well i just got done doing a compression test after using half a pint of seafoam engine treatment with a half tank of gas. after track day, my compression numbers were all over the place. refer to this post:

https://honda-tech.com/zerothread?id=727981

anyways, after the harsh detonation, my motor put out 170-160-210-180 compression and i was pretty depressed about that. last time i put gas in, i mixed half a tank of gas (~5-6 gallons) with half a pint of the seafoam stuff. i have since filled up a new tank, so i decided to do a compression test. this time it put out 185-175-180-175.

this is on a b16 and i know that these numbers are not even close to stock b16 compression numbers, but i'm pleased with the results just because they're all within the same range. i didn't actually feel a physical performance difference after using seafoam (like some people claim), but these numbers lead me to believe that the stuff actually works

-marc

 

sounds like you had a lot of carbon build up on cyl#3 in order for it to drop the comression that much afterwards.