You want to lower your cylinder pressure-directly relates to temp. Increasing valve overlap is one way to reduce the cylinder pressure. Advancing the intake cam and retarding the exhaust cam will achieve this. Just be careful, because doing that will reduce your piston to valve clearance. And as far as the catalytic converter goes, just because the HC/CO (oxidation)portion of the cat is working, that does not mean that the NOX (reduction) portion is o.k. Your NOX is high, even for a car without a cat, so once you get the engine operating properly, if your NOX is still above the cut points, then look at the cat.
Oh, and remember to reset the ignition timing any time you change intake cam timing.

 

<TABLE WIDTH="90%" CELLSPACING=0 CELLPADDING=0 ALIGN=CENTER><TR><TD>Quote, originally posted by b19coupe &raquo;</TD></TR><TR><TD CLASS="quote"> Increasing valve overlap is one way to reduce the cylinder pressure. Advancing the intake cam and retarding the exhaust cam will achieve this.
</TD></TR></TABLE>
Wouldn't the intake cam need to be retarded and the exaust advanced to increase valve overlap?

 

No. For some reason, this particular technical issue is widely misunderstood.
Four strokes in order are : intake-compression-power exhaust. Overlap occurs when the exhaust valve(s) is closing at the end of the exhaust stroke and the intake valve(s) is opening at the beginning of the intake stroke. If you retard the exhaust cam, the exhaust valve closes later, the later it closes, the more overlap you have. When you advance the intake cam, the intake valve opens sooner, the exhaust valve has not yet closed. That is why, when you run really big cams, you can't go too much advanced on the intake and retarded on the exhaust, the valves will actually hit each other.
I had to check this on my head because I am running really big cams. I took an old timing belt and wrapped it around the timing gears and used vise grips to hold it so I could rotate the cams and watch to see if the valves hit each other. It was scary to think of the valves hitting each other at high rpm, they come really close.

 

<TABLE WIDTH="90%" CELLSPACING=0 CELLPADDING=0 ALIGN=CENTER><TR><TD>Quote, originally posted by b19coupe &raquo;</TD></TR><TR><TD CLASS="quote">Increasing valve overlap is one way to reduce the cylinder pressure.</TD></TR></TABLE>
This was my initial thought until I was steered in the wrong direction. It all made sense until I got my test results. Increased overlap here I come!

<TABLE WIDTH="90%" CELLSPACING=0 CELLPADDING=0 ALIGN=CENTER><TR><TD>Quote &raquo;</TD></TR><TR><TD CLASS="quote">And as far as the catalytic converter goes, just because the HC/CO (oxidation)portion of the cat is working, that does not mean that the NOX (reduction) portion is o.k.</TD></TR></TABLE>
I hear ya, but the CAT is off of a 90 Laser, so I'm not even sure if it has a NOx reduction chamber.

 

<TABLE WIDTH="90%" CELLSPACING=0 CELLPADDING=0 ALIGN=CENTER><TR><TD>Quote, originally posted by b19coupe &raquo;</TD></TR><TR><TD CLASS="quote">No. For some reason, this particular technical issue is widely misunderstood.
Four strokes in order are : intake-compression-power exhaust. Overlap occurs when the exhaust valve(s) is closing at the end of the exhaust stroke and the intake valve(s) is opening at the beginning of the intake stroke. </TD></TR></TABLE>
Ok, I was thinking backwards. Good description, thanks.

 

Okay, "Plan B" worked well, but I still failed by 100 on NOx. I put in a lower-temp thermostat, (170°), & now, just to be sure, I want to rig my radiator fan so that it will stay on. However, I have a question; will the ECU use the fuel map for warming the car up, being that the coolant will be cooler than it should be? Either way, I'm still not very good with electrical ****, so if someone could also tell me what I need to do to get my fan to always run, I would greatly appreciate it.