Forged Redeye Engine Failure :( Why????

[16GoManGoHC2]

Some engine 101 diagnoses for those interested in learning.
I was asked by someone for my opinion on engine failure. These pictures tell tales.
Photos are of a set of billet main caps that were fitted to strong Redeye block. All premium parts were used, Callies Compstar Crank, Boostline Rods, Wiseco Custom Pistons, ARP Studs, etc. These main caps held down by ARP main studs pictured, One would think about a bullet proof rotating assembly right? Nope!! So what happened? The tell tail is in these pictures. Anyone care to guess what went on here? Tune was right on, was making over 1500 to the wheels twin turbo. Had multiple power settings in the tune, 1000, 1300, 1500. On 1500 it went BOOM. No detonation, no nothing showing bad in the logs, all was great then BANG, disaster. What is seen here? And what needs to be better next time and why? (Aside from 4 bolt main caps on at least the center 3 caps).

 

[vortecd]

Top cap in 1st picture was on backwards or notched on wrong side?

 

[BULL]

I'm seeing some fretting that on the mating surface that doesn't look good...

 

[Jack_Toepfer]

I believe the #1 cap in the first picture is just turned 180* compared to the others for the picture. I believe this because the tang witness mark on the opposite side is where it should be from the bearing in the block. If that bearing wasn’t lined up properly it would have witnessed on the same side of the cap as the tang slot, and would have been a quick catastrophe, not one that only exposed itself at 1500hp.
The hone marks on the caps lead me to believe the bore was line honed with these caps before fitting, that they weren’t just slapped in there. Ideally this was done with the appropriate hardware installed.
1500whp is pushing it, even on a “strong Redeye” block, ain’t it?
244-5400 is probably the right main studs.
Did Demon supply the other ARP hardware? Do they recommend stock hardware for the side cross bolts? I don’t see as much ARP lube as I would expect, but I imagine that was washed away with runtime.
I would have expected thicker caps on 2,3, and 4 not just 3.
I agree with Bull, not sure why there is anything on the mating surface.
I’m not convinced anything in these pictures failed

 

[16GoManGoHC2]

Top cap in 1st picture was on backwards or notched on wrong side?

Cap orientation was correct and is correct in the pictures, 1 on top (front cap) to 5 on the bottom

I'm seeing some fretting that on the mating surface that doesn't look good...

You’re correct in noticing a difference from the caps machined block mating surfaces. But that’s not fretting, but correct it’s not good.
What caused that different look?

I believe the #1 cap in the first picture is just turned 180* compared to the others for the picture. I believe this because the tang witness mark on the opposite side is where it should be from the bearing in the block. If that bearing wasn’t lined up properly it would have witnessed on the same side of the cap as the tang slot, and would have been a quick catastrophe, not one that only exposed itself at 1500hp.
The hone marks on the caps lead me to believe the bore was line honed with these caps before fitting, that they weren’t just slapped in there. Ideally this was done with the appropriate hardware installed.
1500whp is pushing it, even on a “strong Redeye” block, ain’t it?
244-5400 is probably the right main studs.
Did Demon supply the other ARP hardware? Do they recommend stock hardware for the side cross bolts? I don’t see as much ARP lube as I would expect, but I imagine that was washed away with runtime.
I would have expected thicker caps on 2,3, and 4 not just 3.
I agree with Bull, not sure why there is anything on the mating surface.
I’m not convinced anything in these pictures failed

Cap orientation is correct as mentioned above to vortecd.
Cap installation was done correctly, line bored and then line honed. Bearing clearances were ample for the HP targeted, it was a purpose build, builder knew what it was going to see at max. Timing was very conservative, it didn’t need lots of timing to get to the target power levels. Fuel was good and tested E85.
Why do caps 2, 3, and 4 look worse than 1 and 5? Thicker caps on 2, 3, and 4 would not have helped, not as configured at least.
The engine builder did choose all the parts.
The problem is in the pictures, nothing truly failed, but it led to the failure at the 1500 hp level. So what in the pictures is the culprit?

 

[SilverBillet]

The proof is out there.

 

[BULL]

There is something seriously wrong with this surface, while the picture might be misleading, there's something there that absolutely shouldn't be...




Upper left corner of this surface is "unhealthy"





Question is, what the hell caused that???


Or worse yet, was it like that when it got installed/torqued down???

 

[16GoManGoHC2]

There is something seriously wrong with this surface, while the picture might be misleading, there's something there that absolutely shouldn't be...




Upper left corner of this surface is "unhealthy"

View attachment 178657



Question is, what the hell caused that???


Or worse yet, was it like that when it got installed/torqued down???

Bull, you were somewhat correct in post #3 above. It is a type of fretting, its fretting corrosion. But how? It’s surrounded by constant oil splash, how could it corrode?? I’ll let goggle AI explain it since it does such a good job.


Fretting refers to wear, corrosion, or damage occurring between two tightly fitted metal surfaces subjected to slight oscillating motion or vibration. It commonly causes surface degradation in engineering applications like bearings, gears, and fasteners. It can also mean worrying or expressing distress (synonyms: fret, stew, pine).

• Engineering/Industrial:
  Occurs in components like aircraft wing/fuselage joints, orthopedic implants (knee/hip replacements), wind turbine pitch bearings, and bolted joints.
• • Mechanical Mechanism: Caused by high contact pressure combined with low-amplitude vibration (often 30–150
    μ
    m), leading to "fretting corrosion," where debris oxidizes and acts as an abrasive, say ScienceDirect.com and Fractory.

So how could this “motion or vibration” be happening? I mean their studs, torqued to probably somewhere around 85-95 ft lbs or more, that’s allot of clamp load on an about 1/2” diameter stud!! Could the cap really be moving around with that type of clamp load?? How could it lead to an engine failure?? Sooooooo what in the pictures could cause that but not fail? (Yet at least) What is that material that looks to be welded to that caps mating surface in picture Bull posted as “unhealthy”??

 

[16GoManGoHC2]

The proof is out there.

Yes!! It is!!

 

[16GoManGoHC2]

Hint, there’s also something odd in the top of the caps too in the picture posted in post 1, picture5, the last picture.

 

[BULL]

Hint, there’s also something odd in the top of the caps too in the picture posted in post 1, picture5, the last picture. View attachment 178661

There is discoloration that supports the corrosion explanation.

My best stab in the dark for the corrosion is a high-humidity area and/or acidic oil from lack of changes.

 

[SilverBillet]

Center cap has a threaded hole that doesn’t look lined up with the rest of them @16GoManGoHC2 ?

 

[BULL]

And the inconsistency in the machined mating surface (and why not ground?) doesn't much impress me either.

Even if not ground, those surfaces should be at least a 16 or 32 finish, and consistent.

Even accounting for line honing, those caps need to not move around, and that machined finish is shit for stability...


.02

 

[stonewall]

Some engine 101 diagnoses for those interested in learning.
I was asked by someone for my opinion on engine failure. These pictures tell tales.
Photos are of a set of billet main caps that were fitted to strong Redeye block. All premium parts were used, Callies Compstar Crank, Boostline Rods, Wiseco Custom Pistons, ARP Studs, etc. These main caps held down by ARP main studs pictured, One would think about a bullet proof rotating assembly right? Nope!! So what happened? The tell tail is in these pictures. Anyone care to guess what went on here? Tune was right on, was making over 1500 to the wheels twin turbo. Had multiple power settings in the tune, 1000, 1300, 1500. On 1500 it went BOOM. No detonation, no nothing showing bad in the logs, all was great then BANG, disaster. What is seen here? And what needs to be better next time and why? (Aside from 4 bolt main caps on at least the center 3 caps).


View attachment 178631 View attachment 178632 View attachment 178633 View attachment 178634 View attachment 178636

The mating surface to block looks like crap also. This surface should fit each block and cap without gaps, this surface appears to be very poor which would not make a very uniform loading when torqued.

 

[stonewall]

16GoManGohHC2 Just what did fail, rod brg. throw a rod, crank brake, you said it blew at 1500hp but that doesn't say what? that would shine light on where to look for the problem. LOL

 

[vortecd]

There is discoloration that supports the corrosion explanation.

My best stab in the dark for the corrosion is a high-humidity area and/or acidic oil from lack of changes.

Being the hp level, car is probably 95% track so not enough miles for lack of oil changes