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Stock Evo 6 with Evo 8 ECU, Intake, TBE, Grimmspeed 3 port, ID 2000 injectors, Denso COP, Asnu 330 lph. Motor blew leaving a hole in the block where rod #3 used to live. 93 octane.
tuned about 100 2.0L 4-cylinder engines of various manufacture, and perhaps 50 assorted inline 6 and V8 configurations each.
At sea level in Florida climate (somewhat humid and usually "hot" ambient 80*F~)
About max timing I've ever used on solo 93 octane daily driver combos, from 18psi to 29psi is 9 degrees.
Even with 50/50 meth water around 500rwhp on a 122 cubic inches, still using about 9 degrees of timing at 28psi of boost by 5500+,
maybe just barely trailing into 10* maybe 10.2*~ roughing out after 7000rpm moving to 8 grand, another degree is acceptable.
If the air inlet temperature was reduced significantly I could see another degree fit, but IMO it would be gratuitous at that point.
The idea is to use minimum timing that gets the tune within 5-10% of max while holding EGT below a known maximum for the position of the EGT sensor.
i.e. max turbine inlet temp by specification for Borg Warner EFR series is near 1320*F
Stock Evo 6 with Evo 8 ECU, Intake, TBE, Grimmspeed 3 port, ID 2000 injectors, Denso COP, Asnu 330 lph. Motor blew leaving a hole in the block where rod #3 used to live. 93 octane.
As stated by KingTal0n, you are running way too much timing on 93.
I don't even run that much timing on E85, let alone 93 ... Evo 9 likes 9* up top ... Reduce it or you will be seeing bubbles in the overflow tank soon.
I don't think that timing is the culprit here, at max boost timing looks about right. There are other reasons that can cause the type of damage you mentioned, namely an undetected spun bearing, hard driving while a rod bearing is spinning could cause the rod to detach cracking the block in the process.
I don't think that timing is the culprit here, at max boost timing looks about right. There are other reasons that can cause the type of damage you mentioned, namely an undetected spun bearing, hard driving while a rod bearing is spinning could cause the rod to detach cracking the block in the process.
Let me guess, that's what somebody told you after they tried 15* of timing on 93 octane
"It must have had a bad bearing"
Yeah, every engine that fails has a bad bearing, but how does it get bad in the first place?
Advanced timing hammers the rod bearing with excess cylinder pressure as the piston is nearing TDC. The issue is compounded when owners install aftermarket headgaskets which tolerate higher than acceptable pressure.
A good fraction of total cylinder pressure responsible for applying torque to the crankshaft after TDC is produced and rising prior to TDC, such that only a slight offset in timing (a couple degrees) is enough to move the pressure peak too close to TDC.
Stock Evo 6 with Evo 8 ECU, Intake, TBE, Grimmspeed 3 port, ID 2000 injectors, Denso COP, Asnu 330 lph. Motor blew leaving a hole in the block where rod #3 used to live. 93 octane.
Pump gas is a “Crap Shoot”, consistent octane of 93 isn’t a reality. ZZA your map isn’t far off imo, but you could ramp it down a faster from 90~100 load are kinda high for pump gas. Also to be safe your at full boost 4000 rpm peak torque timing of 3 degrees on pump might be a little strong. Remember the base timing of the older evo’s can be off somewhat. The other issues I’ve seen are cars that ran fine with a tune for years then blew up from detonation. I attribute this to carbon build up in the combustion chamber. A fresh motor will always take more timing than a motor with deposits in it. They hold heat in the chamber as well as cause hot spots leading to detonation even with safe tuning. I suggest a water meth kit, your pistons will stay clean, and you make more reliable power.
I have no doubt this map worked well at one point without detonation, but mix in a bit of bad fuel and carbon deposits it’s gonna rattle.
Advanced timing hammers the rod bearing with excess cylinder pressure as the piston is nearing TDC.
Correct!
Another thing would be if the rod bore itself was just a little too over-sized and out of spec, causing a lack of bearing crush once the proper rod bolt stretch was reached. Those engines are just time bombs from the get go.
Let me guess, that's what somebody told you after they tried 15* of timing on 93 octane
"It must have had a bad bearing"
Yeah, every engine that fails has a bad bearing, but how does it get bad in the first place?
Advanced timing hammers the rod bearing with excess cylinder pressure as the piston is nearing TDC. The issue is compounded when owners install aftermarket headgaskets which tolerate higher than acceptable pressure.
A good fraction of total cylinder pressure responsible for applying torque to the crankshaft after TDC is produced and rising prior to TDC, such that only a slight offset in timing (a couple degrees) is enough to move the pressure peak too close to TDC.
"Yeah, every engine that fails has a bad bearing" you're joking...correct?
Bearings can fail for a variety of reasons, oil starvation, wrong bearing clearance, metal shavings, accidental downshift, to name a few
If you're theory is correct then we'd end up with the same timing table regardless of the type of fuel being used. Providing an engine is forged & well built then timing can be maximized providing there is no detonation, that's when using pump fuel. However, when using racing fuels or Ethanol then MBT is the only limit for timing. If a bearing shall fail because of excess torque then simply the engine not built well.
"Yeah, every engine that fails has a bad bearing" you're joking...correct?
Bearings can fail for a variety of reasons, oil starvation, wrong bearing clearance, metal shavings, accidental downshift, to name a few
If you're theory is correct then we'd end up with the same timing table regardless of the type of fuel being used. Providing an engine is forged & well built then timing can be maximized providing there is no detonation, that's when using pump fuel. However, when using racing fuels or Ethanol then MBT is the only limit for timing. If a bearing shall fail because of excess torque then simply the engine not built well.
Its your theory about bearings, not mine. I was making a joke from your saying "maybe a bad bearing made the bearing bad" you basically said maybe the engine was bad, thats why the engine was bad. It's a nonsensical statement.
Putting the majority of the peak cylinder pressure near TDC has the effect of damaging all manner of components, and giving the best highest output dyno graphs.
Just because you can push max timing and get a peak number does not make it smart or safe." Not built well " has nothing to do with a failure related to peak pressure.
"not built well" is stuff like rings that don't seat, sloppy machine work, etc...
The material itself has to fail for a high temperature and pressure to have any altering affect, which means the materials are what is failing, which means they are being improperly utilized. It's a tuning/configuration/setup issue, not an engine building issue.
Its your theory about bearings, not mine. I was making a joke from your saying "maybe a bad bearing made the bearing bad" you basically said maybe the engine was bad, thats why the engine was bad. It's a nonsensical statement.
Putting the majority of the peak cylinder pressure near TDC has the effect of damaging all manner of components, and giving the best highest output dyno graphs.
Just because you can push max timing and get a peak number does not make it smart or safe." Not built well " has nothing to do with a failure related to peak pressure.
"not built well" is stuff like rings that don't seat, sloppy machine work, etc...
The material itself has to fail for a high temperature and pressure to have any altering affect, which means the materials are what is failing, which means they are being improperly utilized. It's a tuning/configuration/setup issue, not an engine building issue.
Settle down Francis, both of you are totally speculating on this whole ordeal.
Could have been tune or motor related you’ll never know. Maybe the guy ran 87 octane or maybe he ran his junk low on oil..........or maybe a thousand other things. Let it go.
Honestly. When I go to get a junkyard engine for turbo application, especially a V8, I want the higher mileage, more worn out engines.
It means compression will be a little lower, better for more boost. The engine will be looser and tolerate a higher rpm and a thicker oil.
overall, worn out engines are the way to go if you plan to push a stock bottom end to some limit (rpm or boost)
If the motor is built, of course everything changes. My recommendations are for daily drivers and stock engines with fragile cast pistons.
Originally Posted by 2winscroll
Settle down Francis, both of you are totally speculating on this whole ordeal.
Could have been tune or motor related you’ll never know. Maybe the guy ran 87 octane or maybe he ran his junk low on oil..........or maybe a thousand other things. Let it go.
I never speculated on why the engine blew up. Only made a joke because I saw this:
1st guy : "hey my engine threw a rod (bad rod through block)"
2nd guy : "maybe the rod bearing was bad"
I was like lmao wut
Its like if this happened:
1st guy: Hey my headgasket blew
2nd guy: maybe the headgasket was bad
I mean seriously, how does a rod bearing or head gasket get bad in the first place. Of course if one or the other blows up, its officially bad at that point rofl
i.e. every engine with a thrown rod, has a bad rod bearing at that point (its pretty safe and useless to suggest)
Last edited by KingTal0n; May 17, 2019 at 09:26 AM.
tuned about 100 2.0L 4-cylinder engines of various manufacture, and perhaps 50 assorted inline 6 and V8 configurations each.
At sea level in Florida climate (somewhat humid and usually "hot" ambient 80*F~)
About max timing I've ever used on solo 93 octane daily driver combos, from 18psi to 29psi is 9 degrees.
Even with 50/50 meth water around 500rwhp on a 122 cubic inches, still using about 9 degrees of timing at 28psi of boost by 5500+,
maybe just barely trailing into 10* maybe 10.2*~ roughing out after 7000rpm moving to 8 grand, another degree is acceptable.
If the air inlet temperature was reduced significantly I could see another degree fit, but IMO it would be gratuitous at that point.
The idea is to use minimum timing that gets the tune within 5-10% of max while holding EGT below a known maximum for the position of the EGT sensor.
i.e. max turbine inlet temp by specification for Borg Warner EFR series is near 1320*F
I can't speak for other platforms, but 9 degrees at redline on the stock ECU is extremely low for an Evo8 running boost levels close to stock on 93 octane. High teens is too high. Low to mid-teens is pretty normal around 7500 rpm. Maybe a bit lower if your car is knock prone or the air temps are extreme (that's what AIT modifier tables are for). Running 9 degrees at redline would give you extremely high exhaust temps in the manifold and likely risk melting something in the turbo if you were running sustained high RPMs (like on a track day). Just want to get that out there for any newbies who might be reading this thread. I don't know anything about Hondas or other boosted platforms, but I do know the Evo8 pretty well from 16 years of ownership, including dozens of track days without a problem on 93 octane.
Sep 11, 2018, 11:39 AM
