I loosened the rocker arms to make sure the valves stayed closed. I was thinking maybe a stuck lifter was holding them open and not allowing compression. Anyhow, it solved nothing... <img src="/forums/images/graemlins/frown.gif" alt="" /> Compression is like this:
Cyl. 1- 145 dry, 150 w/ oil
Cyl. 2- 30 dry, 35 w/ oil
Cyl. 3- 140 dry, 150 w/ oil
Cyl. 4- 145 dry, 155 w/ oil
Cyl. 5- 135 dry, 145 w/ oil
Cyl. 6- 140 dry, 150 w/ oil
I can pull the plug wire on the #2 Cyl. and it makes no difference in the way the truck runs...crappy as ever. There's just no compression. If there's water in the oil, and I have a new head gasket and head, could it possibly be anything else other than a cracked block? Also what do you mean by a cracked piston, timing, and mixture? I'm grasping for any glimmer of hope!

When you had the heads off, did you carefully inspect the heads of each pistol to insure there were no cracks or holes in the top of any piston?

Even a small hole is a pistol will kill its operation, It will not have vacuum to suck in the gas/air mixture during the intake stroke, it will not hold pressure during the power stroke, and it will not have much compression during the compression and exhaust strokes.

I looked at each piston top, however there was a lot of carbon buildup and I may have missed something. I cleaned them as best I could, which unfortunately wasn't very well. Would a hole in the piston cause a lot of blowby?

Mike did you change the oil? Is there new coolant in the new oil? If yes you must have a really bad block.
If no then you need to pull that one piston.. you should have already done that anyway. You have a very bad piston ot a crack in the block is what I would suspect from here.
Big JIm <img src="/forums/images/graemlins/pfft.gif" alt="" />

Mike mostly the pistons get CRUSHED between the rings and distort causing the blowby on the side and not thru a hole like you are thinking in the top of the piston.
Sometimes the sides of the cylinder are scored with up and down grooves from broken rings, etc.
Big Jim <img src="/forums/images/graemlins/pfft.gif" alt="" />

What do your timing chains look like? I'm in the middle of a rebuild on my 258 (almost done!!!). My original timing chain had over an inch of play in it. <img src="/forums/images/graemlins/scared.gif" alt="" /> If valves are not opening up on time that could cause some damage. But my motor is also 26 years old, and I don't think the previous owner\s took very good care of it. Good luck. Hope ya'll can get your rides up and running.

Well all, I pulled the engine this weekend, and Jim was right...when I yanked the #2 piston, the first thing I noticed was the not-so-nice sound of all the little pieces of shattered rings hitting the floor. The piston was completely chewed up between the ring grooves, and my cylinder walls were pretty scored after all. the deepest scratch mic'd out at 5 thousandths, too much to hone out. And yes, my timing chain was sloppy as hell also. As to the antifreeze question, I think I had a blown head gasket because since I replaced it there's been no more watery oil, so whatever was in there before must have been residual. Sooo...I'm sending the block off to be bored 30 over, just to be safe. Anybody know a place with fast shipping and good parts to order new oversize pistons from? I'd like to get this done this weekend if possible. Also, anything else I could do (with a reasonable amount of money <img src="/forums/images/graemlins/smile.gif" alt="" />) for performance upgrades while I have this thing out? I'd sure like to be able to pass people on the highway again... <img src="/forums/images/graemlins/kewl.gif" alt="" />

Mike I don't think you have posted where you are.. I ALWAYS advise the closest or a nearby machine shop! Returning stuff long distance is a real pain!
If no machine shop is nearby then look to the next town or the largest around.
Big Jim <img src="/forums/images/graemlins/pfft.gif" alt="" />

sounds like the perfect time to do a 4.0 head and tbi fuel injection!

What a fasinating thread!

C. <img src="/forums/images/graemlins/wink.gif" alt="" />