Engine teardown after 3 years of track/race use

[Bimmubishi]

I expected much worse. After the thread about the short balance shaft snub failing due to lack of support from the shortened balance shaft, I got worried. After three years of use I thought that I'd be cautious and tear the motor down, expecting to have to do at least the bearings, rings and a re-hone.

I used heavy Mobil 1 oil the whole time.

Here are some pics-

Oil Pump Shafts- zero scoring.

Rod bearings- no flattening but a little wear, no gouges or scratches at all but some shiny spots here and there..

Main bearings- look very good as well. Very clean, no gouges or scoring.

Oil pump face-

A little scoring here. It's going to be replaced. Engine front cover has zero scoring. I'll reuse that.

Piston skirts look great, no scuffing. No signs of detonation on the top.

I'm going to send everything to the machine shop and have them magniflux the crank, rehone, measure the big rod ends and magniflux the rods. I'm very happy with the way it's held up. Maybe I got lucky.

 

[ktmrider]

Nice, I would say not so much luck but attention to detail.
No knock on anyone who has had failures but not shortcutting on quality and paying attention to the little things ends up with results like yours.

 

how many hard miles would est. you put on the motor in those 3 years???

 

[Terry Posten]

Please take a minute to look at the TB. Make sure the blade screws are still tight. /ubbthreads/images/graemlins/crazy.gif

 

[Bimmubishi]

Terry, thanks. I just rebuild another one for next year. I checked after I saw your post. That made me /ubbthreads/images/graemlins/frown.gif

 

[Bimmubishi]

Kryger, good question. I think I've probably done 20 track days and 6 or 7 hillclimbs. I think also about 15k street miles before I took the car off the road for good and began towing it. I had three different turbos and two different engine management systems on it. It started for a season at about 220whp with the standard Evo parts on it, then the next year 325, then retuned to 365 and this season at 490 with a bigger turbo. It's seen a lot of time at redline and visited the rev limiter at 7800 at least 20 times.

I would say a good track day would put at least 200 miles on the car at full bore.

 

[Brianawd]

Looks good. Good oil is the key. I know when I pull my motor apart after it over heated bad the bearing,crank,head,cams and oil pump all look perfect. The only part of the motor that showed that it over heated was the pistons and cylinder walls. But even then my machinist said the block was not that bad and the pistons cleaned right up and are going into a friends motor.


Royal Purple FTW

 

so it is safe to say ~20-25k, 5-10k were abused like a red-headed step child?

 

[Bimmubishi]

Yeah probably closer to 20k. I'm having a hard time putting an exact number together since I didn't record mileage. I've doubled the mileage on the car since I've owned it but not all on one motor- the first year I had the stock 7 bolt.

 

[s_firestone]

Quoting Brianawd:
Looks good. Good oil is the key.



+1 on good oil. I use Mobil 1 and I'm in the middle of changing the timing belt/water pump at 170,000 miles. I blew the turbo coolant hose and although it caused no damage, the water pump diaphragm began leaking soon after. while I'm doing a lot of cleaning, I took off the valve cover and everything looks better than it did when I replaced the old head 5 years ago. The old head on dino oil was golden brown, and this head is clean as a whistle and the aluminum as white as a new rebuild.

Now if I could just figure out a way to keep the oil inside the engine rather than lubricating the outside... /ubbthreads/images/graemlins/uhh.gif

 

[PreskitVR4]

very nice. My teardown very similar, same thing, 15-50 Mobil 1. Just over 100K on a low milage JDM, ridiculous amounts of track time, daily studderboxing, even blew an oil preassure sending unit at the top end of the track once without a drop of oil left in it. I credit this luck to Mobil 1.