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wirihana wirihana is offline
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Join Date: Mar 2003
Location: napier, new zealand
Posts: 29
2.4L dyno and carb jetting question

Hi all, a question from a frequent lurker, occasional poster

The engine in question is a 2.4 with 2.2S pistons and E cams with apx 4k miles on it. It runs strong, pulls hard on the throttle with no flat spots but has been 'weak' at cruise. More throttle pushes you through this easily, but you can't accelerate all the time! An in-car narrow band O2 sensor showed it was running rich, so I went and organised a dyno to establish a baseline and get more accurate A/F readings.





results as follows:





Do the HP and Torque graphs indicate a healthy engine? - I think they are about right, and the A/F curve seems to be o.k. (just on the richer side of stoich.)

However, when we ran the car at very light load/cruise from apx 2500-4000 RPM, it read very rich - staying between 9-10 A/F ratio. We could look at the results on the computer screen as it ran, but could not record it to post here.

How can i tune these carbs to run leaner at cruise while retaining the WOT (or near to it) power?

The carbs do not spit, pop, and it idles very cleanly. It has a yellowish tinge around the exhaust on the bumber. It has PMO's with the following jets

idles 57
mains 120
airs 200
emulsion tubes f11

What do you guys think? Before the dyno I was thinking of larger air corrections (up to 210's)....is this the right track?

thanks in advance

nathan
Old 02-01-2006, 02:42 AM
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