-One lifter not turning
-Sound stays weather or not you have ignition to cylinder
-No debris in oil filter
-Exhaust leaks not the sound
-It sounds louder under the motor and on top
How loud is this sound? Have you watched it run without the valve cover on? Were the heads rebuild? If so, were there new guides and/or valves installed? I think Id go back on the Machinist and at least ask some questions about what was gone and did he do anything?
everything looked good under the valve cover, while it was running.
the sound is pretty loud. embarassing at any speed besides low rpm or idle.
the heads were rebuilt. there were all new guides, new valves, hardened valve seats, the whole bit.
I had a lifter go bad in my 390 with 40,000 miles on it. I was able to fish it out from under my edelbrock intake without removing the intake. I used a magnet to pullthe old lifter out then a flexible grab tool to reach in and pull it out through the center hole in the Intake. It is time consuming but worth it in the long run cause you don't have to buy another set of intake gaskets. I put a lifter out of another spare engine I have and have not had a problem since. I have since put another 10,000 miles on it and had not a sound out of the engine.
After replacing the lifters did you notice or check that all push rods were now turning.?? They must all turn. Also checking for a bend push rod roll it on the nice flat table top max out 0.20 but I'd replace any that don't truly roll flat. Have you made sure you don't have a broken or weak valve spring? One thing for sure the longer you run it the more damage you'll do. But you haven't said to much about what was done to the inside of that motor. Like did you have the rods rebuilt on both ends bored or just re ringed, new pistons, turn the crank. Maybe one rod bolts came loose? I've seen some fe over the yrs if just torqued to 45lb a few time and the threads have stripped ez on one bolt. It don't take long before it starts pounding. I would pull it down real fast and inspect it b4 I'd run it any more. It just may save you a lot of money in the long ran. And you already know it's with #3 Like said b4, i would bet the cam lobe is damaged too. I cut a slot in a old pair of v-cover so I can view all the rocker-push rod our turning at 1st startup to make all spinning and oiling good. Then put on my reg valve covers. I've never had a wiped cam lobe in 45 yrs form break in. You may get a oil mess by starting it up with out valve cover but that's was old school stuff, plus adjusting the rockers Hot when it was running way back then..my 2 cents
I ran out of time on monday, so tomorrow, right after work I am going to pull it back in and check that all lifters are turning. And I am not driving it at all know. not untill I get this figured out for sure.
I will respond tomorrow.
It really doesn't matter if all the pushrods & lifters are turning if the noise is not the lifter. You know what a tapping lifter sounds like as you did the test pushing on the lifter end of the rocker arm. I think you have determined it is not lifter noise, at least that is the impression I get.
You noted before that the pushrod was not turning. You also noted that the bottom surface of the 'offending' lifter had a different wear pattern than the other lifter. The lifters actually ride on the edge of the cam lobe, the contact point being off center of the lifter surface. That causes them to spin. If the cam lobe is worn, you can see pits in the edge of the lobe.
I think you have two problems. I think your cam was bad from the get-go, not that you did anything wrong. Especially when you went through all the valves with the intake off and checked clearance. As long as you were somewhere in the lifter travel, it should have been ok. The clearance might have closed up by a few thousandths when it got hot, but if you had 'clack' clearance when you pushed on the rocker, you should have been fine. [clack is the noise it makes when you push the rocker arm and let it go when the lifters are dry ... my word]
The noise is likely in the short block. You need to consider what parts were replace and what were re-used when the block was built. If the pistons / rods / wrist pins were re-used that may be the source of your problem. What did you pay to have done? Did you get an itemized list of parts replaced?
Again, I think the cam was gone from the startup. Manufacturer defect or a 'used' cam gotten from some other source. When it is removed, inspect the lobes for 'differences'. You may find the guilty party just looks DIFFERENT, especially on the edge.
Wordy mode over.
thats a good explaination. The "offending" lifter was barley worn "differently". there were no pits or any difference in the feel of it if you were to run your finger across the base. I just looked like it was worn differently.
I really gotta decide what I am going to do here.
I basically got all the parts from a guy who had the machine work done to block, heads redone, wrist pins pressed in to new pistions, new bearings etc. all work was done by machine shop in denver. this shop did everything so the guy I bought it from could just assemble it. well he lost his job, put everything in craigslist for 500 bucks. I went a picked up everything. he had recipts between new parts (pistons, cam lifters etc.) adding up to over 2 grand.
I took everything back to the same machine shop and paid to have the short block built with no warrenty because evrything left the shop