On top is my EGR plate. That drill bit barely fit into the port, but the end with the tape wrapped around it fit into the hole in the plate, so I made a diagram of how the two meet. The parts with the worst carbon seemed to be where the exhaust needed to make ≤ 180° turns and at the ends, where narrow channels opened and the exhaust went into narrow tunnels.
I was curious how the EGR plate evolved over the years, but I mostly only found EGR block-off plates.
No!
I forgot about reading here
http://ecomodder.com/forum/showthrea...rts-21032.html that you need to drill into the intake manifold and tap bolts.
Honda, thanks for changing that!
I figure that those spots do not collect carbon because they are larger, they are bigger to compensate for the build-up, which I am guessing is a result of the ninety-degree turn.
The thing is, I keep thinking about the big holes and the small ports. If they are half as wide, three-quarters of the exhaust would bounce off the edges and swirl around before getting through, depositing carbon in the process.
Would beveling the ports allow gas to flow with fewer restrictions, resulting in less build-up?
If this took 195,000 miles to clog, would cleaning it 100k maintain MPG?