Memphetic
15+ Year Contributor
- 115
- 3
- Nov 6, 2005
-
Punxsutawney,
Pennsylvania
I just finished putting together an engine for a first gen... The head is not known good, thought it passed a hydro test while on the bench with the cams out of it.
Cylinder 1 has only 30 psi of compression. This was weird to me, as it passed the hydro test and the rings are new (I expected lower compression, as the rings have not seated, but 30 psi is wrong).
I then went to leakdown test it. I could feel significant amounts of air rushing out of the exhaust, as the downpipe is disconnected. I popped the rockers off and the air discontinued and the only air I detected was that which was coming from the oil pan (which is to be expected).
Obviously the valves are not closing completely at TDC. This also makes sense from before I pulled the engine apart, as there was something that sounded like lifter tick, except louder (loud enough that it caused knock count).
What do you suppose my problem could be here? Thanks in advance.
Cylinder 1 has only 30 psi of compression. This was weird to me, as it passed the hydro test and the rings are new (I expected lower compression, as the rings have not seated, but 30 psi is wrong).
I then went to leakdown test it. I could feel significant amounts of air rushing out of the exhaust, as the downpipe is disconnected. I popped the rockers off and the air discontinued and the only air I detected was that which was coming from the oil pan (which is to be expected).
Obviously the valves are not closing completely at TDC. This also makes sense from before I pulled the engine apart, as there was something that sounded like lifter tick, except louder (loud enough that it caused knock count).
What do you suppose my problem could be here? Thanks in advance.