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Thread: Valve Spring Life??

  1. #1
    FoMoCo
    Question about Valve Spring Life? How long do they last in a boat? I have been running the same springs for 4 years with a Solid Roller. The boat was spinning 5300(429 BBF) with the first motor for the first 2 years, then I built a bigger motor (460BBF) with a bigger solid Roller, which I am running right now, and the boat was spinning 5700rpms. Here is whatÂ’s going on. I put new bearings in the motor and put it back together for spring, I also installed new Valves in the heads along with a 5-angle valve Job. The boat ran the best it ever had, pulling close to 6000 rpms (Oh Ya I had the heads ported to). That only lasted for 2 trips to the lake. Its been slowly losing Rpms. It now only spins 5600rpms. I thought it was a Valve adjustment issue, nope I checked them like 3 times. I did a compression test, no issues, itÂ’s actually better then it was last year! (I think the good valve job helped) So I am starting to suspect The Springs are finally giving out! Somebody please give me your 2 cents!! Oh Ya the Cam is a Comp Cam 300AR with .663 lift and 254 dur @ .050, 110 lobe sep. The springs are also Comp Cams PRT# 938. 210lbs closed and 540lbs open pressure.

  2. #2
    BrendellaJet
    sounds like springs to me. They make kits you can test with. Not sure how accurate they are...but it will show how some springs compare to others.

  3. #3
    Beal Motorsports
    You should ask the comany that did the valve job. They should have checked the spring pressure at open and closed.

  4. #4
    FoMoCo
    I actually set up my own heads, I dont trust anybody. I just had them do a Valve Job and I installed the Valves and SPrings. I like knowing that I installed everyone with the correct installed height! I am going to buy a tester this week and pull one spring off to see what percent they are down. Thanks for the replys

  5. #5
    058
    I'd bet good money your springs are dead. Check your seat pressure as well as the open pressure. Low seat pressure will allow the valve to bounce on the seat killing hp.

  6. #6
    Brodie
    Originally posted by FoMoCo
    I actually set up my own heads, I dont trust anybody...
    I like knowing that I installed everyone with the correct installed height!
    Maybe you outta pay someone to do it right in the first place. Jest a thought.

  7. #7
    Challenged Pimp
    Now there's some useful input.....
    Those springs are 4 years old! I'm sure they've weakend over the years, I know first hand how much he likes to flat foot it.
    Replace them badboys, maybe change the cam while your at it.
    306/306 Dur
    270/270 Dur @.050
    .692/.692 lift
    108 lobe sep.
    :idea:

  8. #8
    Lookin for Liquid
    Originally posted by Challenged Pimp
    Now there's some useful input.....
    Those springs are 4 years old! I'm sure they've weakend over the years, I know first hand how much he likes to flat foot it.
    Replace them badboys, maybe change the cam while your at it.
    306/306 Dur
    270/270 Dur @.050
    .692/.692 lift
    108 lobe sep.
    :idea: And of course during the winter you pulled the rockers off to relieve the springs?

  9. #9
    Challenged Pimp
    Originally posted by Lookin for Liquid
    And of course during the winter you pulled the rockers off to relieve the springs?
    Umm I think I can speak for Phil when I say no. lol
    Another reason to change those suckers!

  10. #10
    Mike Schmidt
    If the springs are 4 years old, and your running a big roller, chances are they are dead. Additionaly, if they are 4 years old, its time for new anyways, are you willing to risk the rest of your motor on a 4 year old spring? $300 or ?????

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