PanzerAce Posted February 2, 2009 Share Posted February 2, 2009 I created this thread because there is already a fair bit of basic knowledge about which engine blocks to use for strokers, which crank to use (LD28), heads are decently well known, but I haven't seen any thread devoted to the discussion of con rods. So here are my questions: 1a) When building a stroker motor, which 'standard' (ie, L series originally) length conrod is the "best" one to use? L24? L28? One of the four cylinders? 1b) Or is there a non L series rod that people prefer? 2) What are people referring to when they talk about 8mm or 9mm L24 rods, and why does everyone want the 9mm ones? So some of the above are probably noob questions, but it's come up recently for me and I'd like to know. Thanks guys. Quote Link to comment Share on other sites More sharing options...
Challenger Posted February 2, 2009 Share Posted February 2, 2009 The 8mm and 9mm refer to the bolt size. http://forums.hybridz.org/showthread.php?t=134861&highlight=8mm+9mm+rods Quote Link to comment Share on other sites More sharing options...
naviathan Posted February 2, 2009 Share Posted February 2, 2009 Most common that I know of are the 9mm L24 rods. In combination with the KA24 pistons and LD28 crank you get a 3.0/3.1L L6. 8mm and 9mm refer to the bolt thickness. Quote Link to comment Share on other sites More sharing options...
zcarnut Posted February 2, 2009 Share Posted February 2, 2009 So here are my questions:1a) When building a stroker motor, which 'standard' (ie, L series originally) length conrod is the "best" one to use? L24? L28? One of the four cylinders? 1b) Or is there a non L series rod that people prefer? 2) What are people referring to when they talk about 8mm or 9mm L24 rods, and why does everyone want the 9mm ones? These questions are covered in the “3.0 and 3.1 liter FAQ “ I wrote years ago: http://www2.zhome.com:81/rnt/L28conversion/3031FAQ.html Quote Link to comment Share on other sites More sharing options...
ezzzzzzz Posted February 3, 2009 Share Posted February 3, 2009 I'm using L20B rods (145.9mm long) and custom JE pistons. Oh, I'm also using the LD28 block and crank. 1.75 rod/stroke ratio and 1.02 stroke/bore ratio. The displacement is still roughly 2.8. Quote Link to comment Share on other sites More sharing options...
PanzerAce Posted February 3, 2009 Author Share Posted February 3, 2009 I'm using L20B rods (145.9mm long) and custom JE pistons. Oh, I'm also using the LD28 block and crank. 1.75 rod/stroke ratio and 1.02 stroke/bore ratio. The displacement is still roughly 2.8. That actually raises another thing I was wondering about: what is the big deal with rod/stroke ratios? Quote Link to comment Share on other sites More sharing options...
Noddle Posted February 3, 2009 Share Posted February 3, 2009 That actually raises another thing I was wondering about: what is the big deal with rod/stroke ratios? I had always thought it was to do with RPM verses Torque from my motor bike days, shorter rod / higher RMP, longer rod / slower RMP but more torque. I'm sure if I'm wrong some will say so. Nigel Quote Link to comment Share on other sites More sharing options...
ezzzzzzz Posted February 3, 2009 Share Posted February 3, 2009 In it's simpliest form Nigel has it correct. Instead of going into a long disertation here I'd suggest googling rod/bore ratio and bore/stroke ratio. Quote Link to comment Share on other sites More sharing options...
PanzerAce Posted February 3, 2009 Author Share Posted February 3, 2009 bore/stroke ratio I have a decent enough grasp on already I think (plus, with a Z unless you sleeved your cylinder bores, you couldn't even get to 1:1 anyways). Guess I'll read up on rod/stroke in lecture today if it's stuff that I've already learned Quote Link to comment Share on other sites More sharing options...
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