Quote:
Originally Posted by Homemade WRX
you do know that the K20 is an 86mm stroke and 86mm bore as well, right?
I have a few things up my sleeve for the FA engine based off of what I already know for the FB25 and handed down from extensive EJ building and K-series work.
put simply, I'm not scared  |
Yeah, but it has 139mm connecting rods (from google) rather than 133 (what I calculated for the FA20, using the "same dimensions as FB20" + increased compression ratio), giving a rod:stroke ratio of 1.616 instead of 1.547. The redline is approprately, a bit higher. I just don't see how 9000rpm could work safely on a comparatively long stroke and short rod when everything else that runs >8000rpm has much longer rods and mostly shorter strokes. Even if some quick calculations give that the overall bearing load is only 0.5% less and sideloading is only 5% less, I can't help but think there's a good reason high rpm engines go for >1.6 ratio.
But I'm curious to hear what you have in mind.