Carbon Buildup on Valves

[Supersuk]

I recently purchased a complete engine/transmission, suspension, axles, wiring, etc from a salvaged 2018 CTR to swap into my 2018 LX sedan with a manual trans and 2.0L NA engine. I have no history on the engine other than it has 98k miles on it. I did the usual compression and leak down test to see the health of the motor. All cylinders checked out at 200psi compression cold with less than 1% leak, except for cylinder #4 with almost no compression and about 75% leak at intake valves. Took apart the intake manifold and found gobs of carbon buildup in the port and on the valve itself. I was taking out chunks bigger than 1/4" in thickness. I'm sorry, but I didn't take much pictures of the actual buildup, but trust me there was a lot. The first pic of dirty valves was while I was cleaning it and remembered to take a pic. I used a liquimoly valve cleaner, metal picks, a drill with zipties strapped together to agitate the carbon, and finally a walnut blaster. The second was after cleaning, but what doesn't show well is that behind the valve stem, there was still a lot of carbon that I couldn't see. It could only be removed after disassembling the head and removing the valves. I had to do this because the leak down numbers didn't change much after the cleaning. After removal of the head, it turns out that there was a lot of carbon buildup on the seat and valve mating surface. A quick lap restored the sealing surface and everything measured out good. After assembling the engine, I get perfect compression and leak down numbers. One word of caution is that if your leak down results show that you have some leakage through intake valves, i'd prolly recommend that you take off the head to clean the intake valves because the liquid that I used to soak and loosen the carbon will leak into the combustion chamber.

The quick take away from this post is that all CTR owners will someday have to clean their valves and intake port. Unfortunately for us, the intake is on the rear of the head with very little access for equipment to clean it. It is easiest with the head off.

 

[bigbacon]

this is what direct injection does. No more fuel on the valves to help clean them from all the junk being sent back in by the PCV system.

 

[speedyserg]

A little direct port injection setup should help lol

Port the head, upgrade the valves and valvetrain - easy 50whp gain and fresh head

 

[Mufasa]

When you finish this can you tag the vivid dreams civic swap guy? They’d go nuts

 

[Fountainhead]

I recently purchased a complete engine/transmission, suspension, axles, wiring, etc from a salvaged 2018 CTR to swap into my 2018 LX sedan with a manual trans and 2.0L NA engine. I have no history on the engine other than it has 98k miles on it. I did the usual compression and leak down test to see the health of the motor. All cylinders checked out at 200psi compression cold with less than 1% leak, except for cylinder #4 with almost no compression and about 75% leak at intake valves. Took apart the intake manifold and found gobs of carbon buildup in the port and on the valve itself. I was taking out chunks bigger than 1/4" in thickness. I'm sorry, but I didn't take much pictures of the actual buildup, but trust me there was a lot. The first pic of dirty valves was while I was cleaning it and remembered to take a pic. I used a liquimoly valve cleaner, metal picks, a drill with zipties strapped together to agitate the carbon, and finally a walnut blaster. The second was after cleaning, but what doesn't show well is that behind the valve stem, there was still a lot of carbon that I couldn't see. It could only be removed after disassembling the head and removing the valves. I had to do this because the leak down numbers didn't change much after the cleaning. After removal of the head, it turns out that there was a lot of carbon buildup on the seat and valve mating surface. A quick lap restored the sealing surface and everything measured out good. After assembling the engine, I get perfect compression and leak down numbers. One word of caution is that if your leak down results show that you have some leakage through intake valves, i'd prolly recommend that you take off the head to clean the intake valves because the liquid that I used to soak and loosen the carbon will leak into the combustion chamber.

The quick take away from this post is that all CTR owners will someday have to clean their valves and intake port. Unfortunately for us, the intake is on the rear of the head with very little access for equipment to clean it. It is easiest with the head off.

Wow, great job!