ill work on pics. my roommate detailed the bird the other day... i still need pics of that too before I screw it up again lol

 

That's what I thought too. But who is the original author?
I gotta take some time to soak it in as well. Sorry, but I don't have a lame-o excuse like a hangover!!!

 

hey man lol. its my "weekend" i get tues and wed off, and work sundays. i tend to do a little drinkin on my weekends. ask alih

 

OK, now that I've had time to let it ferment in my brain (or in Spec's case, pickle) let's continue our rebuts...
Kyphur, I don't know if maybe you're mis-reading the intent of our commentaries? We are mainly referring to the engine running rich out the exhaust due to the physical intake/exhaust valve timing cycle of our cams. By "we" at this point I guess I'm saying me, since I can't speak for Spec. I can only speculate what Spec was speaking of!
The basics of the cam operation are:
The intake valve is opened before TDC when the piston is still rising on the exhaust stroke.
On the intake stroke, the intake and exhaust valves are open at the same time.
After TDC, the exhaust valve closes and the intake valve remains open.
On the exhaust stroke, the exhaust valve is opened slightly before BDC.
Since we're talking about valve overlap (the time in degrees that the valves are open at the same time), what happens if the cam holds the exhaust valve open longer? By nature, a good exhaust system has a "scavenging" effect. If the exhaust valve is held open for too long, some of the incoming fuel can actually get "vacuumed" right out the exhaust valve and blown out the exhaust (our aforementioned rich exhaust).
And, what happens when the cam opens the intake valve too soon? Some incoming fuel could actually turn right around and go back into the intake valve, causing a rough idle, loading up of gas, etc.
I hope that clears up any points I was trying to make earlier? Since the scenarios I described above are physical fuel delivery aspects of the cam, no external tuning in the world is going to circumvent (I thought I'd throw a big word in too since Spec used "intrinsic" ) those actions of the cam.

 

^thats what I was saying.

a larger overlap will always necessarily result in additional unburnt fuel in the exhaust mixture. it doesnt even need to be due to scavanging. the valve will still be open during part of the upstroke and fuel can be pushed out. this is better at higher rpm bc the resistance to flow controls this loss while allowing for better breathing at higher rpm.

my cam is a 232/234@ 0.050 and .595/.598 lift 113lsa. it has close to 300 degrees total duration both int/exh. i realize with smaller hot cams you wont notice it much, but w/ my cam you really do. so thats why i qualified it earlier by saying my AFR is a mildly rich 13.1 at WOT and low 14s cruising. this isnt a rich enough AFR to say my crappy milage is due to tuning issues.

but remember, the motor is moving much more air per cycle, and it compensates by adding more fuel. any time you open a component of the motor up to breathe better the computer will add fuel otherwise you get a lean condition.

 

...Unless your engine doesn't have a confuser!

 

true, but even w/ a carb car you you be moving more air and any good carb owner will tune at least by the plugs

unless im missing something, any time you open up the valve train you will create a lean condition due to the added flow, and you must then add more fuel to create a proper mixture thus bringing down your MPG which brings us back to the topic of this discussion.


EDIT: confuser.... well we can see your bias!

 

Don't you mean bios?
And yes, with a carb engine, the more air you cram in and out, the leaner the fuel mix. I was just giving you crap about how "easy" the self-adjusting computer controlled engines are, as compared to an old school engine where it requires more brain power to problem solve!