I have a stock B18C1 engine in my civic w/ around 100k miles on it. I had the head gasket go a couple of weeks ago. Before I replaced the head gasket, I did a leakdown test and found that cylinder 1 and 2 were both leaking into the coolant. After replacing the head gasket, I lashed the valves and set the ignition timing. I found that the engine still seemed to idle somewhat rough sometimes, and also found that it had a kind of miss at higher rpms (~4000rpm+).

I did a leakdown test last night and found that leakage in cylinders 2-4 was around 13% @ 90PSI, and they all leaked into the crankcase. This was not unexpected for an engine with over 100k on it it. However, I found that cylinder 1 was leaking at around 40% @ 90 PSI, and I could hear it leaking into the exhaust.

I can't say for sure whether or not the valve was leaking before the head gasket replacement. The car was showing signs of head gasket failure. I did the leakdown test, which confirmed those signs. So I didn't suspect that there was another leak. I can say that when I had the head off, I had filled the combustion chamber with seaform and it was not leaking out. However, I wonder if seafoam might be too viscous to detect a leak.

What I'm wondering is, is it safe to drive the car as-is? This is my only car currently, so I don't have the time to have the car down for several days. However, I don't want to risk permanent damage to the head and/or block. Thanks for the replies.