Rocker Assymbly & IHON replacment parts

jauringer

jauringer

Member
Well, I was able to take my passenger side (9 stand, welded type) rocker assembly off last night and the news wasn't so good. Nothing was plugged at this point in time, but it was obvious that it had been plugged at some time over the last 39 years.

My rocker shaft is toast. Most of the shaft was only slightly worn. There were a couple spots that would have passed for reuse, but then the rocker closest to the front looked like it was starved bad as the shaft was eaten and scored terribly.

I cleaned up all the stands, arms and spacers last night and went through everything and I was hoping to get a few questions answered so I know how to proceed here.
All but two of the bushings measured out with in spec. One was badly damaged and one was .005 out. (.870)

1. I can get shafts and arms from ihon, right?

2. I had two arms that had a loose valve pad. (not in/out loose, but it can be slightly twisted. Can these be used as is, repaired and used, or do they need to be replaced?

3. The push rod end on all of the arms looked good somehow but there is some wear on all the valve pad. The manual references grinding no more than .010 to smooth the pad but I have not way of measuring the wear correctly. I can feel most of them with my fingernail. Any tricks?

4. Lastly, I will obviously be replacing parts here and the manual talks about increased valve train length. It sounds like I'll need to remove the lifters and clean the varnish so the plunger can move freely in the new spot? Is this correct?


5. I've read about these nylon pellets used to hold the assembly down. My bolts had no nylon on them and are just standard grade 5 black bolts. Am I looking in the wrong spot here?

Considering the situation, I wonder if it's not just better to get a two "new" assembly's from ihon. I would just need to know what else needs to be done since I'll be replacing so many parts.


Thanks a bunch for the help. I'm about to pull the driver side and report back with that damage as well but I imagine it's no different.
Jason
 
Regarding the current availability of all service parts for this rocker assembly you will have to call the shop and give 'em a list to verify. Depending upon what they have currently, we can probably supply a complete set but some of the parts May have to come from my location also.

Rocker shafts are now a big deal in order to find a set of useable items. In some cases we can actually perform a semi-conversion using worn shafts from a boat rocker system, every case is unique.

We do have a supply of individual welded rockers that are useable. We need to know for sure whether an intake or an exhaust rocker is needed though.

A rocker arm with a loose pad is not an issue as long as it's still held firmly in place and it's wear surface is within spec. In fact, I'd not do anything regarding the pad rejuvenation as it's not an issue as long as the valve stem tip is not also worn down or defective.

I'd never remove all lifters, disassemble, and clean! Way too much work for nothing! Simply replace the lifter set and be done.

Don't be concerned with changing the geometry resulting in a "loose" pushrod assembly. That happens when a valve job is done and the machinist does not set it up with the correct "installed valve height" on all sixteen units.

The nylon lock points on the oem rocker stand bolts were part of the "sealing" issue for oil migration. I've torn into many of these engines with the same condition and all kinds of different bolts that do not have an issue in that regard. However, we can supply (in very limited quantities) a set of used/reconditioned bolts of the proper type.
 
Following a 727 rebuild, I saw your were going in for a procedure. I hope all went well!

Thank you for responding as I value your opinion greatly and I'm glad to hear that I've got something to work with. It surprised me to see the shaft being the week point. I would have figured the bushing would be??

I have much better news on the driver side. Everything was in much better condition. The entire set of arms are withing spec and in very good shape. I'm soaking the shaft right now so I don't have a full picture of the condition but I will shortly.

Worst cast scenario it looks like I'll need 2 shafts and a 2 rockers, best case scenario I will need 1 shaft, 1 rocker arm, and 2 shaft plugs. I'll call Jeff and find out the situation.

One other question Mike. The oiler hole in the head that feeds the rocker assembly, is there any way I can clean that out with the head on or is that asking for trouble? They look fine but I'm sure there is a little build up on the walls that could use a cleaning.

Thanks,
jason
 
I'm doing just great medically!

Everything needed for doing this work is contained in this thread:

http://www.forums.IHPartsAmerica.co...I-4-sv-engine-non-oiling-rocker-assembly.html

The oil holes seen in the head do not line up with the actual oil holes in the block. There is a somewhat oval-shaped "offset" at the head/block interface that will preclude douching that orifice. The head gasket seals that small interface, there is nothing needed for cleaning those (those) ports other than when doing a major engine overhaul.

If you actually perform the oil flow analysis as I've described in the linked thread, that process is how the oil flow is determined, by actually observing the flow while cranking the engine and/or using a oil pressure gauge installed in the port to measure the pressure at cranking speed.

In all my years I've never found any engine with the oil ports grunged, the actual grunging is found in the rocker shafts themselves. Secondary grunging is always found on the oil pump pickup screen, many of those are entirely blocked. As long as the liquid is moving through the passages, grunge won't form. But it does form wherever the fluid becomes stationary and is allowed to settle out between engine run events.

The wear points you have found in the valve train itself is indicative of time, lack of actual engine use, and lack of proper engine maintenance,...in other words, the typical conditions we have when these vehicles are not used in a continuous manner. The same issues occur with any engine, not just ihc-produced stuff.
 
Read your oiling thread over and over again. What a great article/walk through....what ever you want to call it. This is definitely not the only symptoms of the po virus I have but it has been the most damaging so far. (well maybe besides the trashed front diff.)

thanks again for the info and I'll talk to Jeff on Monday. Enjoy the rest of your weekend.

Jason
 
Just wanted to update this thread. Ihon just hooked me up with a new passenger side welded type rocker assembly! The new shafts are over sized and the bushings are honed out to fit the new specs. It's looks like I'll be good as new in a few days!

Thanks for all the help.

Jason
 
Good news, my "new" assembly came in today and was able to get in the truck. I've got two good rocker assemblies now so there's no excuse for these not to last the rest of my life.

I'm in the testing phase right now. I've had the truck running for the last 15 minutes or so all looks pretty good for an IH I think.

Two questions to verify that last comment though.

1. The valve tips are oiling like a mofo...way more than the push rod side. It's very hard to see it oiling the push rod tip. Both assemblies are oiling the same in that respective. This very same thing concerned me when I took the originals off but the push rod tips of the rocker were definitely in the best condition so I'm assuming it's just harder to see oil travel there, is that correct?

2. It looks like my rocker stands are leaking out the bottom. Some or all of this May be it just running down the side from the outside and I just can't tell. The one that concerns be the most is oiler stand. What's your advise?

Btw: thanks to ihon for getting everything here so fast.
 
As far as the way the rockers oil, I would say everything is "okay" even if you don't witness a large amount of oil slinging off of that side. If you look at the design of these welded rockers, it makes sense that they would let most of their flow out the long ends. The boat ones are not so one-sided, in my (rather messy) experience.




As far as the bottoms leaking... It's obviously not the best situation, so if you have a serious suspicion about the fitment of your stand feet to the head surface I would say there's no option but to inspect. If you've run it long enough to stir up particles before the next removal, you might even see evidence of a leaking foot in the way of particle traces left between the head and stand.

While it's entirely possible that you did imagine it (the stands do drool oil all over during normal operation) I would at least double-check with relatively dry heads once more. Maybe wrap something around the suspect stands to hold off drool oil a little longer for inspection purposes? Just throwing things out there.

Good luck getting it squared away.
 
I appreciate the feedback.

I can say one thing for certain. My tick, tick, tick, tick, tick has been greatly reduced as of today. I did some more inspection last night trying to eliminate any possibilities. The assembly's are flush on the head (check with a .006 gauge)it does look like the majority of the oil is flowing from the shaft down the stand to the head. I agree with you on the rockers. With the angle that they're at on the head it does make sense that the valve tips would be getting the majority of the oil. After I felt comfortably with the situation, I reassembled everything and installed. At initial fire up and for about 45-60 minutes or so it was louder than it was prior........had my heart beating a little quick! I warmed it up this morning and drove it all day with no noticeable tick at all. Not sure if everything was adjusting to the new geometry or what but it all seem to be good now.
 
Hi jason.
Glad you got her back together and that the racket has been reduced.

You are witnessing a fairly normal oil distribution scenario for these sv's. However we can not see the magnitude of oil flow is sounds like things are ok.
The leakage from the stand base is also normal to the extent that ihon supplied and there is oil pressure so to speak in the stands because they have the bolt extending through the rocker shaft.
 
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