turbotaloon95

iTrader: (7)

Hello fellow evo-ers. Long story short, my motor is out of the car because the transmission is getting rebuilt and I needed to replace the wiring harness. The motor is a stock evo 9 block with roughly 50k on it, the cylinder head is a stock evo 8 head that I had rebuilt (all oem parts) last year. The motor is on the stand, head is pulled as I will put all new timing components and head gasket on. My original plan to "freshen" up this motor was to pull the pistons, hone the cylinders, replace the rings, and replace the bearings. I've had mixed opinions and not sure if I should even bother or not. I don't plan to upgrade the rotating assembly or get any machine work done. The motor ran fine before it was pulled, I just want to help increase longevity at this point. The "build" will be mild and HP expectation is somewhere around 400hp. What do you guys think?

2006EvoIXer

iTrader: (1)

Pictures of your cylinder walls? Are cross hatches all there? I would look inside oil pan while engine is out and verify nothing is in there. Doesn't hurt to push on rod to make sure there is no play on any connection to crank.

barneyb

Rings, pistons and cylinder walls all wear - its a system. So, when wear reaches the point where sealing is a problem all three must be brought back to spec. In fresh engines people have done drop in piston replacement. My opinion is that 50K is getting into the mileage range where this is no longer suitable.

Bearings can run 3 - 400,000 miles if the engine is taken care of or be destroyed driving around the block if the engine is run out of oil. Once a bearing fails and its metal travels throughout the oiling system its basically overhaul time if your goal is a permanent fix.

I'd suggest the best thing to do to maintain the engine is looking after fuel. Injectors don't last forever and need flow testing and maybe replacement after long service.

If you are into racing and competitive events, the engine should be looked on as a consumable just like tires or brakes and torn down, inspected and rebuilt at the end of each season or at whatever interval your use dictates.

GSX_TO_EVO

iTrader: (5)