Long-rod BP build underway
#23
JKav (Jason Kavanaugh) works for Inside Line (Edmunds) and he's not selling anything. I'm sure all the gory details for the build will be included in the continuing "1997 Mazda MX-5 Miata: Long Term Road Tests" series found here. You can read about the details as soon as they publish them, just like everyone else. As to the benefits, look at the link hussy posted or read the damn article linked w/comments and it should be somewhat obvious.
Ungh, why do I bother?
Ungh, why do I bother?
#26
BP rod length and piston height
5.228 + 1.20 =6.428
Honda rod and custom piston length
5.392 + 1.020 = 6.414 (.014 diff) Rod ratio increases to 1.611
The BMW rod is 5.510.
This means that the piston height must be .919 (23.342mm)to make the stock height of 6.428. Rod ratio works out to 1.64. I didn't think J&E or Wisco could do that short.
JKav, what did you say the piston height was for these?
5.228 + 1.20 =6.428
Honda rod and custom piston length
5.392 + 1.020 = 6.414 (.014 diff) Rod ratio increases to 1.611
The BMW rod is 5.510.
This means that the piston height must be .919 (23.342mm)to make the stock height of 6.428. Rod ratio works out to 1.64. I didn't think J&E or Wisco could do that short.
JKav, what did you say the piston height was for these?
Last edited by 2manyhobyz; 02-25-2012 at 09:37 PM. Reason: typo
#34
I spent many an hour pouring over con-rod specs to try to find an off the shelf rod for a long rod for my non-vtec b18 motor. MotoIQ is building a long rod vtec B18 motor using Nissan rods but suprisingly the non-vtec and vtec crankshafts are quite different, so the Nissan rods won't fit my crank (non-vtec rod journals are wider).
My question was always this: What change in rod/ratio makes this all worthwhile?
Of the long rod builds I've heard about, everyone seems to be getting around a 0.08 increase in rod ratio. That's about what motoiq got with their SR20 motor and it seemed to have an appreciable affect.
To get a +0.08 rod/ratio for my non-vtec B18 it looked like I was going to have to get cutom pistons and rods, the dollars and cents just wasn't adding up for me.
My question was always this: What change in rod/ratio makes this all worthwhile?
Of the long rod builds I've heard about, everyone seems to be getting around a 0.08 increase in rod ratio. That's about what motoiq got with their SR20 motor and it seemed to have an appreciable affect.
To get a +0.08 rod/ratio for my non-vtec B18 it looked like I was going to have to get cutom pistons and rods, the dollars and cents just wasn't adding up for me.
#38
More geeky deets, this time on the JE pistons. FSR, yo.
http://blogs.insideline.com/roadtest...the-house.html
#39
Pssht, I'd be in. Hey Sav, wanna put a set in my motor?
Such a tease...
More geeky deets, this time on the JE pistons. FSR, yo.
http://blogs.insideline.com/roadtest...the-house.html
http://blogs.insideline.com/roadtest...the-house.html
#40
Question on the 2618 alloy. Since it has a higher rate of thermal expansion, and thus requires larger clearances, doesn't this mean that on a "daily" engine, were the engine spends a significant amount of time in cold condition, the cylinder walls will wear down a lot quicker, promoting an oval-like shape and losing compression in no time at all?
This seems like an alloy ideal for racing applications, where you don't actually expect an engine to last more than 10,000-20,000 racing miles.
This seems like an alloy ideal for racing applications, where you don't actually expect an engine to last more than 10,000-20,000 racing miles.