Rocker Arm spring (?)

[Pomorza]

Hello all

This past tuesday I turned the Z on and drove to work per usual. For some reason something just didn't sound right, there was something coming from the top end that just wasn't there before. I figured today I'd pull the valve cover and take a peek under there and see if there was anything wrong. Long and behold the number 9 valve rocker arm spring was half off (Pic included). I took it off, inspected it thoroughly and reinstalled it back to its normal and functional position. So two questions, one, how common is it for these to fall off. Its not like I was racing the motor (I rarely ever rev over 5k and floor it occassionally)? Should I be worried about this, is there anything I could do to help this not happen again?

I took a nice long look at everything else on the top end. All the lashpads look good, valves look good chain is under tension, cam is well oiled (and hot as hell as I did this right after a drive). I didn't check the valve clearence but will do so after I acquire a remote start button (so I can turn the motor over without the key).

Thanks all

Jan

P.S

Sorry about the bac picture quality it was taken via a phone, a non smart phone.

Edited November 9, 2012 by Pomorza

[LeonV]

Those can come off in high-rpm situations, but lower-rpm situations aren't out of the question. Checking valve lash should be your first order of business.

BTW, you can turn the engine over by putting the transmission into high-gear and simply pushing the car. This is how I do my valve adjustments, no tools or switches needed.

[71Nissan240Z]

You should buy new retainer springs

[siteunseen]

I too rolled mine in 5th with the plugs out and it worked good but for $15 dollars at Autozone the trigger style remote starter is great. When you point the lobes up remember the motor leaning to the passenger side. I did mine straight up the first few times before I realized they kept needing to be adjusted.

[Pomorza]

Guys,

An interesting thought ran through my mind earlier this evening when I was driving home. I run a lower temp thermostat (160) in the Z as well it gets hot here in the summers. Now that its cooled off (mid 40's) the Z rarely ever runs above 160. Could the lower running temp affect the valve adjustment? I adjusted the valves about a year ago (maybe less) but that was before I swapped tstats.

Thanks

Jan

[Oiluj]

More knowledegable members can correct me, but a 30 degree temperature difference is unlikely to make any discernable dfference. The valves are about 5" long. Unless I made a math error, (possible), for stellite, the expansion rate is 0.005" micro-inch/inch/degree F, or a total of 0.015 micro-inches. Not much appreciable change in length...

Source: http://stellite.co.uk/Portals/0/Stellite%206%20Final.pdf