Machine shops and overboring

Discussion in 'Modifications & DIY how-to' started by Cool_____, Jul 23, 2009.

  1. Cool_____

    Cool_____ Banned

    I'm getting my 2.5L overbored for 100mm pistons. Now my question is, should I make darn sure that a torque plate is used? Lots of arguements back and forth on other forums on this subject.

    Subaru doesn't call for one. Chevy and Fords do on their engine because the head bolts are right there next to the sleeves. However the open and semi-close deck Subies don't have any head bolts that are directly next to or affecting the cylinder sleeves. But some people swear that when they bolt up a torque plate and measure the cylinder bores are different sizes.

    So anyone here that has had a motor built successfully and ran for a while (LiquidForce?) can you confirm if your engine had a torque plate on it when it was bored over?

    FYI two of the biggest engine builders out there do not use torque plate and they themselves have said so. They are Ron @ Raw/Axis and Crawford. Now Crawford is a iffy subject with the bobble head pistons (mostly due to oversizing the bores too much for sustained track use) but again they are huge and been out there forever. Ron @ Raw/Axis is well respected and I know many people use them. There was a Raw motor at Topspeed last time I was there and it looked good but that's not saying much.

    Thanks.
     
  2. tolnep

    tolnep Member

    i'd like to know too.

    not knowing any better, i would want a torque plate used when the bores are sized and honed.. and do that put the block together when they do this too.. since this applies force..?

    and i would want the block assembled and torque plates used and the crank journals aligned bored too...

    go look at this video... he has others where he apparently doesnt use a torque plate...

    http://www.youtube.com/watch?v=SIgq2R_D5wU&feature=related
     
    Last edited: Jul 23, 2009
  3. Cool_____

    Cool_____ Banned

    I can't watch vids at work but seeing it's youtube would this video be John Edwards at Costa Mesa R&D in California?
     
  4. integroid

    integroid Supporting Member

    I can watch videos at work and your link does not work.
     
  5. Cool_____

    Cool_____ Banned

    Doh! Haha.
     
  6. nicad

    nicad Yes I am a troll

    torque plates are a must. and yes the bores will be slightly out of round, this has been proven
     
  7. Cool_____

    Cool_____ Banned

    Well I just got off the phone with Ron @ Raw and he disagrees.
     
  8. tolnep

    tolnep Member

    would be interesting to hear why some think its required and some not. If you check the video (costa mesa engineering . fixed url) you will see him prepare the sleeved block with a boring bar. if you check another video he does where he simply installs new forged pistons, he does not use a boring bar..
     
  9. Cool_____

    Cool_____ Banned

    Sleeves are a different ball game than a simple bore hone.

    The explaination is in my first post.
     
  10. nicad

    nicad Yes I am a troll

    how so? you're just pressing thicker sleeves in place of the factory ones, and then boring the sleeves. the same stresses still apply

    in any event, just have someone measure the cylinder without a torque plate, bolt one on, and re measure. it's not hard. no real discussion required

    I've done it, and there's a difference with respect to cylinder roundness. whether or not this translates into real world benefit is mostly speculation AFAIK
     
  11. Cool_____

    Cool_____ Banned

    Have you done it on a Subaru motor though?
     
  12. nicad

    nicad Yes I am a troll

  13. Cool_____

    Cool_____ Banned

    Thanks.

    Per Fuji themselves not needed. Bolt holes are outside and away from the sleeves which is why they designed the block that way. Only the closed deck engines need them.
     
  14. nicad

    nicad Yes I am a troll

    sounds like you already had your mind made up anyway. FHI also specifies procedures and values for OEM and stock vehicles. what's your point?
     
  15. slowwrx

    slowwrx Supporting Member

    I dont think its going to hurt anything if you dont have one that being said, I ordered one last week for David to use on my motors so he has one now...well he should have it shortly anyway
     
  16. Cool_____

    Cool_____ Banned

    My mind is never made up until I do it.....just ask Siegel :rofl:
     
  17. Cool_____

    Cool_____ Banned

    So all the other motors your Uncle built didn't use plates and they've been fine?
     
  18. slowwrx

    slowwrx Supporting Member

    Correct
     
  19. tolnep

    tolnep Member

    a guess. difficult to determine what the difference is except perhaps with the longevity of the rings and maybe how quickly they break in.

    what i find interesting is that you would torque with steel/iron inserts but not with standard bores.. i would assume the inserts would be less likely to oval than the bores themselves..
     
  20. nicad

    nicad Yes I am a troll

    the OEM lining is steel. realistically, you would do it with both. but anyone that is pressing in sleeves is usually going for big power, and that's why they do it. if you're not stressing the motor to the extreme, most people won't bother.
     
  21. Mike@TTR

    Mike@TTR Active Member

    Interesting discussion. I guess I would error on the side of safety. I am positive that it would not be detrimental to bore the motor with a torque plate. I know the machine shops that we deal with use them. When I get my block bored I will have them measure before and after if I remember. It will be several more weeks though.
     
  22. Cool_____

    Cool_____ Banned

    My local machine shop doesn't have the torque plate for the EJ. However I can get one for $300. I'm wondering if I should get one.....dang I hate decisions.
     
  23. nicad

    nicad Yes I am a troll


    it's a machine shop....why can't they, uh I dunno... make one?
     
  24. integroid

    integroid Supporting Member

    Thanks for making me spit Diet Mtn Dew on my screen, ASS!
     
  25. nicad

    nicad Yes I am a troll

    diet? :rofl: pussy.
     
  26. slowwrx

    slowwrx Supporting Member

    its cheaper and easier to buy one.

    I bought one for my uncles shop because that was the deal for him doing my motor, if your shop wont buy one what does that say
     
  27. Cool_____

    Cool_____ Banned

    They would make one but it costs at lot more than the $300 that I can buy one for.

    Matt the shop will buy one but they can't justify paying for it being that I'm the only freaking Subaru around here that will ever do machine work. I honestly can't blame them for that. However since I'll likely always run some form of built motor in my car I may just cough up the dough and buy one for myself :)

    Who you get your tq plate from? These guys? http://www.bhjinc.com/
     
  28. integroid

    integroid Supporting Member

    I am diabetic, ASS :)

    My new nickname for you will be ASS
     
  29. Cool_____

    Cool_____ Banned

    Lets stay on topic here......this isn't OT.
     
  30. nicad

    nicad Yes I am a troll

    why would it cost more to make one? they don't have to be fancy. maybe it's just the material cost and thickness, but hell I could see making one for under $300

    if it costs more to make one, how do the people selling them make money? MADNESS (refrain from lecturing me about economics and economies of scale)
     
  31. Cool_____

    Cool_____ Banned

    I think it's more of the fact they don't have raw aluminum that thick readily available.
     
  32. integroid

    integroid Supporting Member

    That would make sense. I am sure the company that makes the plates buy bulk raw aluminum vs a small amchine shop that owuld have to buy a little piece of aluminum. Kind of like how Walmart can buy things for about half of what a mom and pop store could buy the exact same item for.
     
  33. Cool_____

    Cool_____ Banned

    ^^^Exactly. Sounds like the general consensus though is that I would probably be better off getting a torque plate.
     
  34. nicad

    nicad Yes I am a troll

    a 1'x1'x2" 6061 aluminum plate is $150...
     
  35. Cool_____

    Cool_____ Banned

    Plus the machining the bolt holes and the two bores = another $150 prolly.
     
  36. nicad

    nicad Yes I am a troll

    I'll make my own and let you know how much it costs
     
  37. Cool_____

    Cool_____ Banned

    You have access to machining? How long before you attempt to do this?
     
  38. nicad

    nicad Yes I am a troll

    yes, and I dunno. probably when I find a box for your hitch
     
  39. Cool_____

    Cool_____ Banned

    Haha that'll be never.
     

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