Probably requires a bit more upkeep...but not a huge amount. The shop that did the engine install that does work on all kinds of BMWs only and the owner who has lots of amazing cars incuding a few super modded 02s said NOT to get the duals...he said I would be happy with the look and sound, not happy with a frequent bill to keep them running properly. I got the 38/38...but still to this day lust after the dual 40s and just may do it one day. I just know I will be in for more upkeep. Now what I think I will actually do is EFI with ITB's....all the look...and no downside...

I don't know about "no downside". I can tell you from experience that there is an extremely helpless feeling that comes over you when your computerized engine stalls or fails to start. A feeling that you would never get with an engine that uses caburetors and points to make it run. This is from a guy who understands FI and electronics pretty well.

[jrhone]

I don't know about "no downside". I can tell you from experience that there is an extremely helpless feeling that comes over you when your computerized engine stalls or fails to start. A feeling that you would never get with an engine that uses caburetors and points to make it run. This is from a guy who understands FI and electronics pretty well.

true!

[c.d.iesel]

forget / don't waste yer money on that ignition thing

go for the Duel-DCOE's - it's what your heart wants,

and include at least 3 books about webers

and READ!!! - and become comfortable in

your new WEBER skin

p.s. frigget the 38/38 idea -

[Fishhead]

forget / don't waste yer money on that ignition thing

go for the Duel-DCOE's - it's what your heart wants,

and include at least 3 books about webers

and READ!!! - and become comfortable in

your new WEBER skin

p.s. frigget the 38/38 idea -

One book I highly reccomend is "Weber carb tuning and theory" by John Pasanni.

I bougth this book when I put dual DCOE40's on my Honda CB 750 SOHC. I have had the Webers on my SOHC for about 4 yrs. and they have "required" no tuning since then ("fiddling" with them is almost manditory, but not needed- kinda like a kid with a new toy that never grows old- LOL).

Get the Weber dual 40's and get the Pasanni book. The Passani book really opened my eyes to how carbs work and the theories can also be used on other carbs.

Fishhead

[Paul7002]

MSD isn't going to change the fact that the engine is otherwise "bone stock" as you say. Side drafts are probably going to be over kill. The 38/38 is a good choice and actually, for a truely stock motor, the 32/36 is not a bad choice either.

[TEAEYE]

It's your car do what your gut feels.

On both Tilux that I once had (and still miss) I had Weber 45 sidedrafts and the second car I had was a low miles creampuff with the original Solex 40's, I never had carb related problems at any point on either car.

I would not hesitate or feel cautious based on not being familiar with them. If you are buying brand new carbs I would expect no problems at all.

Synchronisation I recall being a fun thing to do and should not be viewed as a chore. I used to check mine about every 6 months, but very seldom did I realy ever have to realy adjust them realy that much, looking back It was more on me than either brand of carb!

I see some of the points others bring up that if the stock motor and carb are acting fine why mess with it if you are not sure or have not driven with sidedrafts.

That happened to me with my last 2000, the car had a low miles factory rebuild in it with the stock downdraft and it just ran too nice, I missed the roar of the Ti's I had earlier and realy thought about it for awhile but kept putting it off because the car had terminal rust in the shock mounts when I bought it. Some cars you should only do so much with.

I later sold that motor to a guy with an 02 and the guy called me up weeks later to tell me just how happy he was!

Not to steer you one way or the other but I realy loved on a cold day pulling the choke and giving the sidedrafts that little blip of the gas pedal to get them going!!!

If your car is solid and you want to knock yourself out I say go for it!

[MarkDavis]

I ran a set of 40mm Mikuni's on my last 02 for about two years before I was rear ended and I only had to adjust the jetting twice. When I installed them in the summer and then once more for the winter. I had a high milage stock moter in the car and the side drafts just brought the car to life. It was a huge improvement. I am getting ready to install a set of Mikuni's on my current 02.

Mark

[Squatch Pads]

Are side drafts over kill for a stock motor? Probably. Are they fun? Heck yeah. The sound alone is worth it. The roar that comes from under the bonnet when accelerating is awesome. I hear a lot of people complain about their side drafts not being reliable. Most of the time they are not set up properly to begin with. They are reliable.

As with many other threads on this board about opinons sought, it's your car. Do what you want to. Your driving it and you my friend have to be the one happy.

Good luck on your decision.

[bcthomas122279]

The sound alone is worth it. The roar that comes from under the bonnet when accelerating is awesome.

X2

Spine tingling!

[kenkoy214]

Bump ! I just had a valve job and getting tempted to put on my dual 40DCOE which I bought long time ago. Can I just put this on a stock E12 head motor.