rossman Posted July 3, 2016 Share Posted July 3, 2016 Yesterday while inspecting my cam I discovered what I would call pitting on the rocker pads. The cam lobes show some minor scoring although I can't feel it with my finger or catch my fingernail on it. All of the rocker and lobes look similar. I've seen cam damage from lack of lubrication but this doesn't look the same. I removed the valve cover and checked/adjusted the lash pad gaps per Rebello's instructions at 500 miles but didn't notice this damage. I was primarily looking at the lobes and as stated I checked the gaps at the lash pads not the cam. The engine now has approx 2K miles on it. The cam was lubricated with grease and the oil system was pre-lubed prior to startup with pressurized oil pumped thru the oil pressure sensor port. Could this be a material/heat treat problem with the rocker? Is this something that will just get worse and possibly damage the rest of my engine or can I just run it as-is and keep an eye on it. I apologize for the picture size but I want to show detail... Quote Link to comment Share on other sites More sharing options...
NewZed Posted July 3, 2016 Share Posted July 3, 2016 No pictures of rocker arm pads. Just cam lobes. They don't look terrible. Quote Link to comment Share on other sites More sharing options...
Chickenman Posted July 3, 2016 Share Posted July 3, 2016 Hmm... I think I can see what Rossman is talking about in the bottom photo. Looks like some material flaking off on the rocker pad or galling. Can you take a couple of rockers off and post up some Hi-Res pictures. Also provide more information on Cam specs, Valve spring specs and what oil you are running? And are those rockers genuine Nissan or an aftermarket brand. New or Used? Quote Link to comment Share on other sites More sharing options...
rossman Posted July 3, 2016 Author Share Posted July 3, 2016 You can barely see it in the last picture. I'll pull one of the rockers later today or tomorrow. I really don't know the specifics of the build except what is posted on the first page of my build page. I've been running Royal Purple high zinc synthetic. Quote Link to comment Share on other sites More sharing options...
NewZed Posted July 3, 2016 Share Posted July 3, 2016 I see it now. Worth more examination. Quote Link to comment Share on other sites More sharing options...
Leon Posted July 3, 2016 Share Posted July 3, 2016 That doesn't look too good. I'm not a fan of Royal Purple, can't explain it scientifically but they don't have a great reputation. Try switching oils to whatever your cam grinder recommends (I run Brad Penn based on Ron Isky's rec), maybe consider replacing the rockers with new ones. Were they resurfaced or new? Quote Link to comment Share on other sites More sharing options...
torynich Posted July 3, 2016 Share Posted July 3, 2016 It's called "spalling" if you want to do some research on it. 1 Quote Link to comment Share on other sites More sharing options...
Tony D Posted July 4, 2016 Share Posted July 4, 2016 ^^^ I agree, from what I could see in the photos, it looks like spalling of the face, not galling. They're two different things caused by different forces. Were the rockers new, reground, or ??? Spalling is usually overpressure from an insufficient depth of heat treat. if they were resurfaced, it's possible they were ground almost through the heat treated hard surface and are now flaking/spalling from applied pressures. Oil may be contributing, but changing oils won't really change anything if this is the mechanism at work. Spalling/Brinelling happens independently of lubrication. The issue appears in the rocker, but will affect the cam eventually (as you are starting to see.)What is Rebello's assessment of the phenomenon? Quote Link to comment Share on other sites More sharing options...
Chickenman Posted July 4, 2016 Share Posted July 4, 2016 Yes, you are quite correct about the spalling effect. I couldn't remember the correct word and galling was as close as I could remember. Similar to the flaking that you see on rod bearing from over pressure and the resultant metal fatigue. Usually due to detonation. That's why I was asking about who made the rockers and spring pressures. I think it would be very worth while contacting Black-Stone Labs and getting one ( or more ) of their oil analysis kits. Then send the oil in to Black Stone and see what it reveals.If you are not running a Factory PCV system... make sure you tell Black-Stone that. It will help with the analysis. The oil analysis will give important data on the wear, of lack of wear, on frictional components as well as a detailed analysis of how your oil is performing. Turbo engines can be very hard on engine oils, including Synthetics. . http://www.blackstone-labs.com/ Waiting on those Rocker pictures. Try and remove more than one, especially if you have a good and bad rocker. Send the pictures to Rebello as well to see what they think. Note: Regarding pictures; Try and use a good Digital Camera with Close-Up feature. Turn off the flash and use natural lighting. Flash often causes reflections that can hide fine details. . Quote Link to comment Share on other sites More sharing options...
Tony D Posted July 4, 2016 Share Posted July 4, 2016 I have an LED Ring Light for my Nikon Coolpix 7000, and take metal fatigue and failure analysis photos all the time for work. First time I sent in photos to engineering they freaked because on a 12mp macro photo (square, 1:1) of a failed rotor stud they could see grain and beaching marks... Then they called me because the follow up photo was a 1X, 10X, & 100X photo micrograph series taken with a USB Microscope I bought in Taiwan for $60... Quote Link to comment Share on other sites More sharing options...
rossman Posted July 4, 2016 Author Share Posted July 4, 2016 Sorry, been watching the tour all morning. Cavendish pulled it off again! It was a great photo finish! I'm no materials expert but It certainly looks like spalling. I've seen spalling on machine bushings that were used on a custom made fatigue crack propagation machine. We were seeing loads much higher than expected. The bushings were redesigned using harder material; solving the problem. I don't believe there are any good rockers but I'll verify. Pictures will be taken with the almighty Nexus 6 camera...that's all I got I may take one to work for photos if I can't get a good shot of it. We have a nice high-magnification camera there. Thanks for the feedback guys! More later... Quote Link to comment Share on other sites More sharing options...
rossman Posted July 4, 2016 Author Share Posted July 4, 2016 (edited) Here is the best shot I could get of #4 of 12 from the front. http://forums.hybridz.org/gallery/image/33849-spalling/ Edited July 4, 2016 by rossman Quote Link to comment Share on other sites More sharing options...
Chickenman Posted July 5, 2016 Share Posted July 5, 2016 (edited) Oh crap!! That's not good at all. Stop running the Motor immediately!! Those rockers are failing. It does look like those Rockers were reground... and a bad job was done. Notice the grinding marks on the pad. Probably went through the Hard Layer coating as Tony mentioned. I'd contact Rebello and see what they can do. My advice. Buy all new factory Nissan Rockers. Send the Camshaft back to Isky and have it examined and Micro-polished ( if possible ) . Get an oil analysis kit from Black-Stone Labs and find how much worn metal is in your oil. They may be able to differentiate from soft Iron and Hard iron. I'm expecting the Iron PPM will be way up there... Edited July 5, 2016 by Chickenman Quote Link to comment Share on other sites More sharing options...
Chickenman Posted July 5, 2016 Share Posted July 5, 2016 (edited) Large image of Rocker Damage. Click on thumbnail to enlarge. Edited July 5, 2016 by Chickenman Quote Link to comment Share on other sites More sharing options...
Chickenman Posted July 5, 2016 Share Posted July 5, 2016 After getting the oil sample, of course drain all the oil. Inspect for any metal particles. Cut the filter apart and inspect filter medium. And of course if you have a magnetic drain plug that will tell a lot. Rocker pad material is very hard. It will eat everything alive in short order if it gets in your oil system. The oil filter is a Bypass system on these cars. Only a percentage of oil gets filtered on each pass. That's normally fine for regular dirt particles, and soft iron ( wear from rings ) but Tappet material, or Rocker Arm Pad material is extremely hard and will embed itself in the soft Babbit of con rod and Main bearings very quickly. Not good news I'm afraid... Quote Link to comment Share on other sites More sharing options...
rossman Posted July 5, 2016 Author Share Posted July 5, 2016 (edited) Yep, #5 too... Unfortunately they all appear to be like this. Edited July 5, 2016 by rossman Quote Link to comment Share on other sites More sharing options...
rossman Posted July 5, 2016 Author Share Posted July 5, 2016 All of the spalling is happening on the trailing edge of the pad. Seems like the leading edge would be the most likely place to fail since I'd think it would see more impact type loading. Anybody have insight on that? Quote Link to comment Share on other sites More sharing options...
Tony D Posted July 5, 2016 Share Posted July 5, 2016 Insight? "Reground Hardened Pads are not always a good alternative to new." Penny Wise, pound foolish.An L-Series Cam Setup has never been cheap. Cutting corners can bite you in a bad way...This appears to be one of them. Quote Link to comment Share on other sites More sharing options...
Chickenman Posted July 5, 2016 Share Posted July 5, 2016 I have a bad feeling a complete engine tear down is going to be required.... This is not simple wear. This is hardened metal chips flowing through the whole lubrication system. Sorry man. That sucks big time. You " may " have gotten lucky, especially if you have a Magnetic drain pan. But only sure way is a thorough inspection of complete engine. If you do start finding metal chips in oil filter pleats, embedded in Rod and Main bearing material etc, there are certain additional steps that should always be done with this type of failure. 1: If you are running an Oil cooler. Throw it out. Metal chips will get stuck in turbulators of engine oil tubes and in corners. Even Ultra Sonic cleaning will not get them out. 2: Oil cooler hoes. Toss them out if they are AN with liners. The chips get embedded in the hose lining and can not be properly cleaned out. Some will remain, and eventually work their way loose and go thru the bearings. Hard lines ( Metal Tubes ) can generally be flushed out safely. 3: All oil passages in engine block and cylinder head should be cleaned with Rifle brushing ora a similar method. That means removing all oil passage plugs. High pressure solvent blasting after cleaning with the Rifle brushes. Head can be Ultrasonically cleaned. So can block if you can find a Tank large enough. 4: Turbocharged? If using AN hose for lubrication and drain, throw out the hoses. Chips can embed them selves in that hose liner as well. Check the CHRA and blast clean with lots of solvent and air. Clean any restrictions thoroughly. Ball Bearing CHRA's may need to be pulled apart and checked for debris in bearings. Journal bearing are generally a bit more robust. 5: Oil pump will of course have to be pulled apart and checked. Don't forget to thoroughly clean all oil passages in Timing cover Please feel free to Chime in if I've missed anything... GL. Quote Link to comment Share on other sites More sharing options...
rossman Posted July 5, 2016 Author Share Posted July 5, 2016 Insight? "Reground Hardened Pads are not always a good alternative to new." Penny Wise, pound foolish. An L-Series Cam Setup has never been cheap. Cutting corners can bite you in a bad way... This appears to be one of them. Yah, that part I get very clearly I was referring to the failure mode of the pad. Why the trailing side of the pad and not the other. Quote Link to comment Share on other sites More sharing options...
Recommended Posts
Join the conversation
You can post now and register later. If you have an account, sign in now to post with your account.