Hello,
Since I'm still up in the air on my choice of heads (The verdict is still out on my mystery heads...casting number 14102187) if in fact I do decide to use them they have no exhaust gas crossover. First question: Does ANYBODY make a TBI manifold with an external EGR setup? Second Question: Can I modify my stock intake to accept an external EGR setup? Third question: How come when I search old posts on this subject I see guys from California posting that they pass emissions with NO EGR?

I posted a while back about the effectiveness of EGR, and got some good answers. But now that I searched the archives I see posts from all sorts of people who pass emissions with no EGR valve. How is this possible? If it is-why the hell do we have EGR valves? I realize that another function is to curb detonation by lowering cylinder temps, but is there another way (aluminum heads, premium gasoline, coolant additives etc...)?

Ok, last part. Can the stock manifold be modified? I've looked at it and I can't seem to find a good place to drill a hole and tap a fitting to feed the EGR valve. It seems like the distance between the head and the valve itself is too small to fit anything, but can I tap in at some other point? Or how about this idea...run stainless steel line from the exhaust manifold to the intake manifold (fabricate a flange to match the EGR flange) and mount the valve itself inline somewhere?

Any ideas are appreciated,

Matthew C. Hall

 

Seeing as how I am probably one of the ones you saw that passes emissions without the EGR (mind you sniffer not visual... no EGR means I cant pass visual) I cant say it has any great effect. I dont have detonation problems, and fuel mileage is what I expected it to be. Would it run cleaner, be less prone to detonation, and get better mileage (like Glenn) if I had one? I cant say since I dont have one on there, but I cant see how the emissions could get any lower or how I could end up with less detonation, seeing as how I have none and I tried to get it to detonate. There are ways to help prevent detonation, but that requires taking the heads off. This may have something to do with emissions too from what I have seen and read.

As for your EGR, I cant help much but Ill throw my .02 your way.
What you need to make it work is exhaust from the manifold or headers, a tube running to an EGR mount (take a look at the Fieros and other GM 4 and 6 cylinders with EGR valves hanging out in the breeze) and then pipe the exhaust from there into a hole drilled into the intake somewhere below the TBI. You might even be able to hook it up to a vacuum port on the manifold, but I think under the TBI would provide better distribution. Dont let anyone convince you to run an EGR plate under the TBI like some of the older carbed cars used, they dont last and quite a few of them burned up.

 

Thanks Max...I'll have to check out some other GM EGR setups. If I don't settle on some 50 state legal heads I'll go for the L98 aluminums w/a homebrewed EGR setup.

Later,

Matt