97grand4.0

Anyone ever see this? Plugged oil galley? Collapsed lifter? Oil is slamming out the #2E pushrod, and a bit from the #3I pushrod, and the others look basically starved for oil . You can see the dry hot discoloration of the #1 spring. Did valve job and lifters, rockers, springs, retainers, pivots.. just 9 months ago and just now pulled the covers. It's really pumping out there, shoots about 4-5 inches high. Like I say the others look almost dry. Must be affecting my oil pressure. It's a gusher. And doesn't stop. in the #2 picture the engine is running and you can see it hitting the scrap of cardboard I shoved in there.

dave1123

Looks like that lifter plunger valve is cracked and not shutting off the oil flow. That means pulling the head and changing that lifter or all of them to be safe.

97grand4.0

$#@!#$% chrysler non adjustable valves and pull the head to do lifters .

I refuse to accept it! My new valve job!
I'm dumping Magic Marvel Mystery Oil in! That will fix it!!
Then Im gonna stick a feeler gauge under the rocker and run the engine to see if longer pushrod will fix it.
Know what's funny? THis guy had the exact same 2 lifters, in the exact proportions, fail on HIS 4.0 stroker.
These are right where the galley comes up from the pump. Coincidence? I think NOT!

97grand4.0

Allright. So I have a plan. I pulled it in the barn and rechecked, same problem. Not oiling all but 1 and that one is a gusher. What's worse, the #1 ex. rocker is starting to munch and taking the top of the valve with it. That's what happens without oil.

After due diligence, I have concluded that when the shop did the valve job and milled the head, this was enough to preload the lifters beyond where they should be, in fact I calculate they are preloaded somewhere around north of .100". Maybe as much as .125". This, I think, may be tight enough that the lifters cannot pump up enough to pump the oil up the pushrod to the rockers. From what I gather from various racing sites and the jeep stroker site, preload should be between .030 and .060 to center the plunger in the lifter.-Lifters, pushrods, pivots rockers bridges and springs were all replaced new with the valve job. Head gasket was a felpro, .045 thick same as OE.

So I found a different machine shop, the guy knew immediately what I was talking about, and I asked if he had the rocker shims that comp cams and others sell, they are two sets of shims, one is .030 and one is .060. All for about $12. He agreed with my thinking and said it couldn't hurt to try, esp if the head was milled. He ordered the set over the phone for me and it arrives in 2 days.

So if I am right, beware when you mill one of these heads, the lifters are fussy about preload and you need to check it. I used the cold lifter base circle check and EO/IC method. When the exhaust opens, check the intake, when the intake closes, check the exhaust. That way you're for sure on base circle. If all the valves are the same height you only need check one. But check them all. Then loosen both cap bolts up and tighten both (because of the bridge that will interfere) and tighten the valve you are checking until you are at zero lash, when you can't move the rocker side to side any more. Then count the turns to go to 21 ft lbs. 1 full turn of a chevy lifter nut which is a 24 thread per inch, equals .060 preload. Now I couldn't find a similar spec for Jeep but the cap bolt thread is 18, which is steeper than the 24 of chevy. so tightening a full turn would put even more preload on the lifter, because you are turning the bolt further, because there are steeper threads. Ah hem. With me? So, one turn of the 4.0 bolt would be even more than .060.
My bolts turn about a turn and a quarter as is, with the milled head.

So we shall see if they start oiling. I think the one thats really pumping may have been so loaded, and so close to the oil pump, that with no other lifters oiling, the check valve broke. My theory so far. Waiting for the shims.

dave1123

The best way to check lifter preload is to place a cylinder at TDC compression and loosen both hold down bolts until the lifters are free, then scribe a line on the pushrods using a scale (ruler) at a height above the gasket surface, then tighten them down to spec. Scribe another line on the pushrod and measure the distance between them. Measuring the turns of the bolt isn't accurate because of the lever created by the rocker arm ratio. You can get pushrods of different lengths or use shims, but remember the ratio involved if you use shims. I'm not absolutely sure, but the most common rocker arm ratio is 1.5:1. In other words if the cam lift is .250" the valve will open .375".

I have a new rocker and pivot here on the bench and the ratio seems to be 1.6:1, but that's just guessing. I know the cam lift is .250" so that would give a valve opening of .400". IDK, I'll have to check that.

97grand4.0

Yeah I know the mark the pushrod method too and may do that, but the turns of the bolt is good as well. Yes the rocker ratio ( fsm said it's 1.6 : 1 for the 4.0) affects the turn method, but, the sbc guys have that all figured out when they say one turn of the sbc (24 tpi) is .060", So I am going ballpark when I say I am over .100, but, thats still way too much and the only cures are shorter pushrods or shims. Shims are quite cheap, And yes, I know that adding a .030 shim does not equal that much less preload, again because of the rocker ratio and the geometry of the pushrod and rocker.
Also not sure that TDC of compression will get both valves to base circle the way that EOIC will?

By the way, did your toasted rebuilt engine have a milled head and if so did they shorten the pushrods? Not that it matters, of course, but something to think about.

dave1123

It stands to reason that if both valves are slightly open at TDC exhaust due to valve overlap, they would be totally closed at TDC compression. You are correct with one turn on a sbc equals .060 on the lifter because one turn on a 24 thread is just over .0416.

Whoever reseated the valves should have measured the stem height and ground them all the same. This is why you should always keep the valves in order when you take it apart. There's more to engine building than most people realize, especially with engines that don't have lash adjustments. Add to that a mill cut off the head and a gasket of different thickness can really screw things up. Maybe a thicker gasket can solve your problem. Just an idea.

Just a thought. If you stacked a .030 and a .060 together....you'd be close to your estimate.

97grand4.0

that would be the pedastal height, not the preload, because of the rocker ratio. But thanks anyway

dave1123

One turn of your 18 thread pitch is .05555555" so.....my mind is cloudy enough right now that I can't figure a 3rd class lever ratio, but you'd be dropping the lifter plunger somewhere in the neighborhood of .075"? and you need more than one turn to tighten the bolt, right? Yeah, I'm guessing .030 shim should be right.

I'd be curious to lay a straightedge across the valve stems to see if they are all the same height.

97grand4.0

I did the straightedge, they were the same height as far as I could see. I think I could see where they milled the ends of a few valves for that purpose.
Yeah my thinking was the same as yours, one turn .075 and it was 1.25 turns, so...and a .030 shim. The guy at Whites said he agreed but couldn't say that was the problem, but he would try it also, "can't hurt anything".

Also I think I'll have a good go today at checking some lengths with the eoic method and marking the rods. Reading more, the pros swear by the adjustable pushrod that is calibrated, one turn = .050".
Shims should arrive tomorrow. Also, am gonna cut an old bridge in half to use during measuring because the dang things interfere with each other when tightening and loosening.

dave1123

The more I read and watch videos on this subject, the more depressed I get. It seems you can't get an accurate pushrod length with oil in the lifters unless you use an adjustable tool to measure the length between the lifter cup at the top of it's travel up against the retainer clip, and the rocker pushrod cup and add .040". The factory preload is supposed to be from .020 to .060. I'm thinking we could make a tool like that by cutting a pushrod near the top end and threading the 2 parts internally, putting a long set screw between them, and adjusting it until there is no clearance, then put Locktite on the screw, take the pushrod out, and add .040" to the length. This is assuming all the valve stem heights are the same! Damn! This gets complicated. According to a video I watched, engine machine shops will make sure the valve stem heights are at the factory heights, but IDK if they ALL do. This was in response to a question about a guy that ground his own valves and they were all different heights. The guy doing the video says they have a bridge type tool that fits over the valve stem and measures the stem height, then you take the valve out and grind the stem to it's proper length. He also brought up the point of spring height where you might have to shim the spring to get the right pressure! I used to do all this stuff, but I've forgotten how tedious it was. Much easier with adjustable rocker studs.

THEN you have to allow the lifters to bleed down before starting the engine or you could risk valve/piston interference.

97grand4.0

Decided to put in a new kitchen sink instead today and eat like a hog. Will update after shims come in.

So the update is, the kitchen sink has 12 mounting screws, and the Moen directions actually lay out a torque sequence similar to the Jeep head. Not quite the same but it looks like they have the flex figured out.
De ja vous all over again.

But, I digress.
One must clear one's mind occasionally with humorous diversion.

97grand4.0

Ok. Goit the shims from crane cam. 16 @ .020 and 16 @ .040. per my micrometer. Oh well, they say .030 and .060, but should work. I set up my magnetic harbor freight micrometer on top of the end of a rocker arm. Mind you the engine is stone cold hasn’t been run in 5 days. Good. So I pull the plugs and go to base circle, which is pretty easy to do since the engine spins by hand readily with the plugs out.

I then tighten to 21 ft lbs and notice that the valve spring is compressing the whole way. Shoot, I think, the lifter is still pumped up. While I am pondering my next plan, ....I notice...that the needle on the micrometer is moving backwards. What is this, I say to myself. As I watch, over about 5 minutes the needle backs up almost 0.100! AH HA! I say to myself. Was the lifter pumped up a bit and then released, showing it's preload in the process?

I repeat the steps, this time the valve spring is NOT compressing, I tighten the lifter to 21 (well you know, tight) and then unscrew it, and immediately the micrometer backs off....exactly .094" ! So my measuring is spot on, and the lifters, as we thought, have way too much preload.

I am about to test each one, and then add the shims and measure again. Dave, what was that optimal spec again? .045? .060? I am feeling it now! I think I dial this right in.

Update: I wasn't doing it quite right, the mic wasn't engaging all the way so reset and rechecked, the #1 exhaust which was the one that was starting to munch the valve and rocker was actually at .155" preload, yikes, (prpbably because the machine shop did NOT cut the valves to the same height after I insisted to replace all the Exhaust valves..) and the intake was at .094. So I added a .060 to each. *NOTE: Crane includes a warning with the shims, if you have bridges, yes we do, you MUST equally shim the intake and exhausts or risk binding or bending the bridges" Got it. *. After adding .060 to each, the Ex is at .080, still out, and the intake came in to .040. Ut oh. Think Ill add another 20 to get the exhaust in and hope the intake is not below .020. ..more..

97grand4.0

So with the dial micrometer I was able pretty easily to measure the preload on all the valves except the #6 cylinder because the setup would not fit under the cowl. So I used the mark the pushrod method and got pretty close but in no way is this as accurate or educational as watching the dial gauge.

Results are that 2 of the exhaust valves were WAY the heck out, at .155 and .145, on 1 and 5 cyls.
The #1 exhaust, which was the one that was grinding metal off the valve and rocker, was one with .155 preload.
Thinking these exhaust valve seats were burnt, and after grinding them the shop left them deep in the head without adjusting the valve height.
All the others were way out too, at about .105 give or take a few. These were brought into .045 ish spec with one .040 pedestal shim.
I now only have to add the shims to remaining 4 cylinders, should be ready to start up after that.

..Almost 800 views on my little thread here and nobody has commented except Dave.
Either am doing a good job or everyone already knew all this stuff. Heh.

97grand4.0

Long story short, after rechecking 3 times, the preload was corrected on all of them to .030 to about .045 with a single .040 pedestal shim. Except for one which took another .020. So 11 of 12 were a .040 and one took .060.
So the engine started fine, not a ton of clatter like I was expecting, and quieted down quickly.
This time 2 additional rockers were getting oil, they were the ones I changed from the Sealed Power back to the ..wait for it..MOPAR.
On inspection, it appears the Sealed Power rockers have the oil hole drilled too far from the pushrod hole, way at the outside of the circle. The mopars are all more towards or at the center. So am in the process of changing out a few more to Mopar.
And yes the one that was pushing a ton of oil is still pushing a ton of oil.
This is a developing story. Check back for updates. Lol.
UPDATE: STILL NO OIL EXCEPT FOR THE 1 THAT IS GUSHING. WAS NOT THE SEALED POWER ROCKERS. LOOKS LIKE I HAVE TO PULL THE HEAD AGAIN AND CHANGE THE LIFTERS. UGH.