Hi-port intake swap (medium)

[Robert Legere]

*****First off, the intake manifold flows more than enough air for even a
fairly well modified engine, and is difficult to port. So save your time
there! And secondly, the head really responds well to porting if you do it
correctlyl. I've seen 23% more airflow on my flowbench with stock valves
and moderate porting. I'd clean up the intake ports a little, and work a
little harder on the exhaust ports. Get a good header, larger exhaust
(check the archives, right Geo?), and think about some cams and an ECU.
You'll have a torquey SOB engine than revs clean and will lay waste to many
cars with a higher pedigrees.
	Regarding the polishing of the ports. I polish the exhaust ports very
smooth, down to 320 grit. Less carbon buildup. Intake ports I leave at 80
grit. It's not as critical for an injected engine as a carb'd engine. A
carb'd engine is essentially a "wet" manifold, it sees air and fuel, and
the fuel can settle out of the airstream and cling to runner walls. Rougher
is better in this case. But the SR20 has what is essentially a "dry"
manifold, the injectors are right above the valves, and the runners can be
fairly smooth since the fuel is injected under high pressure and is well
atomized.

Bob

-----Original Message-----
From:	Peter Serwe [SMTP:peter@easytree.net]
Sent:	Thursday, April 04, 2002 5:53 PM
To:	se-r@lists.deskmedia.com
Subject:	Hi-port intake swap (medium)

Guys,

Okay, first off, I'm too cheap to buy a turbo kit for now, I can't
forsee it in the next year, maybe in 2-3.  For the time being, I have a
non-egr intake manifold, and I'm gonna port it, I also have a extra head
that I'm going to port/polish the exhaust as well. <snip>