Have I compromised a camshaft?

Originally posted on a 986 forum, but I didn't get much of a response, so am cross posting here given that the 996 engine is basically the same as my 986. I just replaced the tensioner pads on my engine and I made a newbie error while disassembling the cams. After reading from several sources and watching videos I went ahead and removed the camshaft cover on bank 2 with the crankshaft 360 degrees off of where it should have been and I didn�t have a tool installed to hold the ends of the cams in place as the cover came off. As a result cylinder 5 was on the intake stroke the intake cam lobes were pushing on the valves and so the end of that camshaft lifted about an inch or 2. I quickly put retainers on the cams to bring them back to where they should have been. Before reassembly I turned the engine to where it should have been and used a tool to hold the camshafts in place while reinstalling the cover. I have since read that the camshaft can break if it is not removed correctly. The engine turns over by hand with seemingly no ill affects. Did I dodge a bullet or is it possible that the camshaft will break once the engine is running?

I think the reason no one has chimed in is because of the risk of saying "they're ok" and you reinstall the engine only to cause serious damage as a result! No one can accurately determine from the picture if the camshafts are damaged or compromised. Hindsight is 20/20, but I would have strongly recommended the proper clamping tools. Jake Raby's Focus On: M9X Engine Assembly video series covers the proper tools and procedure for the job.

WOW....just WOW!

I have always done it with the right tools, and have never forgotten to turn the crank 360 degrees from the other bank. I don't think you have caused damages, but it's not my car and my opinion is not worth much.

I guess anything is possible but being deep into a 3.4l heads doing pads and other maintainence i would think the cams r ok. Even with the tool locked in on ine side and the caps in the other side the cams flex as soon as u remove the covers. The hold downs just even out the pressure across the length. Imo, spining the motor by hand without the hold downs produces very little force in the cams even though they lifted out. The only way to know for sure would be send the cams to the machine shop and have them megnafluxed. This will show if u cracked them.

I broke my Bank 1 exhaust cam by making a small but critical mistake of not updating the sprocket bolts when I updated the sprocket to the newest version (the old ones are longer). Really stupid, and hindsight is indeed 20/20 (as are the pithy comments from the peanut gallery), but if I would have simply had some non-destructive inspection done on the cam after I found the problem, I would have saved a lot of heartache and trouble. Magnaflux or dye pen would have found the incipient crack that I created. https://rennlist.com/forums/996-foru...xperience.html Relevant material in Post #11 I got really, really lucky, as the sprocket flange on the cam broke WHILE the engine was running, fortunately in my garage at idle. I shut it down right away, and luckily did not experience valve/piston contact. I've subsequently replaced the broken cam and the car is running great. ~4000 miles since the rebuild and driving it every day. I'd sure inspect it now before putting things back together. Cheap and easy insurance. My opinion only. Charley

Agree with De Jeeper above, the minute you remove the cam cover the cam is flexing, although when I removed mine, I had a small spring clamp holding the cam end center to the head until I could install the cam holders. I do not suspect that you've damaged your cam. Best of Luck.

Thanks for all the comments and suggestions. While mulling over this situation I thought about magnafluxing. What is the dye-pen and how does that work?

https://en.wikipedia.org/wiki/Dye_penetrant_inspection "Magnaflux" is a brand, magnetic particle testing is a method of non-destructive testing (NDT). Magnaflux offers a dye pen set. https://www.magnaflux.com/Magnaflux/...-Testing-Video Easy to take to a machine shop that has the capability, also can buy stuff online (Amazon etc) We use it at work for castings and forgings for high pressure vessels and fittings. I think generally mag particle is preferred on as-cast surfaces like the unmachined portions of a camshaft, as the surface is rougher and it's harder to get a clean indication with dye pen.