This may be a very amusing post to read so please bare with me. I have a friend who works with a guy who has a 95 Z28 with some sort of a chip, and an airfoil, and that is it. The motor has 50,000 miles on it and it started to burn antifreeze. So my friend and his co-worker proceeded to do a top end rebuild. I get a call and they are having troubles adjusting valves. So I go out the next night to help. My friend said that he tightened them 360 past zero lash, then rotate the motor 180 and they are loose enough to take the pushrods out. I get there and he is right they are loose, so I have them loosen them all back up and get the motor back on #1 TDC to start over. I am trying to think of what is wrong here thinking there is no way that the lifters bleed off that much.

We finally got them adjusted at just 3/4 past zero lash and called it a night. I just got a call from the guy and he said that the car started fine and he ran it down the road and it runs bad. He said he could probably hold it at 4000 and dump the clutch and it would probably die. He says it smokes now and it didn't before, and he is also seeing a consistent drop in oil pressure almost to the red at idle.

He pulled off the drivers side valve cover and while it is running at idle only one or two rocker arms are seeing oil, and the others are hardly any if any. Then to add to all this he said it has bad blow-by, like it will shoot to the ceiling in the garage.

What could be going wrong here? Could some pushrods of gotten bent? Would that cause all of this? The heads and intake were all bead blasted, could that of gotten down in the pushrods blocking them off, or even ruined a bearing or two in the 10- 15 minutes that he ran it? I am at sort of a loss. I am new to all this as I have only built one LT1, so he is coming to me for guidance and I don't know what to tell him. That is why I am on here asking people that know alot more than I do. I am sorry for the long post, but I had to try and explain the full problem. I searched all over and could not find anything this unique. The didn't touch anything below the heads, didn't even take the lifters or keepers out. I am going out there tomorrow night to listen and look and maybe find out what's wrong. Any help will be greatly appreciated. Thanks, Matt.

 

How long did it run with a coolant leak? Did anyone bother to rotate the crank so they could view all the cylinder walls while they had the heads off??????? Sounds like at least one is scored. Perform a leak down test on all 8. You could also view the cylinder walls now without taking the heads off with a bore scope.

Have him drop the pan and pull off one of the main caps to view the bearing and the crank.

 

He said after about a week back and forth to work he could smell antifreeze burning out of the exhaust, so pulled it down. He said that it still ran great when he tore the heads off, and found the blown head gasket. Then he puts it together and it runs like crap. He said oil pressure is decent until it starts warming up, then it just starts dropping. I am wondering if some sand got down in there and wiped out a bearing or two while he ran it for 10- 15 mins without changing the old oil. I will see if we can get a main off tonight, or maybe add some thicker oil and see if pressure increases worth anything to try and narrow this all down. Does this sound like a good idea? Thanks for the input so far.