What is wrong with my engine? UPDATED MARCH 2

[Headrope]

I've got a '68 383 in my '66 Charger. It's bored .40 over and has a Street Hemi grind Purple Shaft cam. Stock heads with hardened seats and springs/tappets to match the cam.
Intake is a 625 CFM Carter Competition Series 4bbl sitting on top of an Edelbrock Performer 383 manifold.

Symptoms: Engine was freshened up(by me) with new main/rod bearings and a fresh crank, and dialed in by pros I trust that have been working on Mopars for more than 40 years. Car ran excellent for the first day, but then started smoking out the right (passenger side) exhaust pipe. I have dual pipes with no crossover. During the freshening up I pulled the pistons and I didn't change the rings (they had less than 50 miles on them before being pulled).

Pulled the plugs and they all look a little rich but okay. Numbers 3 and 5 had some gas on them; number 8 had oil.

Compression numbers are all in the 125-130 lbs range except number 8 which barely even registers at 5 lbs.

I'm frustrated, angry and probably overlooking the obvious, so am looking for second, third - as many other opinions as possible. What is wrong with my engine?

[resq302]

Sounds like you lined up the rings on the #8 piston or the rings are totally bad.  Personally, I would have put new rings in as cheap insurance when you did the rebuild.  Did you have the cylinders bored?  If not, the cylinder could be out of round (egg shaped) which is causing the oil to foul out the plug.

[8WHEELER]

I would have put new rings in. Did you ridge ream and hone the cylinders? it is easy to break rings if you still have a ridge there.
I have seen people break rings with a fresh bore as well. Did you put the rings down in the cylinder first and gap them?
Yes you can get an oil problem if the ring gaps are in line with each other as well. No matter what its coming out 

Dan

[Headrope]

My gut told me to change the rings for the heck of it, but a buddy whose only been wrong once ever - now - talked me out of it.
Guess I need to pull it and crack it open again.
Thanks for the input.

['CUDA360]

What about a valve problem.  Did you do  a leakdown check yet?  All that oil in there could be a bad valve seal or worse....

[8WHEELER]

But the low comp in that cylinder would indicate a ring problem, if it had a bad valve and that was the reason for
the low comp, it would not be blowing any smoke.

Dan

[Headrope]

The smoke is not on initial start up. It's almost as if it takes a minute or two for it to build and then the right side tailpipe smokes like a big fatty rolled by Cheech and Chong.

I've done a little more investigating. Here's what I've found. What do you think:

I pulled the valve cover and noticed that the right side rocker arm over the #8 cylinder barely moves while the engine is cranked over (not sure if it's intake or exhaust). If I put my thumb on it, it makes a squish noise and will raise- it's as if the extra force of my thumb on the rockerarm (therfore the pushrod) compresses the lifter so that it can push up. I've got hydraulic lifters; perhaps one has blown out?

I also noticed how much oil my oil pump pushes through the rocker arm - it flows big time, filling the rocker arm like a cup. Because the rocker arm is over the #8 cylinder it would seem to make sense that the valve under the rocker arm I'm putting my thumb on is not closing. The rocker arm is not rocking, so oil continues to fill the "cup" until it spills over the sides (this could also explain why it takes a minute or two before the smoke starts; the cup is filling). When it spills, it runs down past the open valve into the cylinder.

Again, I'm only guessing. But it seems to makes sense and I'd like to exhaust every option I can before pulling the engine. Thoughts?

['CUDA360]

Yup.. This is what I'm saying.

I think it's time to pull the head and don't run the motor anymore. That valve might be ready to drop.
The valve could be cracked or all galled up in the guide. All that oil is overpowering the seal and you have oil going in and compression going out.

Best to inspect that head as well as the lifter/pushrod

[Headrope]

How could the valve be galled inside the guide if it moves up and down as long as I apply pressure on the rocker arm? Wouldnt it seem to be more of a lifter issue?

I have no problem pulling the head, but have no reason to suspect something catastrophic because the valvetrain looked fine before I bolted the heads back on after freshening up the engine. And I've got a '66. Just to change plugs I have to crawl under the car. I think to pull the head I'd have to pull the engine, so I want to do what I can beforehand.

How about this: I pull the spring and manually "move" the valve. If the valve moves up/down and I can rotate it around then it would seem to indicate a bad spring. If I replace the spring (i'll replace the seal since I'm already there) and the rocker arm still doesn't fully move it would indicate a bad lifter. Is this so?

[is_it_EVER_done?]

All that sounds fine, but your still not addressing the 5lbs. of compression in that cylinder! It sounds to me like you might have revved it up enough to bend the valve.

If you can do a leakdown test, do so, but I'm guessing you will have to pull the head (no need to pull the engine), and replace the valve.

Is the pushrod bent?

[Headrope]

Went through an illness in the family, an entire weekend without power (and below zero overnight temperatures outside) a pipe inside the house bursting in more ... but have finally been able to dig a bit more into my motor.

The pushrod is not bent. The lifter was stuck in its bore. And after prying it out I made an incredible discovery: enough of the lifter had been ground away that its core was exposed.

The cam looks to be fine - and I figure any major damage has already been done - so I'm going to pop in a new lifter, change the oil and filter and give 'er a go.

Has anyone ever heard of a lifter wearing down before?

[firefighter3931]

The worn lifter could have been caused by any number of issues. I wouldn't run that engine anymore w/o dissassembly, cleaning and inspection. All that lifter material is throughout your engine and some of it is in your bearings, oilpump and oil passages. The engine needs to be flushed at a minumum. Drain the oil and look for shiny particles in the contents....there will be some.

As for the cause, improper lubrication, improper machining, no lifter rotation, excessive spring pressure, poor quality materials....take your pick 

Ron

[Just 6T9 CHGR]

Isnt the cam softer than the lifter?   I would suspect a worn lobe as well.
I also agree with firefighter......a lot of metal is in that engine now.. 

[firefighter3931]

Isnt the cam softer than the lifter? 

Correct. The problem with todays low quality lifters is that they're not as "hard" as they used to be. Basicly, you want the lifters a lot harder than the camshaft so that they don't eat each other. The closer the lifter and cam lobe are together in terms of "hardness"...the greater the chance of failure. 

Other issues amy come into play, specificly machining. If there isn't a crown on the lifter it won't rotate in the bore. No rotation will kill the lifter and wipe the lobe. Other factors such as oil additives and excessive spring pressures also come into play, but likely weren't an issue in this failure.

Ron

[Headrope]

The springs were matched with the lifters and cam, and all worked fine together prior to my freshening up the crankshaft, and main and connecting rod bearings. No machining was necessary; clearances were within specs.
It's weird - and frustrating as hell.

[Headrope]

For grins I put in one of the lifters that originally was in the engine when I got it. Compression came right up to 127 pounds, just about ballpark with all the other cylinders - which was originally the problem I was trying to diagnose. The true test will be to see if it still smokes. If so, rings. If not it was likely a collapsed lifter the whole hee-haw time.

I have another engine ready to go, so am not too worried about this one. It really seems like the lifter just got stuck in its bore. Hopefully I'm right and can flush the engine clean with a bunch of oil changes, a couple of filters and a nifty trick that I should really patent and sell some day.

[TylerCharger69]

i dunno.....with that lifter ground down to nothing....that tells me the valve was stuck  closed,  and all that pressure having no place to go, probably damaged the rings on that cylinder.   It's happened to me....but what happened was my camshaft lobe was ground down to nothing as opposed to the lifter.   Yes...stuck valve!!   And   I lost all compression in that cylinder because my valve was stuck closed  and DID indeed damage my rings.    Engine needs to come apart!!!

[Headrope]

I drove the Charger today for almost two hours!!!!

Before starting her up I changed the oil (not that I could find anything wrong with what was in there). I even cut up the filter, so that I could try and see what was in there: nothing out of the ordinary.

Upon initial startup the engine still smoked out the right side tailpipe. Figuring that was it, my lifter "fix" wasn't the solution, I decided to go for a drive anyway; the engine still ran and - well, damnit I wanted to drive the thing. The smoking stopped before I was able to back out of the driveway. The clouds even parted. Really.

I've since put two hours on the motor and everything seems okay. I'm hoping this to be my final post on this thread, so want to thank now everyone who has helped me out. I'll be back if I'm wrong.

NOTE TO ANYONE FOLLOWING MY ADVENTURES: I'm being stupid with my motor only because I have another engine ready to drop in. I truly appreciate everyone's feedback as I've worked through this process.

[Chryco Psycho]

 

[Headrope]

Well...  I have another post: a good one.
To celebrate what seems to be me finallly having my Charger back after more than a year of fussing with it I took a buddy out to a bar. When I rumbled into the place I had three guys asking what type of car it was, etc.; the fifth guy knew - or at least read the script across the taillights as I backed in.
Two drinks into the night I decided I should probably pull the coil wire, since I didn't have the hood back on my car yet; that's all I needed was a drunk to mess with me by removing the most critical component of the entire ignition system. In doing so I broke the terminal inside the boot (what are those things called anyway?). I put it back on figuring the spark could arc. EVEN THEN the car started back up and ran awesome.
I'm still hesitant to spike the ball on this and do my touchdown dance, but if nothing else my day of bliss is a true testament to Mopar engineering. If I can enjoy a car after replacing a hydraulic lifter that ground down enough to expose it's core, and despite a broken coil wire, I can do anything.
Coming soon: pictures of hot barmaids posing in, on and around my car - I hope.

[firefighter3931]

It'll be interesting to see how long it runs....those metal particles are somewhere. I'll bet the oilpump is full of little shavings and the rotors are scored up pretty good. Best of luck with it.

Ron

[8WHEELER]

  it is very hard to get all of the debree out of the engine after a breakdown like that.
It is still a first for me to have a lifter ''only'' problem, cause no compresion and tons of smoke 
But good luck 

Dan

[Headrope]

It'll be interesting to see how long it runs....those metal particles are somewhere. I'll bet the oilpump is full of little shavings and the rotors are scored up pretty good. Best of luck with it.

Ron

Good point. I'll check the oil pump.
Heck, as easy as the oil pump is to get to (yet another testament to Mopar engineering) I should replace it just because.