yes, another carb size thread

[Dave Severson]

So, the readings we get off the sensor in the collector while on the chassis dyno, or looking at the A/F gauge at the end of a run isn't reading it correctly????? Why not????

[Dave Severson]

I don't much care about average.... Kitz suggestion on the permanently installed O2 sensor and gauge is quite economical..... very similar to what we run in the drag car..... I don't get why it is not an accurate A/F ratio?????? Seems to be an excellent tuning aide, no more plug problems since we started using them.

[Dave Severson]

Guess I didn't know we were talking computer controlled carbs..... Do people really try to use that junk on a hot rod or a drag car?????

We welded a bung in each collector for the o2 sensor trying to balance one side against the other...... Next thing we're going to try is the old 4 into 2 into 1 merge collectors.... Then see what happens to the A/F ratio when trying to employ a bit better scavenging.... We've got very good baselines on both cars, so it should be easy to match performance gains or losses, and at the same time keep a close eye on what the collector changes due for the cylinder scavenging.... Now if we could just figure out a way to measure the effects of scavenging...... Maybe a change in the velocity of the exhaust, or is that more or less controlled by the engine???? Probably not a big deal, just the usual pre-season "how can we make it better?" stuff.....

[Dave Severson]

Yeah, we have the bungs in each collector already, think I'll just put another gauge in the car and see.... Now if I could just find a driver to look at them!!!!!!!!!! If it wasn't for a rev limiter, they'd probably never bother looking at the tach!!!!!!!!!!!! Maybe I could figure out a way to put a recorder of some kind on the O2 readings, or win the lottery and buy a data acquistion system!!!!!!!!! ......or just give it all up and go fishin'!!!!!!!

Think I have a baaaaaaad case of the pre-season jitters.....

[kitz]

Using just the O2 sensor you can get the carb running pretty dang good. You will see changes to every part including jets, squirter sizes, pump cams, and pump sizes. Trying to do all this by reading plugs is inefficient and just plain dangerous IMO. If you want to spend ~$400 you can get an O2 kit that lets you record the data and download and process on your CPU. Otherwise, for most street uses, the gage will work fantastic.

Denny you lost me with all that.

Kitz

[kitz]

OK. Thanks for the clarification. I do in fact have an O2 bung in each collector.

Kitz