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CTR pistons on LS rods?

Discussion in 'Engine Building' started by jake2001z001, Nov 12, 2003.

  1. jake2001z001

    jake2001z001 Senior Member

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    hey everyone, im gonna be build up a ls vtec, now i was wondering, will the ctr pistons fit on the ls rods or will i have to have some work done, and are the ls rods to week, im gonna be going all motor, do they make rods that fit a b18 bottom but will work for ctr or itr pistons? anyone have any idea
     
  2. MaaseyRacer

    MaaseyRacer Senior Member

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    well b16 pistons fit on LS rods, and CTR pistons fit on b16 rods, so i am going to say that CR pistons will fit on LS rods, and you will probably yeild about 12:1 compression...
     
  3. jake2001z001

    jake2001z001 Senior Member

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    is that hi enough for a ls vtec, i want a monster, and what kinda rods whould be good to upgrade too, that will fit ctr pistons and the b18 bottom
     
  4. saturn_boy96

    saturn_boy96 88 C1V1C 53D4N DR1V3R

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    hey man, i'm selling a brand new set of CTR pistons, but in order for the pistons to fit the stock ls rods you have to have some machine work done. i think the rods have to be shaved slightly to fit the CTR pistons, but i know that they wont "bolt-up".

    let me know if you want them.
     
  5. brettII

    brettII KMS-fab

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    crower rods are always good....carillo, good, pauter-i've heard some things. pretty penie for some of them but hey you get what you put in

    brett
     
  6. no2psi

    no2psi Senior Member

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    I am using CTR and LS rods. You need to have the small end milled to fit in the piston. I would have as little as removed as possible. Because this weakens the rods. My machine shop did this for 40 dollars and that included pressing the pistons. good luck.
     
  7. gocivicls

    gocivicls Senior Member

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    B16A pistons will fit B18B rods and B18A rods.
    B16B or (CTR) pistons will fit B18A rods, but not B18B rods (1994 or higher LS) without getting them modified.

    I just did them same thing, and got my rods shotpeened and resized with ARP rod bolts. I only spent $169-pistons, $150-rods shotpeened, resized. & $80-pistons shaved to fit my rods. NOT BAD.
     
  8. gocivicls

    gocivicls Senior Member

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    Get the piston modified and not the rod to ensure strength. Shaving the rod will not be good for all motor-high rpm application.
     
  9. timEspeed

    timEspeed Senior Member

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    how do CTR pirstons fit LS rods when the bore is different b/w a b16 and a b18? Or is it just that the b18 has a taller cylinder to get the extra .2L diplacement?
    ~timE
     
  10. gocivicls

    gocivicls Senior Member

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    The bore is the same for the two. The difference in displacement is from the stroke.
     
  11. timEspeed

    timEspeed Senior Member

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    ok, I thought that might be the case
     
  12. timEspeed

    timEspeed Senior Member

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    so then, what are the bore diameters for all the different b motors?
     
  13. phunky.buddha

    phunky.buddha Admin with a big stick Admin VIP

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    B16A/B, B18A/B/C = 81mm bore
    B20B/Z = 84mm bore
     
  14. timEspeed

    timEspeed Senior Member

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    Good deal. Now if the b18 has the same bore but a longer stroke than the b16 whats that mean in terms of R/S ratio, piston speed, and pressure on the cylinder walls? I would think that because the b16 has a higher rev range the internal geometry would make it a better canidate for FI set ups. If this is the case, then why do people run LS/T more than b16 turbo?
    ~timE
     
  15. timEspeed

    timEspeed Senior Member

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    I didn't mean to jack the thread, I'm just curious. I think Internal Geometry is one of Honda's high points and it seems to be overlooked alot. Any1 know what I'm talkin about or what?
     
  16. phunky.buddha

    phunky.buddha Admin with a big stick Admin VIP

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    Lots of domestic engines are actually built very close to that "ideal" rod stroke ratio... more so than our beloved B18s. Internal geometry does matter, but Honda has been able to make a low r/s ratio work out just fine.

    As for your previous question- yes the B18 has a longer stroke than the B16, and yes more people run boost on it. The geometry of the engine is not too crucial at the power levels that most people are running at... but it does play a role in how the engine behaves. You have higher piston speeds and less dwell at TDC and BDC. Higher piston speeds promote more rapid intake and exhaust events- you breathe more over the same time period. You also get more torque. More displacement and more torque is why you see a lot of people running B18 turbo over B16 turbo. Cost is another factor. You can nail 250whp pretty easily on a B18 turbo without any internal modifications and without VTEC- and you'll still have more torque than the B16 that was only able to make 250whp on boost too.

    So...

    B16 R/S = 1.745
    B18A/B R/S = 1.541 (pretty sure)

    You have more side loading and stress on the B18, but most people don't really have problems with it- and it's just plain cheaper than the B16.
     
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