engine and drivetrain Dual 40Webbers The (Close To)Final Dial-In

[ndog]

i have tested my car with the redline instructions as far as idle speed screw 1/4 to 1/2 open,idle mixture screw 1 turn out from lightseating, I can get the car dialed in from thier,,,,, adjusting only the lead barrel on each carb,then adjusting the 2nd barrel after. my jets are 125mains,55f8 idle on a korman 300 cam....................... buuuutttt why is my a/f ratio 13.5 ish  at idle and at wot its not going down it stays @ 13.........(not even close to 12 or 11.5)

sorry if this is a encrypted question I speak better than type.

thanks all

 

 

 

emo tube is f16

chokes 33

pumpjet 40

bleed 55

aux vent 4.5

Edited May 8, 2013 by ndog

[Hans]

are these new Webers with the air correction locking bolt (in addition to air needle valve)? 

[ndog]

they are old and idont think have that lock deal

Edited May 8, 2013 by ndog

[MrForce]

An AFR of 13:1 is close to ideal for WOT, probably better than 12 or 11.5 for a naturally aspirated engine. How do your plugs look? As always AFR numbers are guidelines and plugs and performance are the best measuring sticks.

 

Rob

[Hans]

they are old and idont think have that lock deal

Then your initial set-up is fine. Make sure the rubber O-rings are under the cups on the mixture screws

[Harv]

I was thinking the AFR's sounded fine too. Might even be able to clean up the idle a bit.

John

[TobyB]

You don't mention your air correctors.

 

If you want it to go (a little bit) richer as revs rise (over 4500, probably)

go down a size on the main air correctors.

 

13:1 is great, if you're paying a little bit of attention to it occasionally.

 

If you want a safety margin, you can drop to 12.5:1 at WOT at 6000 and 

it won't kill power enough to be noticable.  It will hurt your lap times slightly.

 

But I agree- this seems just about freakin' perfect for power.

 

hth

 

t

[LimeySteve]

Nate , what you have is the recipe from the Weber book with a slightly larger main (the book has 120 mains ) now the fuel we get has ethenol in it which is shit to burn so the jetting will need to be different , I suspect the book was written when we had proper gasoline. You could try the next size up main & see if that yields a fatter number at WOT, then get the idle down to 14-15 on your o2 sensor , jobs a good one. Also have you balanced them at idle ?, that is critical .

[ndog]

thanks all,sounds like Iam close I will verify with the plugs and check the orings on the covers are okay..steve, i tried the hose in the barrel/venturi  trick However my ears are slightly shot from surfing...

I placed the gauge on the dash and Iam obsessed with watching it TOO much maybee....

Edited May 8, 2013 by ndog

[LimeySteve]

I did the same thing , obsessed with the gauge , once I was set with my numbers it only gets an occasional  glance now.Bring it to my shop Saturday & I can put my gauge on it & set the balance if you like .

Edited May 8, 2013 by LimeySteve

[mossyboy6]

Where do you live?

[ndog]

steve .thank you sir I hope to see you sat... I can always spend time gawking at the crazy stuff you build...

[ndog]

thank you limey steve for your help... I was glad to see the pre-install bench tests i did worked..........awesome stuff you do at your shop sir

[LimeySteve]

I'm glad I could confirm your dial in & balance, give some tips & have a nice chat , also it sounds like your trip home was a blast ,nice to see what MPG you get , remember I'm running 45's so with those nice 40's you should see some good numbers , even if the loud pedal gets a pounding.

[M3M3]

mid-upper 12's are the optimum power range.  idle at 14+ is good....cruise should be 15's.

Edited May 12, 2013 by mlytle