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  1. #1

    WSM 4-tec pistons. Cast or forged? Opinions?

    I have one week to have this engine built and running.
    WSM is 20 minutes from me (fastest resolution).
    Has anyone had first hand experience with their pistons?
    Are they cast or forged?
    How about their valves and timing chain?

  2. #2
    Primary Language: Sarcasm Pony Racer's Avatar
    Join Date
    Jun 2011
    RiverShit, Ct
    pm slow91..

    I was just at his shop last week and held one of their pistons.. they are light and very strong.. I think he is running them in one of his skis..

  3. #3
    The pistons they are forged (you have to modify the piston squirters), I have not used their chains so I can't comment, a friend used their valves years ago without issue, but i would go with Supertech or Ferria

  4. #4
    Its a stock build as of now. Yes I read about the piston squirter issue. I just texted beerdart and he says the WSM pistons look really nice.
    I have seen them myself and agree. Its hard to see the metallurgy though.
    The engine is one of two that are in my 200 speedster 430hp. I plan to do the et127/42lb/external intercooler/4" intake upgrade once the boat has some runtime.
    In my experience with WSM they have taken great leaps in quality these past few years.
    I even used the first 4-tec crankshaft they made (right off the pallet from China). Its looked better made than the sheered oem crank it replaced. The casting was flawless and the journals looked chromelike.
    The timing chain concerns me though. Lots of bad things can happen if its not a winner. Waiting for a 2008 and up OEM one will threaten my deadline.
    machine shop will be boring the case tomorrow. It doesn't have any damage. Just a slight shadow of a ridgeline on cylinder tops but figure its worth the $150 since im replacing pistons anyway.
    Any reliability issues with an oversize bore? Thanks for the fast responses. Im trying to make all parts decisions tonight.

  5. #5
    Do the case main bolts need replacing or are they reusable? Talking about the 8 bolts under the aluminum caps

  6. #6
    I just completed a FRESH Bore on a 2006 RXT 215 With WISCO forged pistons. Engine runs Perfect. set the piston skirt clearence up at .003

  7. #7
    did the rod castings hit the piston crown when angled towards the skirt?

    Quote Originally Posted by joe w View Post
    I just completed a FRESH Bore on a 2006 RXT 215 With WISCO forged pistons. Engine runs Perfect. set the piston skirt clearence up at .003

  8. #8
    Thanks Joe, but im not using Wiseco pistons.
    Gunna have to make parts choices within the next few hours. Could use some help right away.
    Question 1 Can I reuse the 8 case/main bolts again?
    Question 2 Is it considered unsafe to overbore the case to the next size over stock?
    Question 3 Is it ok to use a 2004 628 camshaft in place of the 2007 851 cam?
    Question 4 Are the oem 2007 flywheel and cam gear bolts good for reuse?

  9. #9
    ou812's Avatar
    Join Date
    Jun 2006
    #1 yes, they are reusable
    2 no
    3 yes, recommended..
    4 no and yes... NO, get arp flywheel bolts or new oem bolts, YES you can reuse the sproket bolts a few times before i'd ditch them. Use red loctite on them

  10. #10
    Exactly what I was hoping to hear. Thanks man!

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