Rust on the engine block mating surfaces and such

[CodeWarrior]

Rust on the engine block mating surfaces and cylinder walls

I have a defunct 2004 Liberty. I purchased it originally intending to cannibalize it for parts, but then took pity on it and decided to try and revive it.

Here are some images taken when I first got it back in July:
Imgur Album - "New" Jeep Liberty

I have removed the engine (3.7L) from the cargo compartment where it apparently has resided for several years, and have taken it down to my workshop and mounted it on a new engine stand which I purchased just for this project.

I took the cylinder heads to be surfaced as there was a slight warp due to an overheat apparently caused by radiator leak (it remains to be seen if this is the only problem). Having sat for so long partially disassembled (it came to me with cylinder heads removed, and timing chain cover removed), there is now rust on the mating surfaces of the block for the timing chain cover and cylinder heads.

This is my first rebuild. Consider me a novice. Is the engine block still serviceable? I see that in the factory manual, a white, 120 grit 3M Roloc bristle disc can be used to clean the surfaces on the cast iron block. Does the presence of rust (even cleaned off) make the engine block unusable as it introduces potential seal problems? Three of the cylinders have rust present on the cylinder wall. See the album below for a look at the rust.

Imgur Album - Engine on Stand

I plan to fully rebuild the engine as I don't know what all has been done to it. I expect to replace the pistons, bearings (crankshaft and connecting rod), timing chain components (some of the guides are missing anyway.

Please let me know what you think.

 

[tommudd]

Slight surface rust is fine as long as there isn't any pitting on the mating surfaces
Just sand off and go

 

[ltd02]

x2. Pitting is a bad thing. I'd probably just try a mild scrubbing pad on that. Maybe soak it in a bit of oil. When I did my HGs, I had things apart for about a week as the heads were gone over. I coated everything (gasket mating surface and exposed cylinder walls) with oil and cleaned it off with some brake clean and alcohol before setting my new HGs.

 

[M38 Bob]

A proper rebuild will require cylinders to be honed at the very least, probably require boring for oversize pistons. Crank turned or polished for new bearings, and entire assembly vatted. To just freshen up the rings and bearings plus a valve job, if you're lucky enough to get any decent service out of it, the minor surface rust is a minor factor.

Bob