4.0L HO Jeep Engine Build
The '92 block took the damage pretty well considering the pounding it took for thousands and thousands of miles. After mic'ng it out, I figured it would take a .040 bore to clean up. I contacted a couple local dealers and they wanted $250+ per piston, so that was out of the question. I did some research and found that Speed-Pro offers a coated replacement piston set including pins for a very reasonable price (about $150) but they were on back order for the .040" oversize.
At this point I figured I'd see if I could find a good shortblock on Craigslist that just needed a hone to save money. I decided on a '99 or later block for a few reasons:
1. They have a stud girdle to reduce NVH and are considered a stronger block.
2. They use pistons with a the thinner metric ring pack which should reduce friction.
3. If I'm lucky, the seller will give the intake manifold with the block (I'll get into this later, but the later intake is a much better piece).
4. Newer block, less mileage (I hoped).
Well, the later block I picked up for $200 had problems too. The rings were again seized on the pistons!?! Dam it! On the good side, the guy gave me two 99+ intake manifolds, two sets of injectors, one good alternator, two sets of exhaust manifolds, a late coil pack and the head and crank were in excellent condition so all in all I did OK. :)
On this late block, one of the timing cover bolts had worked it out and covered the block with a nasty, thick layer of mixed oil, gravel and road grime. It was so bad that I didn't even want to risk mocking it up so off to my machinist it went for a baking, cleaning and boring. The bore on this block only needed a commonly availible .030 over piston set and as mentioned before, uses the thinner metric ring pack. The first picture shows all the road grime and the second shows the girdle that comes standard on the later block.
The '92 block took the damage pretty well considering the pounding it took for thousands and thousands of miles. After mic'ng it out, I figured it would take a .040 bore to clean up. I contacted a couple local dealers and they wanted $250+ per piston, so that was out of the question. I did some research and found that Speed-Pro offers a coated replacement piston set including pins for a very reasonable price (about $150) but they were on back order for the .040" oversize.
At this point I figured I'd see if I could find a good shortblock on Craigslist that just needed a hone to save money. I decided on a '99 or later block for a few reasons:
1. They have a stud girdle to reduce NVH and are considered a stronger block.
2. They use pistons with a the thinner metric ring pack which should reduce friction.
3. If I'm lucky, the seller will give the intake manifold with the block (I'll get into this later, but the later intake is a much better piece).
4. Newer block, less mileage (I hoped).
Well, the later block I picked up for $200 had problems too. The rings were again seized on the pistons!?! Dam it! On the good side, the guy gave me two 99+ intake manifolds, two sets of injectors, one good alternator, two sets of exhaust manifolds, a late coil pack and the head and crank were in excellent condition so all in all I did OK. :)
On this late block, one of the timing cover bolts had worked it out and covered the block with a nasty, thick layer of mixed oil, gravel and road grime. It was so bad that I didn't even want to risk mocking it up so off to my machinist it went for a baking, cleaning and boring. The bore on this block only needed a commonly availible .030 over piston set and as mentioned before, uses the thinner metric ring pack. The first picture shows all the road grime and the second shows the girdle that comes standard on the later block.
