engine and drivetrain Sidedrafts Tuning for POWER!

[MaTiaS]

are you sure you have 38's...for dcoe 40's? i thought the biggest size made for dcoe 40's was 36..... 38 is a dcoe 45 size.

Yes, Im pretty sure there were. They were definitely bigger than the 36s that came with it. Right now Im waiting for an order I did on a set of 34s so whenever they arrive Ill swap them and I''ll recheck the numbers to make sure.

[M3M3]

are you sure you have 38's...for dcoe 40's? i thought the biggest size made for dcoe 40's was 36..... 38 is a dcoe 45 size.

Yes, Im pretty sure there were. They were definitely bigger than the 36s that came with it. Right now Im waiting for an order I did on a set of 34s so whenever they arrive Ill swap them and I''ll recheck the numbers to make sure.

available sizes of chokes for dcoe's...

dcoe 40 24-36

dcoe 45 28-40

[TobyB]

+1 a36 choke is already wafer- thin for a 40.

t

[Lee]

Back in the days, I remember it was very common for fellow racers to rebore their choke. Possibly that's how a 36mm unit can become a 38mm. But I agree that there's not much material left.

My suggestion to Matias is to go back to a 32mm choke and enjoy. Power is good. But torque and drivability are better...

[boxy02]

"But I would still measure every port and passage if I bought a new one. "

Toby, which passages and how did you measure them? What tools are required for this? I have calipers. Geez, I hope I don't have the crappy Spanish 40's!

[MaTiaS]

I took them off today and did not find a number in them, but they are really thin. Anyways, the venturies arrived today, unfortunately the 34s we ordered were bigger than the holes of the carbs, I think they might have sent me 34s for a 45dcoe instead. However the 32s were the right size so we went ahead and swap them. we changed the main jets to 130s the idles to 55f8 emulsion tube f16 aux venturies remained the same at 4.5 and acc jet also unchanged at 40. Car runs excellent, I can easily cruise between 1500 and 2500 rpms with a quick throttle response... now the fun starts above 2500 rpms, the transition of fuel/air from the idle jets to the mains is so smooth that my curve of power does not suffer any lag at all. The car pulls very fast all the way up to redline and more. I think we got it just right and matched the pick of the curve with the cam to keep the hp going and going. What my mechanic will try to do this weekend is to change the acceleration and air correction jets a number up or number down to see if it makes the entire setup even better ;D

[Lee]

The idle jets will greatly affect the transition up to 2500RPM. I suggest you increase the size of the idle jets

Lee

[TobyB]

Huh- with 32 chokes,, 55's seem about right for transition jetting.

But that's the joy of the DCOE- it's so easy to try other things to

see if you get an improvement. You might!

Toby, which passages and how did you measure them? What tools are required for this? I have calipers. Geez, I hope I don't have the crappy Spanish 40's!

What I found was that one of the borings that was supposed to line up with

the gap in the threads on the main jet holder was drilled so low that it came out

beneath the threads. I THINK that lead to the air corrector

being completely bypassed, but this was a while back.

I also found that the 'shelves' that are milled into the body were off by

mm...

A pair of digital calipers was adequate- it helped a lot to have another body sitting next to it to compare.

t

[MaTiaS]

when do the accelerator jets come to the equation? if I swap them would I feel a noticeable change?