Hey Guys i have just acquired a EVO8 with blown big end!! can anyone reccommend a stronger crank and rods to use in the EVO 8 motor???? cheers Birdy.

 

try:
http://www.roadraceengineering.com/

They sell race ready motors.

 

If the head block is salvagable, you might want to pick up one of the 2.3L stroker kits that are becoming available.

BTW, make sure you get all the crud out of everything, oil cooler, pipes, etc.. you want to be sure that everything is clean and tidy before you try to start up your fresh motor.

 

You might want to contact the shop about one of our new stroker kits that are becoming available.

 

Stroker needs to be very strong. Many with much experience building and blowing up strokers say go 2.2 no higher (or, more commonly, DON'T stroke the motor). When rpms get high with strokers, excentric forces become extreme and some feel you need a billet steel crank (~2 months and ~$2200+) to get relative reliability at high power outputs. In the 500-plus hp range, you can run stock bottom end...many are doing so and not breaking it. If you want to upgrade the pistons and rods, there are many who make aftermarket, many that are used, but concensus is that Crower rods or Pauter rods are among the best...Eagles not quite as strong. JE, Weisco, Ross all make good pistons...some feel Ross are best (DSM community with lots of experience here). The bottom end can be built to take 9000rpm routinely and be really solid...but not if you stroke it. If you stroke it, you might think about RnR, who build a longer block bottom with the 4G63 head. This reduces excentric forces slightly by lengthening rods (so they don't swing to as wide an angle) and gives you a full 2.4 L displacement. RnR states that their blocks can handle routine 8500 rpm (don't push them to 9000, but if they go there from time to time briefly, they'll not likely have any problems).

Overall, if you're just rebuilding with a stronger bottom end, you can use stronger rods and pistons...but if you blew up your bottom end, it's likely not because of weakness of the rods or wrist pins or crank or pistons, but rather due to pre-ignition. Unless you were running sick amounts of power. Tuned properly, the stock 4G63 bottom end is putting up over 500 whp reliably.

I'm still trying to learn about all of this, but that's a brief synopsis of what I've gleaned.