All photos are available in Quick update on the Evo engine rebuild...
This is the block after 90,000 miles:
It's in the machine shop now getting built/balanced with new aftermarket pistons, (.020 over) rods, and stroker crank. (2.0L to 2.4L) Also larger valves (+1mm) new dual-spring valve springs for the already oversize cams (272 intake, 264 exhaust) new clutch, lightweight flywheel, and balance shaft removal kit. It was already making about 350hp at the wheels with stock block/turbo/intercooler, so we're expecting about 500awhp once we upgrade the turbo and intercooler later on this year with this larger block. Stay tuned!
15 comments:
" Stay Tuned " I get it !
90k and the original crosshatch is darned near flawless. Gotta love modern manufacturing.
Imagine how good it'd look if it had oil in it.
Oils for city folk !
Expected 500 awhp in that little car...Wow! U B careful in that little demon!
Why remove the balance shafts? They don't seem like an awful lot of power loss compared to their vibration damping.
RC51: I honestly hadn't even thought of it that way. Good catch!
Flash: Ouch.
Dad: Definitely. Probably just keep the boost turned down when playing on the twisties, and only turn it up if I go drag racing.
Motor: With the rotating assembly properly balanced/blueprinted, there should be no need for the balancing shaft. It not only frees up horsepower, it also reduces the chance of a belt failures ending up in catastrophic damage to the motor.
Have a feeling that the rotating assy in the car is probably pretty well balenced already...even for a production car. Balance shafts are usually included for non-primary harmonics. You may find a buzzy rpm without them.
Full-Race Twinscroll GT35R?
LongFellow: That's an option I have looked at...also considering the 3076 kit for quicker boost, but leaning toward the 35R.
rdhunt: Exactly. The balance shafts don't have anything to do with the engine's balance or rotating assembly, they counteract the engine's secondary imbalance (which doesn't go away, ever). http://en.wikipedia.org/wiki/Straight-4 "balance and smoothness."
Hmm...interesting read, thanks guys. May reconsider the balance shaft removal...will do a little more research among those who've done it.
maybe when your all finished you can start practicing the gymkhana
KB,
The other thing you may want to think about with the balance shaft removal is the effect on the gear box. We've had some terrible issues with premature gearbox wear/failure with i4 motors and no balance shafts. The inherent vibration of an i4 motor is quick severe without the balance shafts. I'd keep 'em if I were you...What are you going to do about engine management? Let me know if you'd like a deal on a MoTeC PnP ECU...
mwelch: I wish! Need a lot more flat space than we have around here. ;)
$1_Colin: Right now I have TurboXS UTEC piggy-back engine management. It's supposed to be awesome for a non-standalone, but I've never learned to program it and I'm about to get a crash course in it I'm guessing.
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