Background:
.B18C1
.75k miles

Motor Mods:
.DC Sports 4-2-1 SS 2pc Header (since Fall '99)
.Axle-back Twin-loop Muffler (since Fall '01)
.Ignition Timing set @ 17 to 18 deg BTDC

Symptoms prior to major problems following timing belt procedure:
.black, sooty exhaust after ~5500rpm (all gears)
.dyno'd 146whp / 116lb*ft in Feb '02 with current mods + K&N RU-3130 (put stock filter back on)

The exhaust ports had carbon caked up to up to ~1.5mm in thickness. I scraped out ports #3 and #4 with a standard screwdriver. Sick.
http://portfolio.iu.edu/bchang/Pics/..._Chips_001.jpg
http://portfolio.iu.edu/bchang/Pics/..._Chips_002.jpg
http://portfolio.iu.edu/bchang/Pics/..._Chips_003.jpg

What was still leftover in ports #1 and #2 even after what you see about dropped out onto the floor.
http://portfolio.iu.edu/bchang/Pics/...tovers_001.jpg

Port #1
http://portfolio.iu.edu/bchang/Pics/...Cylinder_1.jpg
Port #2

Port #3

Port #4
http://portfolio.iu.edu/bchang/Pics/...Cylinder_4.jpg

The intake valves (whiter ones) are gritty...probably a sign of consistently high cc temps or detonation.

Using carb cleaner, we sprayed the backs of the intake valves and they leaked into the combustion chamber. Uh oh. I'm wondering if I need all new exhaust valves too. I guess the machine shop can tell me that.


Cylinder #1
http://portfolio.iu.edu/bchang/Pics/...Cylinder_1.jpg
Cylinder #2
http://portfolio.iu.edu/bchang/Pics/...Cylinder_2.jpg
Cylinder #3
http://portfolio.iu.edu/bchang/Pics/...Cylinder_3.jpg
Cylinder #4
http://portfolio.iu.edu/bchang/Pics/...Cylinder_4.jpg

The intake plenum and back of throttle plate were oily (wet), not just sooty (dry). Plugs #1 and #4 were black, while #2 and #3 were still fresh (new plugs 1k miles ago).


The previous episode:
https://honda-tech.com/zerothread?id=220093


[Modified by IN VTEC, 7:39 PM 7/9/2002]

 

Just a note:

Cylinders and spark plugs #1 and #4 are black b/c of the mishap. They should look just like #2 and #3 if something bad had not of happened.