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Bearing Damage

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llxkevinxll

10+ Year Contributor
532
269
Jan 29, 2012
Milwaukee, Wisconsin
Current setup:
-6 Bolt 2.0L
-Eagle Forged Crank
-Manley 9:1 pistons, coated (effective 10:1 with machined head)
-Factory rods, shot peened
-King XP Bearings
-1mm oversize, coated and swirled, stainless SI valves
-Factory turbo cams
-ARP rod and main bolts
-Rewired walbro 255
-NGK BPR9ES Plugs
-FIC 750cc injectors
-TD06SL2 20G
(check car profile for further details, pertinent information above)

This vehicle is/will be used for autocross and road racing primarily, occasional drag passes, and is street driven. My goal is 375 awhp.

The main issue is that the motor suffered bearing failure and the cause, we believe, was the small 16g on a higher compression motor with factory 2g timing. We checked the plugs constantly before pulling the motor and never saw any of the normal signs of abuse. I have attached pictures of the #2 rod bearing halves to this post. The other cylinders looked similar but less sever. They did not spin but the motor had a terrible rattle for 2 years when at part throttle which finally prompted us to pull the pan. My theory is the damage was done with the poor tune and small turbo building boost too quickly (into positive boost while resting your foot against the pedal in the higher gears) and then continued to wear from that point.

The motor compression tested at 210-220 psi per cylinder before being recently rebuilt. I had been running ~15-16 psi on the 20g and had been making at or near my power goal.

So given all of the data above, does anyone feel E85 is required to safely and reliably make 375 awhp on this setup? Did undetected detonation running 93 cause the cylinder pressures to spike so high the bearings were beat up?

thanks for taking the time,
Kevin
 

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the 16g did not cause those bearing failures. were those oem bearings? what oil were you running?

also, the tdo6sl2 turbo will likely need 27-28 lbs to reach your power goal. You may not make it that far with higher compression on pump gas. I ran a forced performance td06sl2 for almost a year at 30spi before it blew up and I found they had high failure rates. Mine was accelerated due to the fact that i was spinning it beyond it's peak operational range. I needed methanol for that psi range, made about 400 on an all stock motor.
 
the 16g did not cause those bearing failures. were those oem bearings? what oil were you running?

also, the tdo6sl2 turbo will likely need 27-28 lbs to reach your power goal. You may not make it that far with higher compression on pump gas. I ran a forced performance td06sl2 for almost a year at 30spi before it blew up and I found they had high failure rates. Mine was accelerated due to the fact that i was spinning it beyond it's peak operational range. I needed methanol for that psi range, made about 400 on an all stock motor.

Those were ACL Race bearings. I have been running Rotella since the motor was built. Initially their conventional and then moved to the T6 synthetic when they changed the zinc content in the conventional. The builder has adjusted the oil clearances since taking it apart so maybe it was an oiling issue?

On the freeway, 16 psi, I was able to stay next to a car with a known rwhp of 360ish so I think I am close to the goal with the tune I had. But I agree, the boost level and apparent power don't seem to line up. Boost was verified with both a GM MAP through ECMlink and a mechanical autometer gauge.
 
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What do you mean "adjusted bearing clearance".
How, what was adjusted to, did he adjust all of them.
You need to take crank measurements before replacing bearings.
Mandy
 
were the bearings coated?
what clearances were you running and what was the weight of oil?
 
Those were ACL Race bearings. I have been running Rotella since the motor was built. Initially their conventional and then moved to the T6 synthetic when they changed the zinc content in the conventional. The builder has adjusted the oil clearances since taking it apart so maybe it was an oiling issue?

On the freeway, 16 psi, I was able to stay next to a car with a known rwhp of 360ish so I think I am close to the goal with the tune I had. But I agree, the boost level and apparent power don't seem to line up. Boost was verified with both a GM MAP through ECMlink and a mechanical autometer gauge.
This is bench racing at its finest. Get objective measurements.
 
Get objective measurements.
What he said ^^^^^^^^^^^^

Your engine builder should be giving you your engine specs. If he's not, you might wanna find a new builder. Any place that knows their sh1t will give you something like:
You must be logged in to view this image or video.
 
Kevin
You knew 2 yrs prior to pulling the pan you had a problem, but instead you went and tried to stay with a car with 360 rwhp, you seem more worried about your HP numbers than the health of your motor.
Nowdays, someone puts an engine together and that makes him an engine builder there are mechanics putting engines together which are very good, dont misunderstand me, but they are not engine builders as such.
I t looks like your high comp and 93 gas at that boost induced detonation, do you know how much timing you had and at what rpm.
There are a number of things or combinations that could have made your bearing to walk like that.
.
 
Yes, this is not a detonation issue, it is either oil starvation, rod bolt issues, machining/clearance issues or dirt in the oil hiding in that journal (unlikely).
 
were the bearings coated?
what clearances were you running and what was the weight of oil?
Oil was Rotella T6 5w-40.
Clearances I am unsure on. I will ask for the measurements (assuming he still has them).
They would have been out of the box ACL Race bearings. He never mentioned coating of any kind on the bearings. Only that the pistons were coated.

This is bench racing at its finest. Get objective measurements.
Kevin
You knew 2 yrs prior to pulling the pan you had a problem, but instead you went and tried to stay with a car with 360 rwhp, you seem more worried about your HP numbers than the health of your motor.
Nowdays, someone puts an engine together and that makes him an engine builder there are mechanics putting engines together which are very good, dont misunderstand me, but they are not engine builders as such.
I t looks like your high comp and 93 gas at that boost induced detonation, do you know how much timing you had and at what rpm.
There are a number of things or combinations that could have made your bearing to walk like that.
.
I am uninterested in power figures. The first reply said 27-28 psi needed on the 20g for my horsepower goals which would be difficult on pump 93 and a 10:1 motor. To word my initial response more clearly, the car made plenty enough power for me at 16psi on the 20g. Whatever that number may be. I am not claiming to have some specific horsepower, only that the power it was making at 16psi was enough.

You are correct, the noise existed for some time, two years or about 300 miles (or less) and during that time every effort was made to find the source of the noise. We did not see metal in the oil while draining and checked everything else in the top end for the noise. we had a stethoscope on the car more times than I can count trying to pin point it. The car was running and driving the day we pulled the pan and found the bearing damage. We had made the assumption that a bearing issue would have gotten more severe far faster than it did. The noise did not change in intensity and the rpm range that created it did not expand the entire time the car was driven. Should we have dropped the pan sooner? I guess so.

As for timing, looking now it was a bit high in the lower rpms, 15* at 3000 rpm with a low point of 8* around 5000, climbing back to 16* at 7200 rpm. Smooth transitions between those points.

The plugs were checked constantly for signs of detonation. They did not exhibit any of the normal symptoms. It is possible there was detonation early on when the 16g was still on the car when the noise started.

I appreciate the responses and your feedback.
-Kevin
 
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