1. This site uses cookies. By continuing to use this site, you are agreeing to our use of cookies. Learn More.

SV650 Carillo H beams. A bit longer than oem rods?

Discussion in 'Tech' started by regularguy, Mar 4, 2013.

  1. regularguy

    regularguy Always Krispy

    Anyone get tight squish numbers using Carillo H-beams in a SV650? I'm using oem gaskets and the cylinders have not been decked. Using rosin filled solder to measure squish and numbers are tight! Pistons are from a busa.
     
  2. ed who?

    ed who? the opposite of eharmony.

    not that i have seen, but i dont use busa pistons. They should be 4.744" iirc
     
  3. regularguy

    regularguy Always Krispy

    They are. I'm using busa pistons in Gladius (nikasil) cylinders. The cylinders haven't been decked and with oem base gaskets I'm right on the edge of no mans land.
     
  4. ed who?

    ed who? the opposite of eharmony.

    one guys no mans land is another's comfort zone... the key is to know the difference. :) squish varies a lot depending on type of rod your using let alone piston designs.. just saying. If your not comfortable, change it by getting custom base gaskets or decking pistons a few thd's. You wont notice .002" in hp but you will upon contact..
     
  5. regularguy

    regularguy Always Krispy

    Already have base gaskets enroute to get it where I feel comfy. The SV flexy crank needs a bit of room to dance...
     
  6. Mr Sunshine

    Mr Sunshine Banned

    The rods aren't longer. The Busa piston's wrist pin location is lower. This is one reason why the compression is higher with those.

    Why are you using Busa pistons anyhow? There are better stock bore pistons for racing.

    Are you using the Busa rings too due to the nikasil cylinders?
     
  7. regularguy

    regularguy Always Krispy

    Negative. Distance from wrist pin to top of pistons are the same.

    Why busa pistons? They retail for 100 bucks each brand new, they weigh about 306 grams with all the goodies attached, and they're strong enough to survive in a street busa with 220hp at 5psi of boost. A set of custom pistons that weigh about the same as stock SV pistons (317 grams) run about $520

    I might be limited on compression due to PTV issues with the big cams I'm using but they're other ways to deal with that. Right now with the squish I'm using and .030 off the heads I calculated 12.6:1 comp ratio. I'd like to get to 13:1

    Yes, I'm using busa rings to comply with the nikasil bore on the Gladius jugs.
     
    Last edited: Mar 6, 2013
  8. BrianC636

    BrianC636 Well-Known Member

    So if your heads have .030 off of them, what about .040? The reason I ask, I was given a set of heads that have what we think is .040 off of them and I'm wondering if I should keep them or just pitch them.
     
  9. Tdub

    Tdub Say what???

    What is your reasoning with the different rings??
     
  10. BrianC636

    BrianC636 Well-Known Member

    If he's using Gladius cylinders he will have to use the Busa rings since both (busa and Gladius) are nickasil coated. At least that's my understanding.
     
  11. Tdub

    Tdub Say what???

    And what is special about the 'busa rings???
     
  12. ed who?

    ed who? the opposite of eharmony.

    I'm sorry did you say 30 thou off heads???? Wow.

    Also Busa pistons are great piston I just don't use as in prod builds we can't and in SBK most guys want custom.
     
  13. regularguy

    regularguy Always Krispy

    .030 is not a lot on SV. There's a ton of room in there.
     
  14. ed who?

    ed who? the opposite of eharmony.

    Oh I know you can take 30 off. Done a ton of SV. Just never had to take that much off.

    No worries. Good luck
     
  15. regularguy

    regularguy Always Krispy

    Yes they're junk. Send them to me.....:)

    You can use them but you're gonna have to do some measuring. Most likely, cam timing will have to be changed to get correct PTV.
     
  16. regularguy

    regularguy Always Krispy

    Pistons are dished so I'm chopping to get compression. I guess it's left over from the good old days of WERA LW Superstock suzuki cup money, it was not uncommon for racers to chop 050 and even 060 off the heads, degree the cams, and let em rip.
     
  17. regularguy

    regularguy Always Krispy

    The busa pistons are a bit bigger even though they both say 81mm. The busa slugs can fit tighter (Nikasil) so the slightly larger busa rings close up the ring end gap. The SV rings will work but end gap is kind of out there. Plus there's an arguement that busa rings are suited for nikasil and sv rings are not beacuse they are made for iron bores. Not sure about that though..
     
  18. RM Racing

    RM Racing Tool user

    True. And if you use Busa rings the end gap may be too small, which is worse than too big, but fixable.

    And, per your comment in an earlier post, 0.060" off an SV head will lose power over a properly set up engine with half that. Taking that much off the heads is a bit hackish.
     
  19. BrianC636

    BrianC636 Well-Known Member

    Sent you a request on the facetubes...

    Seriously though, if you end up needing them hit me up.

    It's going to be a while before I tear into my 2nd gen motor so if you need them we can work something out.

    They are 1st gen heads.
     
  20. Mr Sunshine

    Mr Sunshine Banned

    I think you need to check your measurements.

    And as to custom pistons...$360 for the set...lighter than stock SV pistons (but heavier than 2mm over pistons). Want me to show you a picture?

    You want 13:1 comp...that's pretty low? I usually run 14.2ish.

    Also you said you took .030 off...what did you end up with on your head volume? That's the real number to care about.
     
    Last edited: Mar 6, 2013

Share This Page