Compression/Leak-down: Should I Bother?

[Smoove1010]

Greetings! I'm about to join the first-time-engine-drop club, and need a little feedback: The patient: 87 3.2 Cab, 99K miles, dubious maintenance history. The symptoms: starts and runs well but feels tired. Burns a quart of oil every 300+/- miles. Starts up with a blue puff, sometimes a blue cloud. The plan: drop engine, send heads out for new guides and to fix whatever else is broken or worn. Have P’s and C’s checked and measured for wear at the same time. Engine is bone dry, and oil pressure looks good, so I don’t want to split the case, but I’ll check wear points, take a rod or two off and see how the bearings look and let the results determine how far down the slope I slide. The Question: If I’m already committed to the drop-and-pop, is there anything to be gained by performing a compression test and/or leak-down first? Thanks in advance for any thoughts… GK

[Bob Kontak]

Bearings and P&C's are pretty stout.

If you are committed to pulling them (P&C) off and checking stuff, then I say no. If you want to run a leak down test to check if the rings are in decent shape with the intent of not pulling the P&C's, it's worth it.

[Reiver]

maybe, maybe not. A leak down will tell you about the 'shape' of your rings/pistons/valves. If you only wanted to do the heads then a leak down would be a good idea to confirm everything else was good.
If you are doing a total top end there would be no point to it.

[James Brown]

would be easy to pull the cylinders while you have the cylinder heads off and check everything out, bet a good piston cleaning will help. When i get a low cylinder, off it comes and everything gets cleaned, sure helps.

[kidrock]

with around 100K, I doubt that you'll need anything other than refurbishing the heads, burnish the cylinders and I'd go with a ring set. Have the heads done by a reputable guy with P-car experience. Cutting corners doesn't seem to work very well with these cars.

[shrtshck]

Your engine is at the same point at which I did the top end of mine. Could be interesting to have before compression numbers but as it sounds you are already committed to doing the work I'd just move on to the drop.
Don't know if the compression numbers you get now will be of much value in providing insight on the condition of the rings. If your motor is like mine was, there is so much oil coming down the intake valve guides that the compression numbers should be considered as "wet" numbers.
As noted by others, do the guides, replace the exhaust valves, replace the dilivar studs, new rings, new chain guides, RSR seals, and button it up.
And enjoy the new found thrust.