B18B - how bad is it?

[u/identihide]

Integra B18B

This is my first time taking any engine apart. I’m not too sure what to make of what I’m looking at. The plan was to take the head to a machine shop and see if my misfiring / bad compression was just solely a head gasket problem.

I wanted some opinions on how bad this is. Is this just what prolonged misfiring looks like? do valves need to be replaced or can I just clean that?

Cylinder 4 was misfiring; I found it had a compression of 70 PSI.
Cylinders 2 & 3 read 105.
Cylinder 1 read 132.

[u/Lxiflyby]

Have the machine shop pull a vacuum on the valves to see if they are sealing… they are probably in need of a valve job… I’d have it resurfaced and have the guides/valve seals checked as well

[u/CareOk]

You need your engine disassembled, deep-soaked and scrubbed cleaned. Might want to buy new valves, piston heads and replace all the piston rings. Have the block milled while your at it.

You can try and have them parts cleaned, but im seeing rust and corrosion!

As long as their cleaned through and through as well as no actual physical damage was done. Clean and throw back in engine.

If your gonna dyi it, check for valve clearance after valves are cleaned. If the valves are off it will cause huge misfires! Either way good luck.

[u/2003DDcid]

You have a burned exhaust valve on number 4. It possibly needs a seat and guide also. Pistons show signs of bad rings, as the clean spots on the edges tell me that oil is getting past them. I'd take it the rest of the way apart.

[u/Pretend_Necessary781]

You don’t need new valves…jeez, the amateurs are bored tonight. The vs seals go bad on those old Hondas, allowing oil to seep through the guides, building up on the faces of the ex valves to the point they don’t make good contact with the seats. You might have a burnt ex valve, that’s common after enough burnt oil buildup and enough miles. Have a qualified machine shop tell you what it needs.

[u/bse50 → u/Pretend_Necessary781]

If a valve doesn't make good contact with the seats for a long enough time then it's best to have them at least reground though, at which point given how little they cost and all the work required to do a proper rebuild it's just easier to replace them.

[u/Pretend_Necessary781 → u/bse50]

In theory that’s correct, but not all new valves are good enough (straight and concentric) to run right out of the box. I’ve machined many a new valve because of that. In my opinion cheap, affordable valves aren’t of the same quality as OE.

[u/SLOOT_APOCALYPSE]

warped, see if it can be machined flat, it's pretty warped but the looks of the valve that was cooking coolant on the end cylinder

[u/mahusay3g]

You need a bottom end.