Please go to the main pic site to look at the high-res files. This is a shot of the rocker arm roller on cyl 3 exhaust. You may ask yourself, why would I be having the valve cover off? Well, I was changing the timing chain tensioner plunger. To "set" the tensioner you have to "release it" by pushing on the guide. To do that you have to take the cover off. So, while inspecting everything, I saw this: And this: Again, please look at the high-res versions. You will see indents on the roller and cracking on the cam lobe. Now, for the details. Dec of '05 build date. 61,8xx mi on the motor. Oil and filter have been changed every 5k to 7k miles. Always synthetic. No additives. I have not raised the rev limiter. Car is a daily driver. Yes, I drive spirited, but not crazy. Never tracked, nor auto-x'd. The Dragon/twisties is as rough as it has gotten. I will be adding this to my unexpected list of mods, out of necessity.
I don’t have the greatest monitor, but I really can’t tell if it is cracks or debris pressed on the lobe. Go ahead and remove the rockers for a better look. I’ve seen at least 20 OEM camshafts in the past few weeks and have not seen even one minor flaw. BTW, there’s no need to manually release the tension plunger, oil pressure will set the correct tension seconds after starting the car.
Thanks for the info guys. I figured that the pics were not going to be good, nor not much help. Here is a closeup/crop. . Good to know for the tensioner. I was just going "by the book". Kinda glad I did, or I would not have see this. It's good news for you too. I'll be in contact to buy a "new" cam from you.
Here are more pics. Cam is out. Now I just need to order the sprocket bolt. Any good places? Suggestions are welcome. I'm not sure what happened during the upload. The pic hosting site must do some sort of "processing" to them. My hands are not that read and they were not that dark when viewing on my PC. Cyl 1 intake 1. Cyl 1 Exh. The rest are Cyl 3 Exh. Different angles. Tried not to get the reflection from the flash. The rocker roller is pretty much the same as the first shots. Just a reverse image of the lobe. Again, I encourage everyone to view the high-res images. You can see the detail much better. Esp in the dark ones. If you are having issues getting the high-res to come up, hover your mouse over the image on the right and click Original. Also, does RealOEM have the part number for the the rockers with the metal retaining cups?
my first guess would be lack of oil, but with what you have said that should not be the case. but any big leaks or are you burning oil? do you check the oil often from change to change? Other theory would be a bad cam casting, which made the rocker fail also. have you ever had the cover off for any other work? is this the first time you have had it off in 68K miles? if so it could have been there since day one. that is a stock cam right? Real OEM should have any part number you need. and you might be able to find these used. I think i might even have some around. no cams, but i think i have rockers. Chad Detroit Tuned
Correct. I check the oil fairly regularly. It uses about 3/4 of a quart at the 4k mark. Top it off and then change it at about 5500 to 6500 miles. No leaks. The driveway is concrete and would show. This the first time anything has been off of the engine. With the exception of the SC. It was off to check the oil levels in it and water pump. That was done at about 48k mi, before going to CO last year (about July). So, yes, this is a stock cam. Call me paranoid, but I always replace things before they have a chance to fail. The whole ounce of prevention thing...... Just like the belt tensioner asm'ly. Replace before making that 4k mi trek. My thought on the rockers was this. I have a set from a "donor", but some of the plastic caps are cracked. I was going on what someone had said about the late '06 models having the metal retainers. I didn't know if the number had been updated in the online catalog. So, I was going to just get a whole set. At least the exhaust side. Quick question, the donor rockers are of a different (casting??) number, however, they look to be identical. Does anyone foresee any issues if I only use the one rocker to replace the failed #3 exh piece? Chad, do you have a sprocket bolt?
i do not have a sprocket bolt. why do you need one?? you can just reuse the old one. use a dab of lock-tite. i am sure i can order one from the dealer, or find one at the bolt store down the road if i had too. give me a call if you need help. as for the rockers, from what i have seen in cars they are all the same, but without doing some research, i could not say for sure. and i am not always looking for small things like that, so i could have missed a new small change. normally if the item is working correctly we are moving on the get to the item that failed. Chad Detroit Tuned
I also looked at Real OEM and put my vin to look the rocker arms and it doesn't say anything about plastic or metal options just intake and exhaust. i also looked at what is on the shelf and all look plastic. EDIT: But this photo i found here in the MA Gallery shows metal.
Dealers have to order it in from the WH's. All said that it would be 3 bus days to get plus them getting it to me. it was just wishful thinking that you would have a "stock" of them for changing them out when doing head/cam swaps. It is on recommendation (individual and dealer) that the bolt is a one use item.
New rockers come with the metal hydraulic valve lash adjusters. Myself, Mike at Mynes Performance, and recently Nitrominis, have been attempting to locate a source and/or fabricate more robust new retainers. BTW, I have used rockers and new camshaft bolts. The reason I recommend new bolts is because I’ve measured bolt stretch on a used one. Tell us about the tensioner problems you were having? I have lots of ideas but need more details.
Me? The past few weeks have been crazy. :eek6: Um, yes, the whole thing that got this started was a rattle that was on the passenger side of the motor. After lots of reading and deductions, I cane up with the tensioner piston/plunger to be of fault. Upon changing it, the rattle has gone away - or so it seems. I could not leave the car in the spot that I changed the tensioner, so I had to re-assemble everything and move it. That's why I think that the tensioner resolved the rattle issue. Now, on to oil pressure. I have the Chrono pack that has the oil press gauge in the center display. It reads the same range as it has from new. Cold - roughly 30psi at idle and 60psi + when rev'd or driving. When hot, it's roughly 15-ish and 40-ish when driving. Do you think that it could be my oil-pump? Wouldn't that be a working or not situation? Could it be a restriction in the oil passages? If that was the case, then the other rollers would be more prone to wear, as they are farther away from the center (where the oil comes in), right? This is a "head scratcher" to say the least.
I got everything back together last night. Gotta change the oil and I'll be ready to motor again. :yesnod:
Yessir. Had to do a pulley install last night so I didn't get my oil changed. Got another thing tonight, too. Going to try and get it up and running this weekend.
Morning all, got the oil changed on Fri afternoon and took it for a spin. First impression is: the car needs time to adjust. I didn't have my instructions handy to reset the ECU, so I may need to do that. And no, I didn't dis-connect the batt when changing the cam. Later that night, I went to a friends birthday party. About 30 miles away and most of it was interstate. A chance for everything to "run-in". Well, after dinner, I had a friend that needed some mech help, so I ran home to get tools. This was a spirited drive (non-interstate) and the impression from this was: Wow, much stronger. Still didn't get above 5k to 5500 rpm, but the power was still very noticeable. Saturday, I got a chance to tear up some local backroads. Again, accelerating from 3K rpm is much stronger. I don't think that there is any loss on the low end, mainly because there wasn't much there to begin with. But, there is bit more pronounced effect when you hit the "power-band". Idle is a little different now. Not in a bad way, like rough, just a little more pronounced. I'm going to let everything get happy together this week and will post more before the weekend. I will get a dyno run sched'd up soon and will post my before and afters. Good job WerkinMINI!
An interesting discovery indirectly related to this failed cam issue. theCapn had a core head and valve train purchased off e-bay a couple years ago. He intended to use the rockers from the head, but they were in poor condition. The camshaft from this head was sent to me to satisfy the core replacement requirement. As it turns out it was not an OE cam; first off there is no fault in this, it was just an innocent oversight. I could tell this cam was unique by the weight, lobe size, and color. I thought I had exhausted every possibility in looking for the cam’s identity and I moved on to try and identify the coating at least. My coatings expert recognized the part number as similar to a special Comp Cam he had seen and finally there was a likely manufacturer. Sure enough it was a one-off built by Comp Cams on round stock made of 8620 steel that has this bronze color naturally. When I received the cam specs I could see why the rockers on the accompanied head had been beat up, the profile was aggressive and from the numbers the peak performance power band would have been very narrow, and lift just about maxed out. The lobe separation rendered the cam unusable for reground purposes based on NS profiles. A cam like this entails development effort, master fabrication, materials, and other costs that represents over $1000 invested.:eek6: It’s interesting to me only one cam was made, and details have remained obscure.:confused5:
Competition Cams is one of the best cam grinders in the US. This appears to be an example of one of their customers calling the ball!:lol: I have often posted on forums that anybody can get a custom cam ground. But you still have to have a little knowledge about cams before placing the order. :lol: This example should in no way be representative of the ability of Competion Cams to produce good grinds. Working on the CROWER NS series specification the first thing I took under consideration is the maximum lift and duration that could be used without effecting by way of damaging the stock valve train geometry. From there I worked back wards to find the best combination's to achieve a better performance result then currently marketed cam(s). I do not sell the CROWER NS cams.. You may contact Kieth @ http://werkinmini.com/ a vendor here on M/A about them.