I-4 and SV Engine Non-Oiling Rocker Assembly

[Michael Mayben]

Must be the weather? I'm gittin' covered up with phone calls and emails wantin' to know:

...what's that bangin' sound in my motor?

...why do the hydraulic lifters rattle?

...why did I find a broken/bent push rod?

...my oil pump must be bad!

...I rebuilt my engine and now it's stickin' valves.

...a mechanic said I needa valve job cause my vacuum reading is all squirrelee!

...I put a gallon of motornew in tha engine and now the overhaul is no good!

So in this thread we're gonna start from the beginning in explaining/diagnosing the good points and the not so good points regarding the lubrication scenario involved with all I-4 and sv engines. This is gonna be looooong and deetaled so if ya gotta short attention span, go play on the binder bulletin. We're gonna show ya what happens, why it happens, and what to do when it happens ('cause it will happen to you!).

First off...a teezer jpeg. This the infamous sonjascout, whose 345 guts are currently residing onna roller pallet in my shop (and have been for awhile). Pic shows a nine stand rocker assembly, passenger side. This one has the "welded" rocker arms, those require pushrods with a "cup" tip at the rocker end, and a "ball" tip at the lifter end.

All we will be talking about through this thread is the nine stand/welded rocker assembly. That design is the one that gives the most problem on these old motors. We'll have another thread that will show the five stand assembly that uses the "stamped" or "boat" rocker arms, that system was a major cost reduction deal phased in slowly around 1977 or so. But regardless of "which" rocker system you are concerned with, the diagnosis and service process is exactly the same.

 

[Michael Mayben]

Let's continue...

Attached is a scan in .pdf format of the lubrication diagram for all IH sv engines, this is found in every IH service manual if the vehicle platforms were available with the sv engine option.

This same diagram serves exactly for the I-4 engine, just take away the driver side bank of cylinders.

I'm not gonna go through this diagram in detail, but in order to be able to follow through the rest of this thread, you must completely understand how these motors lubricate! So print this diagram and study!

In both engine series, oil which is supplied to the rocker shaft(s) lubricates the rocker arms, the push rod sockets, and the valve tips. Then it's returned by gravity through a single drainback passage at the rear corner of each head, and down through the block in corresponding passages. If those passages clog with accumulated sludge, carbon, small children, etc., the oil return to the crankcase will be impeded. For reference...see this thread posted by ron:

http://www.forums.IHPartsAmerica.co...IH-lifter-rattle-syndrome-what-do-I-have.html

When diagnosing these issues...it's very important that no additional lubricant be added or "poured" over the valve train. We must watch the flow (or non-flow!) of lubricant under actual operating conditions, if ya add additional lube, then you just scruud over the evidence and added greatly to the workload.

And...if ya have an extra valve cover available (the more rotten the better), then think about slicing it right down the middle length-wise to make a shield for any oil that's gonna go flyin'. These are not like a sbc which will fling masses of oil everywhere when running without the valve covers. But the valve cover directs the oil return back and down through the return port in the head(s). Without having that in place, then oil will drool all over the exhaust manifold and make a smokee mess! We May have to run the motor with the valve train exposed for observation for 30+ minutes, so plan ahead accordingly!

 

[Michael Mayben]

In order to try and keep all resources regarding the topic of this thread in one place, I'll re-post a document I've prepped (it's in draft form and has not had the jpegs embedded) regarding how to treat these motors that have been sitting non-rotated for several months/years.

The whole idea here is to prevent wiping out the cam bearings during initial dry-start rotation of the crank/cam shafts. Much of the time, the cam bearings in these engines are not damaged going in, but will quickly fail if a proper pre-lube procedure is not performed. All it takes is about three rotations of a "dry" cam that has "stuck" to the babbit layer of the cam bearing to wipe 'em out. From that point on, it's all down hill, no way to go back and "fix" anything except for replacing the cam bearings with new!

 

[Michael Mayben]

And here's worst case...cam bearing material that has taken a hike. And this is just one of the five cam bearings, this is the one that feeds oil to the passenger side rocker assembly.

In my experience, it's nearly always the passenger side (number 4 cam bearing feed) that is affected for some reason, I ain't figgrd that out yet! It goes into failure mode first...but if it's goin' south, ya can bet the driver side is in failure also, it just ain't got there yet!

 

[Michael Mayben]

And here's shot of the cam bearing debris after fishin' it out of the pan, these are the big chunks, not the little stuff that was not easily picked out.

This is only one of several cam bearing failure modes which might be experienced.

Another common scenario is that the babbitt layer simply peels off the base material and looks like a wadded up chewing gum wrapper laying in the pan.

Worst case is that one or more cam bearings actually seize to the journals and then "spin" in their respective bores. In that case, the bore(s) in the block are now badly distorted.

Some would have ya believe that a block in that condition is beyond use. But not true...the cam bearing saddle can be line-bored by a competent engine machine shop and then "oversize" shell o.d. Cam bearings installed in order to "save" the block. No big deal, some extra expense involved though. Key word there is "competent" and will spend a little extra effort in locating the oversize shell cam bearings, and then actually measuring the shells to be installed to determine the proper degree of interference fit for line boring the saddles. Bearings of this type will not be sourced from some localyokel auto parts house, these come from distributors who specialize in supplying engine reman components to the pro engine builders.

 

[Michael Mayben]

Ok, now you've seen the devastation that can result from actual cam bearing failure. But what is the key clue that leads ya to trying to cure the "lifter noise" in the first place? Let's assume for the sake of this thread, that the cam bearings are ok, the cam does not have one or more "flat" lobes, and the motor is makin' decent/usable oil pressure, the compression on all cylinders sez the valves are actuating inna proper manner, a leakdown test sez upper cylinder condition is at least usable, etc. In other words...the "typical" scenario ya have when either a new-to-you rig has been acquired, or ya are dealing with a motor that is not/has not run onna regular basis.

First off...the basic design of the IH lubrication system does not promote great hydraulic lifter stability when it's allowed to sit static say overnight. One or more lifters can simply "bleed down" due to internal condition, and the fact that the lifter galleries will allow drainback of the oil supply to the sump. Once the motor is cranked and running, it takes up to maybe 30 seconds if everything is "normal" for the lifters to harden off and the "tick" noise to subside. In order to do that, full oil pressure must be developed and a major control point for that, is the oil filter element itself. This is simply an IH design anomaly that cannot be compared to other engines! And it's not really something to worry about or try and correct, it is what it is and does not create any issue other than being an annoyance!

This drainback deal is also made worse if the rig is parked so that the nose is uphill say inna drive way, parking lot, campsite, etc. If parked nose down, the lifter tick May never be experienced! And this sitch can/will occur even with new lifters freshly installed. Just get used to it and move on! At least it's an audible indicator that the engine is running, ya have oil pressure/flow, and it's an endearing quality!

On the other hand...the problem comes in when the tick is heavy and sounds like a hammer whackin' an anvil! And the noise won't subside or go away after several minutes of operation. Now we're talkin' the reason for this thread!!!

Folks with experience in dealing with chryfordrolets motors will say it'sa "rod knock", or it'sa "cracked piston" and try and sell an engine overhaul. Those are the folks ya wanna run away from 'cause they have no experience in dealing with IH junkiron!

So...if ya have heavy lifter knock, I'd first change the oil! And the filter! Just put anything in there that is fresh. The most common "cause" of the lifter bang I've found is an oil filter that is past it's useful service life for whatever reason!

Once you have completed your diagnosis and have verified proper rocker assembly lube...then change the oil again using whatever you decide to run in the motor onna permanent basis. Same for the oil filter, I'll now use only the wix filter, the baldwin filter, or the purolator "pure one" series as I've verified the effect those filters (haven't actually verified the baldwin....yet!) have on hot oil pressure, and the resulting reduction in lifter tick "time" inna cold start sitch after an extended non-running period.

 

[Michael Mayben]

Continuing on...here ya see the entire rocker assembly removed from the cylinder head.

The intake rockers are different parts from the exhaust rockers, they do not interchange with each other. In this particular assembly all the rocker stands are the same part number/design...but that is not always the case. There were at least three different rocker stands produced, each slightly different from the others. The important thing is...that the stand which passes lube oil from the cam bearing, must have the "oil hole" present, and that hole must not be blocked with sludge/carbon.

And the rocker assembly must be assembled in the correct order shown, otherwise it cannot actuate the valves correctly and severe damage will result.

By the way...these are the rockers referred to as the "welded" or "cast" rockers. They dam sure ain't a "cast" part, and they are formed from a complex sheet metal stamping that is folded and then spotwelded, the pushrod ball and the valve actuator pad are then pressed into the piece, then a bronze-lined steel bushing is pressed in. These rockers were supplied to IH by federal mogul.

Both the ball and the valve tip are hard faced for wear resistance, but must constantly receive lubrication when the engine is running.

 

[Michael Mayben]

This shot shows the bottom side of the rocker assembly.

In this example, all rocker stands are the same p/n, and all have the oil passage incorporated in the design. But only the stand that is labeled carries oil to the rocker shaft so it must always be installed in the position shown.

The bottoms of all the stands must be flat and machined exactly the same height in relation to the centerline of the rocker shaft itself. We sometimes see where shadetree folks have attempted to grind off the bottom of those stands in order to "drop" the rocker assembly closer to the head. That's a juryrig workaround to add additional "preload" to the hydraulic lifter in an attempt to quieten a whackin' lifter. That will not work and results in a wasted rocker stand! Just ask sonja or tren and Chad long! Both experienced that disease!

 

[Michael Mayben]

Here we have the individual rocker stands removed from the assembly in order.

Notice the "l" shape to the bottom pad which seats against the head surfaces. In some cases, you will find some of the stands do not have that pronounced "l" shape, but are rather triangular. Those stands will never contain an oil hole that has been machined in.

Those "blank" stands May be used in any position on the assembly except...the "oiler" position...and the third position from the front of the rocker shaft. The "head" of a head bolt in that position will prevent the stand from seating against the head inna proper fashion. So a "cutaway" rocker stand must be used there also. And that is the third type stand sometimes found, it's made just like the oiler stand, but has no lube hole!

Bottom line...ya must pay attention to the correct assembly sequence here, especially if mixing and matching used parts!

 

[Michael Mayben]

Here's the entire rocker arm assembly taken down to component level.

Every component shown here is available today in either a new part, or remanufactured piece. Same for the corresponding push rods.

This single rocker assembly is used for all I-4 (both 152 and 196) engines, along with both sides of the 266, 304, 345, and 392 apps. The oiler stand must be in the the third stand position from the rear of the engine.

When the rocker assembly shown here is flipped end-for-end, it becomes the driver side assembly for any sv engine app. The driver side oils in the third rocker stand from the front of the engine.

And yes...there is only one cylinder head assembly used for each sv engine displacement, they interchange side-to-side, there is no "left" or "right" head.

Confused??

 

[Michael Mayben]

Closeup of the bottom (important side!) of the oiler stand.

Ya can't see it very well in this pic...but that lube hole is completely blocked with sludge and carbon. The rocker shaft that was fed from this particular stand received no lubricant for a very long period of operation. The shaft ya see in this pic is not the badly worn shaft that was fed (or not fed) by this stand!

In addition to showing severe wear at the shaft/rocker bushing interface, the shaft pivot point itself was heavily scored and had actually turned blue from overheating/lack of lube. And the entire bushing had disappeared from the rocker arm also.

 

[Michael Mayben]

This is a shot comparing a "useable" rocker shaft with one that is badly damaged from lack of effective lubrication.

It's hard to see in this pic, but the pivot points on the lower rocker shaft are worn down severely. That one is not useable except as a cheater bar!

If ya tried to re-use that shaft...and a rocker with a worn out bushing, the resulting "slop" in the valve train for that cylinder will throw the valve timing off by a significant amount as compared to the rest of the cylinders. No way to make that engine idle crisply. And no doubt the valve train would be extremely noisy.

Again...it's stuff like this that folks swap carbs, ignitions, chase "vacuum leaks", etc. In trying to improve idle quality and drivability, when in essence the root cause is poor valve train control, same as a cam with lobes that are worn beyond spec or going "flat".

 

[Michael Mayben]

This shot shows a "rebuilt" or repaired rocker arm of the welded type.

This one has had a replacement bushing installed (which obviously was not a new one and is in itself badly worn!), and then tack welded in place!

Also, ya can't see the badly worn "tip" which engages the end of the valve stem itself to push the valve open at the correct point in time. Those tips are hard-surfaced but will wear quickly if not constantly lubricated.

I have several non-useable rockers where someone pressed the tip out, tried to regrind the surface, and then put a shim under it and pressed back in. All in the name of "pre-loading" the lifter to attempt to eliminate the lifter noise. Needless to say, that doesn't do anything when the cam lobe itself is flat, the lifter is stuck in a collapsed mode, and the push rod is bent! All caused by lack of lubrication!!

 

[Michael Mayben]

We're almost to tha point whee we can start fixin' stuff, but let's look at one other "diagnostic detail"....

This pic shows the top of either rocker shaft. Notice the smaller holes as compared to the larger holes.

The small holes at each rocker pivot point must be oriented in the up position when the assembly is installed to the head.

Once the rocker shaft is completely filled with lube oil from the cam bearing/journal feed, it begins to stream from each of the eight spit holes and into the rocker shaft bushing.

See the small "notch" at the end of the rocker shaft? That is the indicator that the shaft is correctly oriented when re-assembled. That notch is present at both ends of the shaft. Always verify correct assembly before installing the rocker assembly, which is...notch up!

If the rocker shaft is installed upside down, then oil simply drains away and an insufficient quantity will emerges from the bushing area to drool onto the pushrod cup end, and also down onto the valve tip interface. The oil is channeled through that groove formed when the rocker stamping is folded together and then spot welded.

And both ends of the rocker where the hard face tips are inserted must be clean and sludge free. Ya gotta see daylight if ya look at the tips! That is the only way oil can reach the hard tips!!!! Very simple piece of engineering!

 

[Michael Mayben]

Now let's take a quick look at a typical I-4/sv cylinder head.

We already know that oil is delivered from the cam bearing/journal inna "timed" fashion to that small port and travels through the oiler stand to reach the rocker shaft assembly.

This pic shows that hole. It must be free of sludge. And the oiler stand must fit tightly against the head at the machined boss. Other wise oil will be released from that interface and never reach the critical component which is the rocker shaft assembly.

Fairly often I find motors that have had some kinda "sealant" applied at that point! That is a definite no-no and a sure sign that someone has been into the motor who did not know what tha hail was goin' on! Any amount of "sealant" applied there is certainly going to squeeze out and block that very small orifice! It does not need any help to seal if the rockers stands have not been previously botchinated!

 

[Michael Mayben]

Once the rocker assembly has been removed from that motor, we can apply the "pre-oil" procedure described in that document I posted.

This pic shows an oil pump drive tool (ihon has those in stock) and the drill motor attached which I use. Ya gotta spin that oil pump with at least 1200rpm to make it squirt, and...the camshaft position in regards to the bearing spithole must be in proper alignment. Again...review that document so ya fully understand how critical that alignment is.

Here ya see one pressure gauge connected to the main gallery where the oem oil pressure ending unit is connected. That allows oil pressure at that point to be read when the drill motor is spinnin'.

The second pressure gauge is connected to an "adapter" I fabbed to allow oil pressure/flow to be measured at the critical feed point in the cylinder head simutaneously.

 

[Michael Mayben]

Here's a closeup of the fabbed adapter for the oil pressure gauge.

It's simply a hard rubber, tapered tip that comes with a mity vac hand vacuum pump tool. It's perfect for doing this!

Ya will need to git creative and fab something similar if ya wanna be able to verify correct oil delivery at that point!

 

[Michael Mayben]

Ok...before we start in with repair, let's see how all that oil in the valve covers that accumulates gets back down into the sump for recycling!

Each head casting has a "drainback" hole at each end. That way, the head can be used on either side of an sv application.

And that hole mates with a similar passage in the block casting, and is sealed by a penetration in the head gasket.

The diameter of that return passage is calculated to allow a controlled return (by gravity) of oil pumped through the rocker assembly, to the oil pan sump.

If that hole becomes restricted because of sludge/carbon, accumulated valve cover gasket debris, rtv/gasket sealers, etc., then oil will not drain out of the rocker chamber under the valve covers! The result?? Much "windage" in that area, aeration of the oil, inability of the upper end of the engine to breathe through the pcv system, valve cover/bolt oil leakage, etc. And in the case of the Scout II oil pan system, a "shortage" of oil being returned to the sump for pickup by the oil pump at higher engine rpm.

 

[Michael Mayben]

Now let's clean out the rocker shaft...one more reason why tha bitch May not be oilin'!

In each end of the shaft, there is a small cup plug inserted. These plugs keep the rocker shaft full of oil whenever the engine is running, that in turn supplies oil to the rocker bushings, push rod tips, valve tips.

But in these old poorly maintained crapball motors, those rocker shafts are gonna be badly plugged up with sludge and carbon accumulation from overheated oil. If those eight small holes can't allow oil flow, then the rocker will actually momentarily seize to the shaft. Or...a valve will seize in it's guide (most common) and hang partially open.

The stuck valve then allows the push rod to jump out of it's proper position, or sometimes the push rod is whacked by the rocker and simply breaks into a couplea pieces and falls down into the lifter chamber. When that happens, the affected cylinder goes dead. Many valve jobs and head gasket jobs have been done for this simple root cause! And doin' a head gasket replacement will do nothing to correct a plugged rocker assembly!

This shot shows a sheetmetal screw having been driven into the cup. Then a small slide hammer witha "puller" has been rigged on the head of the screw and then the cup plug is extracted. Do the same on the other end!

Once both plugs are removed, then the interior of the shaft can be inspected witha light. You will be shocked at what ya see in there!

I clean these shafts either by using solvent and an engine oil gallery brush set, or a 20 gauge shotgun cleaning kit, including the bronze bore brush followed by the swap. Also individually clean each oil spit hole. This shaft must be sterile before installing the new plugs.

 

[Michael Mayben]

Here's a shot of the grungee cup plugs extracted.

The replacement dorman cup plug is also shown, it's a 9/16" callout and should not be substituted for some dam metric "equivalent" plug!!!

The plugs are the "shallow" design and not exactly the same as the oem. That does not matter, what does matter is the nominal diameter. These plugs are designed to be a fairly "tight" interference fit inside the shaft hole, use no sealer when installing these plugs!