4B11 engine failure documentation thread
Evolving Member
Joined: Oct 2009
Posts: 438
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From: SL, UT
The methanol controller is basically brand new, and of a new design from Snow, but my old one did fail at one point, so I wouldn't rule it out.
A methanol injection failure during 5th gear acceleration with near-full spool could have caused it. I'll definitely add in an injection fail-safe to my rebuild budget.
But to add, my tune doesn't really rely on the methanol injection, as I mentioned my total timing advance before. I've literally got it added as a piece of mind at the moment. The leanest it goes when methanol cuts out is 11.9-12.0 AFR, which isn't dangerously lean. Just enough to know to back off. BUT, 30+ psi on pump gas without methanol isn't exactly safe. And I was on crappy Missouri 91 octane at the time. Who knows? I'll start an engine tear-down and build thread once the time comes and link to it from here. I agree we should try to keep clutter out of this thread, even if everything here is partially relevant.
Last edited by UT_EvoX; Jan 15, 2010 at 06:12 PM.
I hate to continue analysis on just your engine failure in this thread... but where else can we do it 
.
I want to ask a few things. A) when did you get your car (there could have been a bad batch of rods, since there are many other X's over 500whp on stock rods). B) that certain conditions of a period of time can weaken anything. It could have started from something from the beginning (bad fuel pump), which may have weakened it to begin with? C) Bad luck?
.I want to ask a few things. A) when did you get your car (there could have been a bad batch of rods, since there are many other X's over 500whp on stock rods). B) that certain conditions of a period of time can weaken anything. It could have started from something from the beginning (bad fuel pump), which may have weakened it to begin with? C) Bad luck?
Evolving Member
Joined: Mar 2008
Posts: 443
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From: Atlanta Ga.
Good point... this is a second-hand methanol injection system from my other car, but I've yet to have any problems with it. I don't have a flow fail-safe, but I'm very vigilant about checking fluid levels to make sure the system is topped-off and working.
The methanol controller is basically brand new, and of a new design from Snow, but my old one did fail at one point, so I wouldn't rule it out.
A methanol injection failure during 5th gear acceleration with near-full spool could have caused it. I'll definitely add in an injection fail-safe to my rebuild budget.
But to add, my tune doesn't really rely on the methanol injection, as I mentioned my total timing advance before. I've literally got it added as a piece of mind at the moment. The leanest it goes when methanol cuts out is 11.9-12.0 AFR, which isn't dangerously lean. Just enough to know to back off. BUT, 30+ psi on pump gas without methanol isn't exactly safe. And I was on crappy Missouri 91 octane at the time. Who knows? I'll start an engine tear-down and build thread once the time comes and link to it from here. I agree we should try to keep clutter out of this thread, even if everything here is partially relevant.
The methanol controller is basically brand new, and of a new design from Snow, but my old one did fail at one point, so I wouldn't rule it out.
A methanol injection failure during 5th gear acceleration with near-full spool could have caused it. I'll definitely add in an injection fail-safe to my rebuild budget.
But to add, my tune doesn't really rely on the methanol injection, as I mentioned my total timing advance before. I've literally got it added as a piece of mind at the moment. The leanest it goes when methanol cuts out is 11.9-12.0 AFR, which isn't dangerously lean. Just enough to know to back off. BUT, 30+ psi on pump gas without methanol isn't exactly safe. And I was on crappy Missouri 91 octane at the time. Who knows? I'll start an engine tear-down and build thread once the time comes and link to it from here. I agree we should try to keep clutter out of this thread, even if everything here is partially relevant.
Sorry that was a little off topic.
1.) 17000 miles @ failure
2.) Hole through side of block, at least 1 broken rod. Led to an oil fire which destroyed 1/3 of my engine bay. No symptoms up until catastrophic failure.
3.) Stock rod was either defective or they simply cannot handle 32+ psi on a CBRD BB-X turbo. From what I can see currently, the rod split clean in half and the big end is still in tact.
Moral of the story, the stock rods are weak as hell. I honestly spiked to about 36-38 psi 3 times on 3 partial pulls when I had some mapping issues with EcuFlash. That probably produced a torque spike of ~500 lb-ft which weakened one of the rods.
Oddly, the failure happened in 5th gear under 1/2 throttle while passing somebody going under the speed limit on I-29. I would convert back to stock and make the dealer fix it, but I honestly don't want another stock block that is incapable of handling a decent 450-500 WHP.
No tuning issues. 2-3 counts of knock max. 11.6 AFR with a large shot of methanol/water. Very conservative timing. 30-32 psi straight across from 3500 to 7500 rpm.
Must have just been too much for the stock bottom end to handle. *shrugs*
I'll find out soon if it was rod bolt failure, but it honestly doesn't look like that is the case. Nor should it have been because I neither make much torque nor rev past 7600 rpm.
edit: There are my modifications:
CBRD BB-X turbo, ported exhaust manifold & turbine housing, Invidia DP/TP/N1 catback, Cobb Intake + Inlet hose
Custom UICP, Snow Performance CH3OH/H2O injection, AMS inline fuel pump, 1000 cc/min DW injectors, Cossy fuel rail (doesn't matter, but just illustrating the adequacy of my fuel system), replaced OEM fuel relay w/ green one
2.) Hole through side of block, at least 1 broken rod. Led to an oil fire which destroyed 1/3 of my engine bay. No symptoms up until catastrophic failure.
3.) Stock rod was either defective or they simply cannot handle 32+ psi on a CBRD BB-X turbo. From what I can see currently, the rod split clean in half and the big end is still in tact.
Moral of the story, the stock rods are weak as hell. I honestly spiked to about 36-38 psi 3 times on 3 partial pulls when I had some mapping issues with EcuFlash. That probably produced a torque spike of ~500 lb-ft which weakened one of the rods.
Oddly, the failure happened in 5th gear under 1/2 throttle while passing somebody going under the speed limit on I-29. I would convert back to stock and make the dealer fix it, but I honestly don't want another stock block that is incapable of handling a decent 450-500 WHP.
No tuning issues. 2-3 counts of knock max. 11.6 AFR with a large shot of methanol/water. Very conservative timing. 30-32 psi straight across from 3500 to 7500 rpm.
Must have just been too much for the stock bottom end to handle. *shrugs*
I'll find out soon if it was rod bolt failure, but it honestly doesn't look like that is the case. Nor should it have been because I neither make much torque nor rev past 7600 rpm.
edit: There are my modifications:
CBRD BB-X turbo, ported exhaust manifold & turbine housing, Invidia DP/TP/N1 catback, Cobb Intake + Inlet hose
Custom UICP, Snow Performance CH3OH/H2O injection, AMS inline fuel pump, 1000 cc/min DW injectors, Cossy fuel rail (doesn't matter, but just illustrating the adequacy of my fuel system), replaced OEM fuel relay w/ green one
Damn man that really sucks. Cant wait to see what you build up next.
a friend of mine had meth FP red, cams and such was tuned as well with supporting mods, injectors fuel rail and others. Doing about 40MPH the rod bolt broke Grenading the engine! 2 nice holes! So replace rod bolts and FP relays!
Evolved Member
Joined: Feb 2008
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From: Rhode Island
Later, Ken
I have seen a few come thru with bad motors. The bad relays are easy to find. usually have big holes in the block and catastrophic failure style. The Bad rings are a bit less common but just result in low compression
Account Disabled
Joined: Jan 2010
Posts: 344
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From: non of your business
I bet u it wasn't the meth that caused this problem if it was he would have fryied a piston and the rings...The problem was with the tune and the over boosting plus 12.o afr's is crazy i rather stick with 11.4 to be safe..
Evolving Member
Joined: Oct 2009
Posts: 438
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From: SL, UT
I'm starting to think my rod bolts actually failed, but I can clearly see a fractured rod cross section through the back of the block.
I found the other 4B11 thread that died from overshooting meth. Rod broke as well.
https://www.evolutionm.net/forums/ev...1-carnage.html
EDIT:... nevermind it was from NOS!
https://www.evolutionm.net/forums/ev...1-carnage.html
EDIT:... nevermind it was from NOS!
Evolving Member
Joined: Oct 2009
Posts: 438
Likes: 0
From: SL, UT
I found the other 4B11 thread that died from overshooting meth. Rod broke as well.
https://www.evolutionm.net/forums/ev...1-carnage.html
EDIT:... nevermind it was from NOS!
https://www.evolutionm.net/forums/ev...1-carnage.html
EDIT:... nevermind it was from NOS!
But yeah, too much methanol/water will result in combustion quenching at most. Methanol can be construed as just another fuel.
Evolving Member
Joined: May 2009
Posts: 174
Likes: 0
From: Gdansk, Poland, Europe
Stock rod was either defective or they simply cannot handle 32+ psi on a CBRD BB-X turbo. From what I can see currently, the rod split clean in half and the big end is still in tact.
Moral of the story, the stock rods are weak as hell. I honestly spiked to about 36-38 psi 3 times
Moral of the story, the stock rods are weak as hell. I honestly spiked to about 36-38 psi 3 times