The show so far; compression test shows a read of 30 lb on #4, al others are 160/150.

So I begin the disection with the valve cover. I have a helper turn over the engine and... all the valves pump up and down , no bent pusher rods back there, (as far as I can assess, roling them all /comparing tightness of them beside the other healthy cylinders).

what the heck start it up...

I observed the running engine less its 1-4 valve cover... no ticking ron that side, no observed hang ups it all runs like.. well a well oiled machine which made me question the lack of oil up there.

it seeps, almost unnoticably out the top of the pushrods and trickles down to a skinny pan inder the valvetrain to drip out into a hole in the head.

normal way it goes I guess, but my bro says it should be freely oozing oil onto the rockers and the fiddlebits up there. it far from ooozes... a barely noticeable seep is what I call it.

I put the valve cover on and warmed the engine up and took it off agin to see if warm oil was now flowing.

nope.. just that gotta stare at it for a while to see it seeeeeeping ever so slowy out a micro drip at a time.

please tell me its suppose to do that.

if not how much "flow" should be being pumped up there/how freely should it be flowing back into the head?

oil pressure reads 50lbs...
normal?
something plugged?
bigger problems????

 

if you got 50 lbs of pressure when the engine is fully warmed up that is very good ! i would think there should be more oil flowing out of the rockers myself. if i let mine run for a couple of seconds without a valvecover i have a puddle of oil on the ground! i would take the rocker assembly of and give it a good cleaning. its probaly just got grime in it.

 

Sounds like your valvetrain is well sealed for an FE. Congratualtions. Trust me, if it wasn't getting enough oil it would have caused problems long ago. It's fine. Stick the valve cover back on and dont give it a second thought. Things will change...

 

2nd, I think you may have a problem. It ( the oil ) ought to be noticeably dribbling out from around all of the rockers. Who assembled the engine ? Where there any restricters installed under the rocker assemblys ? are the rocker shafts on right side up ? Where the rockershafts clean when they where installed ? DF, @ his Dad's house

 

Dribble, yes; Oooze, yes, seep, NO.
The low compression might be related to this. Oil is pumped through the lifter and through the pushrod to ooze and dribble out over the rockers.
If the lifter is not pumped up right, is collapsed or pumped up too far, or dirty, it may affect compression.
If the pushrod is plugged - which is commmon for high mileage FE engines, the lifter will still function properly, but oiling will be sparse, if non-exixtent.

Pull and check the pushrods to make sure they are not plugged.

Oiling under full engine pressure also comes up through one of the rocker shaft stands to supply the intenal parts of the rockers, and to drip over the valves. You may want to check the shaft, the stands and all also to ensure nothing is plugged.

Is this a rebuilt motor? Or one that has been running a long time?

 

Guys, the oil comes up through the head, through the rocker shaft, and out through the rockers up to the pushrod end. The other end of the pushrod is down by the cam and gets plenty of oil. Nothing comes up through the pushrod in an FE. NOTHING.

 

That is correct rusty-right on!!! The FE pushrod does not even have a hole in the ends.

 

Well, I sure goofed on the pushrods! It has been awhile since I pulled FE heads, and was going on memory befuddled by lack of sleep.
I got up this morning and read that post of mine, and thought that banjopicker guy sure looks like a dummy!
How embarrassing!
I only do this for kicks and giggles, traveling to work on remoted computers is my paying job, so I'm not working on my truck as much as I wish.

Thanks for the correction, for your patience, and sorry about any confusion.

 

Hey We all are learnin'!! If you stop learnin', you might as well get your headstone!!!

 

30PSI on number 4 cylinder and good compression on the other 7 is likley a burnt exhaust valve on that cylinder. It was good that you looked for mechancal issues that could account for this problem first. Put a teaspoon of light oil in that cylinder and test again. If the number comes up the problem is rings or piston related. If it remains the same it is likley a valve. On an otherwise sound engine, a valve job is in order. Sounds like someone installed restrictors in the head oil gallery. If this engine is a recent rebuild 30-40K, I'd just do the exhaust valve on number 4 and put it back together. I know some here will clench on that thought, but if you just drive this truck and the engine is otherwise sound, I'd do that.

 

Agreed. I'd pull both heads and take 'em to a machine shop to do a full valve job, since the other one most likely isn't far behind.

 

oh the engine came in the truck with a list of "things we did". I like a dip lost the list.
I do remember she said heads, a new cam and a bunch of other stuff. I know thats no help.

I'm going to assume they were smart and replace most of the moving parts in the valvetrain.

yea the pressure is 50 till it gets hot then it bottoms out to 10 at an idle. while I was checking it wasnt quite hot and was still holding 30-40 pounds at aidle.

I did the teaspoon of oil trick it still stops dead on 30 #.

well I assumed the pushrods were hollow as the oil is seeping out the topof the rocker thru a hole right on the top of where the rod sits in its little socket.

i watched it pretty well... I didnt see any oil from anywhere else. when I changed the iol for the first time it was like tar, gunk plugged it may be. I kinda see what they did they redid the top end of the engine but never drained the old oil , just droppe dit in.
I dunno who "repaired" it. before my posession of it.

the gal was pretty "impressed" about what the fixer told her, as he said he put a good set of 428 heads in it... he may have been scamming her who knows.

yeas, 5-8 compression is 160-148-150-160. 1-4 was 150-150-150-30, (or close to it)

I'm in no "need" right now for the truck so I will take my time and remove the heads and the intake, and give the whole train a good cleaning and inspection.
while it is out and open is a new set of lifters expensive? not much sense leaving the old ones that were exposed to that tarrry oil when she had it. I assume everything else can be cleaned and inspected.

I read about those restrictors in the oil holes, so i will look for them, should I remove them?

ahh why would you want to restrict oil there anyhow?


gotta get those exaust mainfold studs removed anyway so it will be better in the end than a patch up job.

 

Add a quart of ATF and let the engine idle for about ten minutes. The ATF is high detergent and will flush a lot of crap out of the engine. You may want to do this every oil change for a few years to keep the engine clean. Lifters are not expensive and a good idea. The restriction in the head oil gallery is OKAY. You will be able to see them when you get the rocker arm shafts off. The oil pressure you have is fine. The manifold bolts come out easier if you can warm the engine first. Put some PB Blaster on them every day for a week, run the engine and work the bolts loose. If you bust one your machine shop can dig it out for you. That intake weighs 77 pounds naked! You should have an engine hoist to remove and install it. When you are ready to reassemble post back, we can help with that as well. I like ARP head studs and will not use a used fastener on anything important. Jegs has a nice stainless intake fastener set.
PS. Taking the rocker shafts off is not as simple as it looks. Get additional instructions!

 

It's not lifters. Even if the lifters are completely collapsed, they'll still move the valves enough to fully charge the cylinder with air while cranking. You have a burnt valve. Probably a sloppy valve job was done last time.

 

I just got the 2 books I ordered that yall recommended..
the chist book and the reid book... pretty good just skinmmin thru em.

that heavy eh?
definitely gonna have to invest in a crane.

is it possible tthe head gasket wasnt put in "right" and just because its not burnin oil or sucking water it still may be a head gasket?
I'm not clear where that kinda breech could be but I'm lookin in the books here.

while I have it off, I might be able to afford a salvaged 4 BBl intake to replace this 2 bBl... for gas issues. Id have to trip over a deal though. the truck I just passed up was a 2 BBl and that made it that much easier to pass on.
if it had a 4bbl intake and a good carb I woulda took it with no thinking.

will it hurt to run this engine in that condition (the one dead cylinder)...?
to move it around, or drive it to get hay ect now and then till its disected...

or will that mess something else up?