E9 DCOE 38 Jetting??

[andyleonard]

I've unearthed a set of 3 DCOE38s, probably off half of a 12 cylinder 4 liter from the 70's. They came with 30 chokes, 140 mains - F41 - 190 air. Idle jets are 45 F23. The idle air bleed screws are inset in a little tunnel and were sealed with nylon plugs...and were all at different settings ranging from 1 3/4 out to 3 1/2. Smog? EPA import?

I have a stash of idle jets, airs and mains...and a set of jet drills I'm not afraid to use... but I'm told that chokes are hard to get and might have to be turned down from 40s. In any case, I have no larger chokes for these carbs so I guess I'm stuck with the 30s..

I was thinking about putting them on a stock 3 liter motor just for fun and to sort the linkage, etc., while we're cooking a 3.5 with some better parts. And I have my doubts about using them on a larger motor with compression, cam and headers.

Question: The chokes seem a little small, even for a stock motor, the idles seem lean and the air/mains seem way rich.

Comments please. What would a baseline jetting for a stock 3.0 with 3 DCOE40s look like?

 

[Stevehose]

32-34mm chokes, 135-140 mains, 180-190 air correctors, 50/55 f9/f8 idles, 35-40 accel pump jets would be my suggestion to start with. And an AFR meter!

 

[andyleonard]

Hmm. Sounds like with a little more idle jet it might run as-is. Pump jets are 35 now. Being stuck with 30 chokes might change things a little but hey...

Interesting that this is HALF of the carbs off a 4 liter and it's going more-or-less correctly on a 3 liter.

I don't go anywhere without an AFR. What did we ever do without them? Remember high speed plug cuts?

 

[Stevehose]

I think 30's will be too small, will likely cause your mains to come in too soon and possibly not allow proper air flow at the higher rev's

 

[andyleonard]

I think 30's will be too small, will likely cause your mains to come in too soon and possibly not allow proper air flow at the higher rev's

That was my first thought and why I posted. But I already have the carbs, there don't seem to be any bigger chokes around without firing up the lathe...and I have a 2002 at 10-1 with a cam and headers running Dellorto 40s choked at 30 which is running OK... plus the subject car is an automatic. So I figured it was worth a try unless someone had tried it and vetoed it, hoping the low end would be OK and that it rarely will see top revs anyway.

But the 38s probably won't make the cut with the new bigger motor. Bummer. Maybe if I add 3 more...