I have had a couple engines fail in the past couple months. One is an STi, the other is an Evo 8 4g63. STi made it about 5k, Evo made it about 6K. Both engines have single rod bearing failure, both look to have misfired at TDC. Both have had the bearing flatten out ~2mm on the rod side. Both had the bearing on the rod cap stay together, and had minimal damage although they had ruined rod side bearings. Upon inspection of the rest of the engine bearings, the majority had very little damage unless caused by the material from the damaged bearing. None are flattened out like the failed units, nor do they show any odd wear that would suggest there was an issue with the cranks.

Now for the specs of the builds.
STi engine had .0023 clearance and ran 20w-50 oil. Brand new manley turbo tuff crank, OEM bearings, and brand new turbo tuff rods.

Evo 8 engine had .0024 clearance and ran 20W-50 oil. Used crank,but well within manufactures specs, ACL bearings, howard rods. Car typically idled at 20psi of oil pressure.

Both cars hit the dyno, the STi made 585 corrected whp, and the evo 8 made 670 corrected whp.

The STi failed a few days after the dyno session, as well as the Evo. Neither had any sign of weakness during the dyno tuning, and neither had any sign of detonation.

Now in the past 10 years I have built at least 60-70 4G63s. I have had zero fail due to abuse or normal wear and tear. The odd part of the two engines that failed is they had zero knock or engine noise prior to them failing. Typically an incorrectly put together engine will fail very quickly, not make good power on the dyno and show zero sign of premature wear. Oil changes were done at the first 50miles, then at 200 miles, then at 1000 miles. After that they were done at 2k mile intervals.

One odd thing I should note is the Evo catch can had 3-4 oz of e85 in the catch can, the valve cover has two -8 breathers on the valve cover and 6in x 3in catch can with 1.5in open filter. The can had been emptied about 3 days prior, and it was about 2/3 full of e85/condensation.

Any ideas? I'll post pics tomorrow of the damaged bearing out of the 4G63.

 

Coincedence?

 

That is what I was thinking, but I have another car in my shop that was tuned by the same person and it had a single rod bearing fail. This was a stock motor.

 

i hate to ask but is the tuner familiar with tuning on e85? i assuming all the failed engines were running e85.

 

All were tuned on E85. I need to get to my shop to take pics of the crank and bearing failure. The crank is stamped where the bearing smashed into it. The tuner has been tuning on e85 for a few years now, but I am thinking that the power level these cars are running are higher than what he is used to. I think he is cutting his tunes to close to the brink of destruction and it's killing them.

 

Pounding out bearings is too much timing or too much boost with too much timing. In the case of E85 where you dont see knock even past MBT it could be a combination of both. If I am gathering the info right, they were corrected numbers at altitude in Colorado?

If you can look at the maps on your own it would be easy to tell. The Evo shouldnt be over 19*, the STi in the mid 20s near redline at max boost.

Aaron

 

That's what I am going to be doing tomorrow Aaron. Would you be interested in taking a look at the AEM tune? It would be great to have a couple different people who really know their stuff let me know what they think. This is what I was telling my guys at the shop yesterday. I am fairly certain this is the last cars that will be hitting this dyno.

 

Yeah send them to the email in my sig and I will see whats going on with them for you.

Aaron

 

Also for those Coloradans wondering who tuned these, I will say it's no tuner in the denver or northern metro area.

 

Sounds like a bad tune done to both cars with the same mistakes.

 

Bro I feel srry for moh and abt aem tuners tobz performance tunes aem and my car is tune by him and is running like a chaamp bro and his personal car got an aem too

 

That really is not to good. Let me know what you find out Jon.

Sultan, I'm glad your car is running well, be careful out there.

Just for the record I did not tune these cars.

 

Tuner doesn't know how to tune Ethanol.

 

Right now it's just speculation, so we will see what we find on the tune tomorrow.

 

Itīs very easy to make mistakes on timing when burning ethanol. Iīd bet on too much timing. Too early high cyl pressure will cause that.

Itīs a widely avaliable fuel here in Brazil and the bad tuners love it because itīs almost knock free and gives a large safety margin of error.

In my Evo Iīm running the best gas we have here because ethanol will rust the fuel tank, clog injectors and pump if the car rest for a couple weeks and the mileage is a concern when we have just a tank of just 45 liters. If it was a purely road racing car Iīd run ethanol because it cool things down, but thatīs not the case.