Question on rocker arm shaft installation

[x98boardwell]

When I am trying to create the best seal possible for this shaft not to leak what would be the steps to take to ensure this outcome?

1) Do I not oil/lube the inside of the rocker arm so the oil doesn't get on the shaft as it slides by? And then, just oil through the tiny hole in the rocker arm after the fact?
2) Should I put any kind of sealant on the inside bore of the cam housing so once the shaft passes through the rocker arm it is introduced to some ______ (fill in the blank) which will help seal it better than being just dry?
3) The RSR seals I have used in the past and to be honest don't seem to help all that much.. I was told to tighten the shafts more than factory specs which will help with leaks. Thoughts?

These are a few of the things I am thinking about and wondered what people thought.

Here is the motor going back together after the parts were at Competition Engineering for a few weeks... some progress being made.

[4sd911]

Did you check with Competition Engineering on this?
"Competition Engineering - CE's war on oil leaks"

[docrodg]

DO oil the bushing on the rocker arm.
DON'T put sealant on the rocker arm.
DO use the RSR seals.
WHen you tighten down the shafts, once the bolt starts to snug up do not hold the nut anymore, it should expand and be held by friction alone. Torque to spec.

IF they leak it is most likely due to damage in the shaft bores on the cam housing. Inspect carefully and measure prior to rebuild. If worn out then you will get a leak no matter what.

[lindy 911]

I used RSR seals and mine are dry. Make sure the bore is clean and dry. I made a polisher for my cordless drill with a piece of 3/16" aluminum tube and taped a piece of emery cloth to the end. I then rolled the emery cloth around the end of the tube to form a drum that fits into the bore of the cam housing. Turn on the drill with the other end of the tube chucked up and use the emery cloth drum to polish the bore. I also used a screw with a nut to hold the rocker shaft in my drill press so I can spin it and use the same emery cloth to polish the shaft. Seems to work well...

[x98boardwell]

You know, Walt did tell me he had some info on his site and I guess I just forgot. I will look into it. Thanks all for the help. Maybe I'll give RSR seals another chance.

Regards,
Bryan

[Alan L]

Originally Posted by lindy 911

I used RSR seals and mine are dry. Make sure the bore is clean and dry. I made a polisher for my cordless drill with a piece of 3/16" aluminum tube and taped a piece of emery cloth to the end. I then rolled the emery cloth around the end of the tube to form a drum that fits into the bore of the cam housing. Turn on the drill with the other end of the tube chucked up and use the emery cloth drum to polish the bore. I also used a screw with a nut to hold the rocker shaft in my drill press so I can spin it and use the same emery cloth to polish the shaft. Seems to work well...

I do the same, but I use 1200 Wet/dry - ie real fine hone in the housing bore. Clean the shafts up nice with same if needed. I have managed to also use 2 O rings instead of RSR rings.
Of the several jobs I have done this way, none have leaked. I torque them to spec only . Over tightening can really only swell the housing and make it harder next time. Make sure the bits are completely cleaned - housing and shaft. You tighten/torque ONLY the allen head end.
Alan

[Walt Fricke]

I don't oil the rockers until the shafts are installed. Then I drop Torco assembly lube down whichever hole presents itself (an engine stand pretty helpful for this kind of thing to let gravity do its thing_). And some on each side of the rocker. Then I wiggle the rocker back and forth as much as the clearance (with the adjusters backed all the way off) and side to side until I see the nice red stuff speading. Then on to the next. Seems to work fine. I don't want oil in those shaft bores. It gets there on its own soon enough.

Though, because the ridiculously expensive RSR seals usually get shaved off some on installation, I may resort to a very light lubrication just of the entrances to the bores to see if it stops the shaving. And try a tiny bit of polishing of the bores.

My ultimate goal is to find some used 993 cam housings and avoid this mess altogether.

[Spenny_b]

Bryan,

You could give these a go, from TurboKraft ---> Rocker Shaft Lock Set

Have considered using these on my build, but I/we reckon my engine's only been dismantled once (for this rebuild), the bores are in nice condition, so have given this a pass for the time being (but I am using the RSR seals).

Cheers
Spencer.

[docrodg]

Originally Posted by Spenny_b

Bryan,

You could give these a go, from TurboKraft ---> Rocker Shaft Lock Set

Have considered using these on my build, but I/we reckon my engine's only been dismantled once (for this rebuild), the bores are in nice condition, so have given this a pass for the time being (but I am using the RSR seals).

Cheers
Spencer.

Look nice, but would be even better if they had an o-ring on the end as well up against the flat stop that fit the bore nice and tight.

[mytoy]

OK guys I have a dumb question.

If the rocker shafts do leak what is the negative. I mean that the oil is still in the cam tower and under the valve covers so what is the negative. If there is oil leaks where are they.

The reason I am asking is that I recently had my engine out to fix oil leaks. I did all the areas mentioned, both front and rear crank seals, the triangle and the oil cooler. After putting it back together and adding the oil restrictions I now have a larger oil leak than when I started .

It is coming from between the chain housing and the heads or the cam tower. I am in the middle of removing the engine again to cure this but if I do not have to remove the chain housings and only have to seal the rocker shafts that is a bonus but if the oil leak is not caused by the rocker shafts then I guess it looks like a top end overhaul.

Thanks

[x98boardwell]

yes, they will still leak on either end of the cam towers where the last bolt holds the rocker arms. Also, they will leak through the cam tower towards the cylinders and leak through there as well.

If you think when you put on the cam towers you are only sealing certain areas... not all of it. Everywhere they leak (on either end) you will see everywhere.

Cheers,
Bryan

[mytoy]

So what you are saying is that I may possibly be able to stop the leak by sealing the rocker arms or am I still into taking off the chain cover housings and putting in new seals for the cam as well?

thanks

[x98boardwell]

It could be that seal... and yes, cam nuts have to be loosened to allow the chain to be free along with tensioners and then the seal after sprockets are pulled. You will need to do cam timing again as well... not a fun job.

You could put dye in your system after doing a thorough outside clean and see exactly where it is leaking from. One thing to remember on these engines... most of the time the oil leak may be higher in the motor than you think.

Best of luck,
Bryan

[Alan L]

It will really help to determine if the leak is from the rockers, or the cam seal. Some close inspection and time lying under the engine while running may help. I did have an oil leak from the gap between engine and cam tower. managed to fix it without removing engine. Yes, you can replace cam housing seal with engine in place.
so try and track the source down. Even if you pull the engine, if you do not know the source, you may have the same issue again, as you don't know where to pay particular attention.
Alan

[mytoy]

Thank you for your responses. I appreciate all the help. I can definitely tell you that there is oil pouring out between the chain cover and the cam tower area. It is not a small leak. At first I thought that it was the end of the valve covers that were leaking but upon further inspection I determined that it was further in from there.

Alan if I take the engine out I would then redo the cam tower seals as well as the cam seal and the rockers. This would then allow me to recondition the heads as I think the guides are worn or the valve seals are leaking as well.

I guess the question becomes how to determine if it is the rocker seals? When I take the upper valve cover off I do not see an excessive amount of oil in the tower. This is what lead me to believe that it was the cam seal that is leaking. I also have an excessive amount of oil in the exhaust from the 1,2,3 side. Would this lead one to believe that the rockers are leaking?

Sounds like I will be pulling the top end off.

[Walt Fricke]

The only time anyone would describe rocker shaft leaks as "pouring" would be if one of them got loose and is halfway out of its bore. You'd spot that in an instant when you got the valve covers off.

I once forgot to tighten the three 10mm head bolts which hold the cam to cam carrier (or tower, if you prefer) in place, and carry the O ring which seals the chainbox. The first cam bearing has oil injected into it under pressure. It then gets exits the bearing on both sides. On one side it drops into the clean side of the cam carrier and down and into the oil return tubes, etc. On the other side it moves toward the chain housing, where among other things it lubricates what pass for thrust bearings - the stuff which keeps the cam from trying to get more into the chain box. To do this it passes through the aluminum carrier, which has the three hole gasket sealing the joint to the cam carrier.

My wife noticed the oil hitting the ground as I drove the car from the garage to our nearby trailer.

But that was right after a rebuild, and it was easy to suspect my goof. Easy (for me) to fix, too. Did it in a Walmart parking lot near the Las Vegas race track.

There are other suspects for leaks - the pin on which the chain idler arms sit is pressed into the chain housing, and has epoxy dabbed over its end. But I don't think that pours oil out when it gets loosened and the epoxy breaks.

And there is the gasket between the chain box and the case proper. If that gets torn you can get quite a leak. But there is not much which should make it fail on an engine which has been running just fine (as far as leaks go) for a long time. But this is a rebuild, so I'd review what I did. Maybe you just forgot to tighten some bolts. The housing to case ones you can get to easily enough. To check the cam seal stuff you do need to pull the cam chain gear off.

You can do this in the car. Pull the sheet metal back there. Pull the cover (jacking the rear way up will help with keeping oil where it belongs). Pull the cam nut (or do you have the bolt? Pull that.). Mark everything you can think of, then pull the chain tensioner and pull the gear off. Check those bolts. If they are good, pull them and remove the piece and see what is wrong, having a new O ring and 3 hole gasket on hand. Fix and replace. If you are lucky, the cam may not have changed timing at all. When I did this I had the dial indicator on things, and timing had not changed. Good that I marked the chain and gear and the pin hole and all that so it could all go back the way it had been. Though I was probably just lucky.

[mytoy]

Walt, thank you very much for the insight and the response. It is not a rebuild I just pulled it to reseal the triangle area and the crank seals as well as install the carrera intake. It just pi$$e$ me off that I have a worse oil leak after checking the torque on every bolt and nut and replacing all seals that I could think of. I guess that when checking the torque in the bolts that hold the chain housing to the block that I might have disturbed the cam seal to the cam tower. Also with the oil restriction installed and the increase in oil pressure I guess that exasperates the situation. They possibly were leaking before all this work but with the lower oil pressure they weren't so predominant.

Thank you for the details of the repair. I will probably pull the engine again as I want to check out a few other things out as well as do the repair. Certainly hope that if I do the same do diligence as you with marking everything and trying to hold the cams in place that I do not have a major problem.

By the way I know that parking lot very well from my racing days. Did a lot of repairs there as well.

[Alan L]

If you are still uncertain about the source it is hard to be confident when you do the job again that you will not have the same issue. If you cannot identify it while the engine is running, my suggestion is not to clean the engine down when you strip it next time (I usually solvent blast my engines before commencing a tear down). And as you dismantle each part, look for exterior signs of oil. If it was me, I would be a bit nervous putting it back together unless I felt I had been able to zero in on the leak. I had an issue like this in my 930 after I purchased it. but the engine had some much RTV plastered on it externally it was hard to pick a potential leak. I finally concluded it must be around the cam tower housing - and managed to rebuild this area while engine still in car. But by then I knew which bits to pay close attention too.
That car park sounds useful, and probably covered in oil stains.
Alan

[Walt Fricke]

Gary - I have to confess that I don't use a torque wrench for the 8mm studs holding the chain housing to the case. In part because it is awkward to get at a couple of them with a torque wrench. In part from laziness. I just use a box end wrench.

The 6mm/10mm head three bolts holding the cam seal aluminum piece in place I just torque by hand with a short handled or 1/4" socket wrench. These don't need to be awfully tight, of course. I don't believe the variation in torque which doing things by hand produces from fastener to fastener is going to cause a problem with these two pieces. Not like case/head/cam carrier bolts, where nice even torque is what you want to keep everything lined up just so.

Alan's advice is spot on. I've got a leaking flywheel seal on one of my race motors. I pulled the seal and inspected things. Couldn't see where there should have been a leak. Used some Curil T (which I never use - I was taught to install that seal dry) in case there was a little groove where the case halves meet. Might have slowed the leak a bit, but it is still there. Manageable, because it turns out the major source of the grime was a leak from where the nose and middle transmission parts are joined (this despite redoing that one also). I seem to have gotten that under control with quick dry epoxy, thinking this is kind of crude but if it works -- -.

The fluoroscopic or black light dye trick someone mentioned might be well worth trying, since the motor is in the car and running.

[docrodg]

I love the black light oil kits. Not expensive and easy to use. As long as you don't goose the engine too much and don't drive it before you look with the light it works great. Too much airstream and it blows everywhere.