!Broken Valve Spring!

Discussion in 'Fox 5.0 Mustang Tech' started by cobra_weiss, Feb 10, 2006.

  1. Have a question for anyone with an idea.

    I bought a 89, lx coupe with a b303 cam, 1.7 rockers, crane cams valve springs, and stock heads. The car has been sitting for a couple of months. The car was one of my friends and he had it running fine for a year. He then sold the car to someone else that said he ran the car to 6000 rpm when running hard. He then broke a valve spring on the driver side on the #8 cylinder. I can't remember if it is the intake or the exhaust. The same one has broke 3 times now. I am just wondering what could be causing it. If it could be the pushrod, valve, or just over revving it. Any ideas?:shrug:
    Just wanted to have an idea before I dig into it.
  2. I'd say replace the whole setup over there... unfortunately that includes the valve, with a new lock and retainer.

    if you have the stuff to fix it - switching the rod and rocker to the other one might help you eliminate those variables to see if it happens again - but that's still running the edge because you dont want to drop the valve... even it means saving you a few bucks here...

    i'm assuming the seat on the head is good - i dont see you someone can srcrew that up - measure the PR's and compare the vavletrain parts to ensure that some one didnt put in the wrong part somewhere....

    where is the spring breaking at? are they double springs?

    you can do some research to find out the best spring for the cam and setup - but since its the same one over and over - i'd say the problem lies in that area alone...
  3. I agree with the part its something in the area...did someone use different valves, springs etc. Are there any shims under the springs, Seems like maybe someone could have done work to the heads and went out the cheap way or something. There the stock heads right? Maybe someone shimmed the rocker wrong or put in the wrong spring or something...anyways IMO it shouldnt be brought up to 6k rpms anyways but theres still something wrong if the same one broke few times in a row...are they stock springs, double springs? what part broke?
  4. If those Crane Cam valve springs are the conical ones for stock heads that`s the problem.I`ve heard of lot`s of them breaking.

    If these are the springs you have,I would get rid of them.
  5. :Word: do you know which CC valve springs?