engine swap?

[napew2009]

thanks in advance. My question: Does a motor with 150+ compression on all pistons make for a good motor? I have a 99 expy eb with 5.4 ltr engine. It's high mileage 330K km (approx 180K miles) truck. i've had it for two years. First of all it leaks oil and second it's noisy (tappets?), and third it's blown out blue smoke at a few cold starts. anyways I wanna just start over fresh with an engine swap. the engine swap ive found has roughly 140 km or 80-90 miles on it. Would this be a wise choice to buy this motor?

 

[ecqm8000]

In general compression should be even in all cyls. Wet/dry (how long since it last ran) piston rings will have an impact on PSI. That engine sounds like it is a good engine.

On the other side of the coin. An engine with eight spun rod bearings and broken exhaust rockers MAY be able to give those results.

Is the current engine in a vehicle that is still running? Will the seller guarantee the engine?

 

[napew2009]

thanks for the reply. Well the engine's at a local auto wreckers and they do have warranty for their engines. I bought one there b4 and was very happy with it. /the engine on mine still runs but you can tell she's starting to show her miles. So the compression should b all the same on all cylinders?

 

[ecqm8000]

There will always be some variance between cylinders, it may be hard to measure but there will be some. Compression checks are to find burned or bent valves, bad gaskets or rings and even if the valve timing is in the right place. In the old days (as today) two cyls next to each other that had low comp and the others were higher, indicated the head gasket between those cylinders had given out. We would do a check dry and record the numbers, then we'd squirt some oil in the spark plug hole and test again. If the numbers rose significantly, it indicated the rings we just about finished. That was on an engine with low numbers to begin with. The engine you speak of has good numbers to start with.

Engines today, if maintained will last a long time (Certain rotaries and early Hyundai engines excluded). Does that wrecking yard require a core? Consider building your old engine, or selling it to some one whose miles are adding up and would like to do theirs. It is always nice to find a "running" core to do a build, rather than one that is a core for a reason.