Weber selection and initial jet tuning

[240260280]

btw are all tests run with air filters either in place or removed?  A partially restrictive air filter will have a choke effect and draw more fuel so if they are in place for one run but not for another, a change in AF may occur,

[blodi]

Put in 165's. I kept the 230 airs.  I'll report back tomorrow or Monday with a log.  The AFR is 20.9 when I first plug in the Innovate and the car has been sitting for a day or more. So, that tells me it should be calibrated? 

Yes, all air filters are on and have stayed on through all testing. They are also brand new and should still be really clean. 

[240260280]

Great.  Thanks for reporting the details, it helps to rule out variables.  

No worries about the free-air calibration. It should be close.

 

Still it is difficult to understand the cause of these occasional  strange jumps in behaviour. Why the recent run has the rise in the middle part of the run is baffling.  The larger air jet should have leaned the top end like the 238 but not as much. Maybe it is atmospherics as SweatyBetty suggested. I guess more testing is needed. It sure is iterative.

 

Hopefully the new E tubes on the way will have different shapes with no hump in the middle. We could be simply battling an"F16"... and not the type that flies.

Edited September 9, 2017 by 240260280

[blodi]

I agree...some odd results. I'm hoping one of the new e tubes flattens the curve. We've never been fully able to flatten it out other than when I put the 238 in. 

[blodi]

Tried to take logs yesterday....running into a new electrical issue all the sudden.  AFRs' looked good up until about 5K (usual lean bump then hovering around 12.-7-12.9) The butt dyno suggested power felt really good. Then at ~5K the engine starts sputtering and the ignition fuse blows and  the tach/center gauges all die.

So...gotta figure that all out now. 

[blodi]

Also, the other E Tubes showed up today!  But, until I get this electrical issue sorted...testing is gonna have to wait. 

 

[240260280]

Murphy's law.  Glad the e-tubes arrived.  We will have great data soon!  No need to rush... snow is still far away

[Duffman]

I have finally got my triples dialed in on my 70 Z with rebuilt L28, stock cam and flat top pistons.  

Thanks, Blodi, for posting your experience, it helped me a lot!  And a big thanks to 240260280 and Chickenman for all of their help over the last number of months, it helped make sense of these wonderful carbs!

Weber DCOE 40 151 current specs:

Venturis - 32 mm, auxiliary - 4.5 mm, float needle valve - 1.75 mm, idle jets - 50F9, main jets - 161 (drilled), air corrector jets - 200, pump jet - 50,                        pump exhaust - 00, emulsion tube - F16

I am running around 12.5 to 13.5 on acceleration, with 14.5 on highway cruise (with AFR gauge).  Idles very smooth at 850, but could go lower if I wasn't running AC.

Life is good ...

Edited September 12, 2017 by duffman
addition

[Patcon]

5 minutes ago, duffman said:

Life is good ...

How far above sea level?

[Duffman]

Phoenix, AZ, is about 1100 to 1200 ft above sea level.

Edited September 12, 2017 by duffman

[blodi]

Nice work duffman! I'd be curious how your afr curve looks. Do you have logging capability? 

Nice looking setup! 

[Duffman]

I don't have logging software to graph my results, unfortunately, but I did the same thing you did with consistent runs from 3000 to 5500 rpm on a flat road. I was getting solid readings on my gauge.


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