Carb set-up

[Barnfind]

Looks like a complete day job..

But surely it's worth it..

Now I have another problem, called "Take the complete lump out, strip it down in pieces, spend a fortune in it, and put it back toghether"

I'll open a new thread as soon as I have the pictures on this computer..

Thanks for the help..

[Stefan2000]

Does someone know what type of emulsion tube should be in an early 2000 40DCN 14 carburettor?
Just want to be sure that i have the correct original one in place before i go to the dyno. Right now i have a F33 tube, but can't find any information about what tube should be in there originally.

[Stefan2000]

Allright,

Today i went to the dyno, so this might be valuable information for fellow dino owners. But maybe in particular (or only) dino 2000 drivers with the 40 DCN 14 carburettors.
My assumptions where right and it was indeed running lean at transition. Really not only at transition but the whole rpm range was on the lean side.
I was running around AFR 15:1 at idle circuit, around 14:1 at main ciruit and around 18:1 at transition. 14.7 is Lambda 1 so most fuel economic but for best performance the aim is around 12,5:1

Then i first changed my main jets from 130 to 135. Now it was running main circuit between 12 and 13:1 so quite acceptable.
Then i changed my idle jets from 55 to 60's. That made me running on idle circuit at around 13:1 so also quite acceptable.
They were funny enought the exact sizes that i bought because i assumed that i would be pretty close and it was indeed. The only thing i still need to change is the air correctors from my current 185's to 170's because at higher rpm it's leaning out a bit to much. The guy did not have 170 correctors in stock so we did some tests and made some calculation and were sure that with 170's were almost spot on.

So the question now is, did i get rid of the flat spot. Yes, it's definitaly 98% good right now, i still notice 'something' but it's really really minor and not annoying and i guess it is pretty much as good as a carburettor can be.

Now for our fellow dino drivers the current carburettor setup:

Original: Mains - 130 / Idles - 55 / Air correctors - 180 / Emulsion tubes - F33
Improved/current: Mains - 135 / Idles - 60 / Air correctors - 170 / Emulsion tubes - F33


Was not really interested in the amount of horsepower but just to get rid of the flat spot but in the end it did put out 158.8 HP. So it lost 1.2 HP in 47 years which is not a bad thing i quess The guy from the dyno put my maximum ignition advance to 35 degrees because in his opinion the Original 40 degees was to dangerous. I kind of disagreed with him but we made the runs with 35 degrees maximum. So i'm quite confident that with the right air correctors and the 40 degrees ignition advance i will exceed the original specifications... which says something about the engine's health i guess. It has some 15Nm of torque more than the specifications quote allready.
As a funny coincident he previously had 2 more dino 2000's on his dyno so we could compare graphs. My car was pulling 14.6 and 16.7 HP more than the other 2 dino's

HP and AFR before and after

Green line - my car compared to 2 other dino's

And a movie:

https://www.youtube.com/watch?v=SC0bA_v ... e=youtu.be

[doublegarage]

Stefan

wow that's great info - thanks for posting - sounds like your Dino is really healthy. And it certainly sounds healthy from about 1:05 onwards in the youtube video.

Thanks again
-Richard

[Stefan2000]

Yes i'm very happy with the results.
It was a pain in the *** to get everything right but it did pay off.
I think i disassembled the carburettors about 30 times to get it spot on, most off all the float levels.
I installed new needles and set everything to factory specifications (float hight of 47,5mm) and it was pouring fuel into all the throats through the secondary venturies. Then i took out the emulsion tubes, made adjustments to the float, fired up the engine every time and looked at the real float level with running engine. After a couple times level was okay but then i figured out that my fuel pump was only only providing 0.15 Bar of fuel pressure and 80 liters per hour (not the original fuel pump). Than i replaced the pump for a 110L/H and 0.35Bar. Again fuel pouring into the throads, another 15 attempts to get the float hights in real life within 0.5mm. I ended up with a float hight varying between 50 and 52mm measured at the float to the carburettor cover as stated in the manual to get everyting even while running.
So i don't know exactly why but just putting all floats even like stated in the manual does not guarantee an even float level in the carburettors. Probably it was when everything was new but it might be worth double checking in general when setting things up.

I assume my AFR graph will be somewhat similar to cars fitted with DCNF. Or at least the changes in AFR compared to jet size. This means that changing a main jet with about 0.05mm will shift your AFR with about 1:1 on main circuit (see red line compared to blue line in graph)
Idle jets had a bit more influence on the AFR, for a change of 0.05mm about 2:1 (not shown in graph because graph is only at wide open throttle, but determined during normal everyday driving test on the dyno while measuring AFR)
Might be a good thing to know for people trying to experiment with jet sizes.

[Jos_2400]

Great post Stefan!! Will bring my 2400 soon to get it fine-tuned!
And yes; should arrange a 3 car transporter!!!!!

[Barnfind]

I might end up fitting bungs and caps to my new exhausts to have them ready to fit widebands..

Good job, thanks for sharing..