[XXX ZL1]

Originally Posted by JANNETTYRACING

It is common when there is detonation present.

We have never had a problem with that in the engines we tune or build.

I might not have the highest dyno numbers but my stuff lives.

I say it all the time, we don't chase numbers, we make the engine happy.

These things are so detonation prone that I'm same as you. I'd rather give up 20 hp and they live. Not worth chasing that last degree, cause at some point its going to knock the rods out. lol

[SOCAL.M6.ZLE]

Originally Posted by XXX ZL1

These things are so detonation prone that I'm same as you. I'd rather give up 20 hp and they live. Not worth chasing that last degree, cause at some point its going to knock the rods out. lol

I agree 100%...

My builder recommended roller tip rockers to help prevent the oblong valve guide wear... anyone else running roller tip rockers?

[ZL1_1LE]

Originally Posted by ZL1_1LE

I thought I read a couple of members on here mentioning they were trying to steer you into a better direction with the timing of your previous tune but you didn't want to stray from what the previous tuner had done. Hopefully you've moved on from that tuner and into the arms of one that isn't as jannety said "chasing numbers".....unless of course I am completely off base here then disregard lol

Originally Posted by Joshinator99

I’ll go with A based on previous discussion about timing. My second and third guesses are A, and also A.

So he was that guy, he seems to be responding to every one elses thoughts on the problem but the actual culprit. Seems if that is the case, we'll be seeing another rebuild after 9k miles again.

[KingLT1]

Originally Posted by XXX ZL1

These things are so detonation prone that I'm same as you. I'd rather give up 20 hp and they live. Not worth chasing that last degree, cause at some point its going to knock the rods out. lol

Not on ethanol....

[2023_ZL1-AUTO]

Originally Posted by KingLT1

Not on ethanol....

through out all my mods, and all my tunes, from E60 to straight E85, with over +785rwhp, I've never record knock !!!

[ZL1_1LE]

Originally Posted by KingLT1

Not on ethanol....

Originally Posted by 2023_ZL1-AUTO

through out all my mods, and all my tunes, from E60 to straight E85, with over +785rwhp, I've never record knock !!!

That's because E60 and E85 are ethanol.....

[JANNETTYRACING]

Originally Posted by 2023_ZL1-AUTO

through out all my mods, and all my tunes, from E60 to straight E85, with over +785rwhp, I've never record knock !!!

This brings up a good Point.

You can have a fuel that is detonation resistant enough, where knock sensors do not pick it up, but still have cylinder pressure peak at wrong crank degrees in the cycle.

Ideally and this can vary a couple degrees based on engine design, Peak Cylinder pressure should occur around 15 Degrees after top dead center to produce MBT.

What is MBT, Mean Best Torque.

At each RPM and Load, you can Locate MBT by holding the engine at any rpm and load then doing a Hook test to see where highest torque is produced.

This is what the OEMs do when building calibrations.

In testing I have pushed Ethanol fuels way beyond MBT and did not record knock from the sensors but I see different signs that is for a much deeper conversation.

Direct injection engines on good fuel are hard to make knock, if you do you could be 6 to 7 degrees too far from MBT.

One of the good practices are to back timing down until you measure a significant loss in torque.

It is always safer to operate on the lower side of the hook than the higher side.

I hope this helps this conversation.

[ZL1_1LE]

Originally Posted by JANNETTYRACING

This brings up a good Point.

You can have a fuel that is detonation resistant enough, where knock sensors do not pick it up, but still have cylinder pressure peak at wrong crank degrees in the cycle.

Ideally and this can vary a couple degrees based on engine design, Peak Cylinder pressure should occur around 15 Degrees after top dead center to produce MBT.

What is MBT, Mean Best Torque.

At each RPM and Load, you can Locate MBT by holding the engine at any rpm and load then doing a Hook test to see where highest torque is produced.

This is what the OEMs do when building calibrations.

In testing I have pushed Ethanol fuels way beyond MBT and did not record knock from the sensors but I see different signs that is for a much deeper conversation.

Direct injection engines on good fuel are hard to make knock, if you do you could be 6 to 7 degrees too far from MBT.

One of the good practices are to back timing down until you measure a significant loss in torque.

It is always safer to operate on the lower side of the hook than the higher side.

I hope this helps this conversation.

You are a lock box of great information Jannetty this platform is very lucky to have your knowledge! So would it suffice to say that (going back to OPs issue on a barely used motor) that his timing was too high from the tuner and that it could have been masked by other factors within the tune?

[SOCAL.M6.ZLE]

Originally Posted by ZL1_1LE

So he was that guy, he seems to be responding to every one elses thoughts on the problem but the actual culprit. Seems if that is the case, we'll be seeing another rebuild after 9k miles again.

I appreciate your interest and concern... no finger pointing here please.
My goal with sharing my "fortification / rebuild / cam swap" process was to share what I have learned and explain why I am upgrading the things I am upgrading.

The valve guides have had me worried for a while... Katech has clearly been very vocal about the issues there, even in low mile cars.

Trust me, I did not plan to re-fresh so soon, but the more I learn about the platform, talk to different tuners / builders / it was clear that if you want to make 900rwhp, reliably, there are ALOT of things you need to do to get there.

Most of the industry is focused on "bolt on power" when in reality, if you spoke to 5 competent engine builders, but guess is that they would all tell you fix and improve many short block and head issues before going that far...

Which unfortunately makes playing this game alot more of a financial investment... but if you are all about doing it right, you gotta pay not just for the power.... but you gotta pay for the durability.

I am sure TED can chime in on his efforts to make 900+ rwhp Di only, low boost, and some of the OEM shortcomings he safe guarded against.

I pulled my engine out at 2K miles to do my "at the time" very budget H/C package. That was 3 years ago now, and boy have a learned alot since then... What I can say with extreme confidence is that I would have done 85% of my build differently if I started with a fresh build today.

It's that learning curve that I, and many others have tried to steer people towards... to avoid some of the back and forth I have done myself...

The cost of doing all the back and forth, testing part, spending 3 months to tweak several parts of the car, just to do it all over again 3 months later for the sake of science, is the overhead of becoming a better resource and technical advisor to you all.

Although I could live 3 more lives and still not know as much as many of you on the board hear like Ted, King, Mega, David, and more... The more eyes, the more testing, the more mistakes we all collectively make, and share... the more we learn and grow as a community!

That said... my new short block will be rated for a reliable 1,200hp... which means it should be very happy at 900whp... and yes, I am going to be running the super boring BTR Stage.I cam (with a fuel love shaved down to 32% for a happier HPFP)

The goal here is to semi-maximize Di, Stock Ported Blower and Stock Cubes... while of course, continue to test and revise my cooling products, and several other new goodies coming down the pipeline.

Whats kind of funny, is that so much of the "extra" work I decided to do to this build was based on the fact the BMR Coil Over LCA's were on back order... so I used those 6 weeks to tear into no less that 5 other projects... which ultimately lead to finding a "bad ass" engine builder while looking for a local flow-bench, to discussing platform reliability, JV short block collabortaion, ideal LT4 cams, custom grinds, all the issues he has seen with the factory long block over the years... and voila!

I think my last question may have been lost in the mix.... but did anyone else decide to try out some roller tip rockers? My builder says they do wonders for preventing the oblong valve guide wear... Let me know!

[ZL1_1LE]

Originally Posted by SOCAL.M6.ZLE

I appreciate your interest and concern... no finger pointing here please.
My goal with sharing my "fortification / rebuild / cam swap" process was to share what I have learned and explain why I am upgrading the things I am upgrading.

The valve guides have had me worried for a while... Katech has clearly been very vocal about the issues there, even in low mile cars.

Trust me, I did not plan to re-fresh so soon, but the more I learn about the platform, talk to different tuners / builders / it was clear that if you want to make 900rwhp, reliably, there are ALOT of things you need to do to get there.

Most of the industry is focused on "bolt on power" when in reality, if you spoke to 5 competent engine builders, but guess is that they would all tell you fix and improve many short block and head issues before going that far...

Which unfortunately makes playing this game alot more of a financial investment... but if you are all about doing it right, you gotta pay not just for the power.... but you gotta pay for the durability.

I am sure TED can chime in on his efforts to make 900+ rwhp Di only, low boost, and some of the OEM shortcomings he safe guarded against.

I pulled my engine out at 2K miles to do my "at the time" very budget H/C package. That was 3 years ago now, and boy have a learned alot since then... What I can say with extreme confidence is that I would have done 85% of my build differently if I started with a fresh build today.

It's that learning curve that I, and many others have tried to steer people towards... to avoid some of the back and forth I have done myself...

The cost of doing all the back and forth, testing part, spending 3 months to tweak several parts of the car, just to do it all over again 3 months later for the sake of science, is the overhead of becoming a better resource and technical advisor to you all.

Although I could live 3 more lives and still not know as much as many of you on the board hear like Ted, King, Mega, David, and more... The more eyes, the more testing, the more mistakes we all collectively make, and share... the more we learn and grow as a community!

That said... my new short block will be rated for a reliable 1,200hp... which means it should be very happy at 900whp... and yes, I am going to be running the super boring BTR Stage.I cam (with a fuel love shaved down to 32% for a happier HPFP)

The goal here is to semi-maximize Di, Stock Ported Blower and Stock Cubes... while of course, continue to test and revise my cooling products, and several other new goodies coming down the pipeline.

Whats kind of funny, is that so much of the "extra" work I decided to do to this build was based on the fact the BMR Coil Over LCA's were on back order... so I used those 6 weeks to tear into no less that 5 other projects... which ultimately lead to finding a "bad ass" engine builder while looking for a local flow-bench, to discussing platform reliability, JV short block collabortaion, ideal LT4 cams, custom grinds, all the issues he has seen with the factory long block over the years... and voila!

I think my last question may have been lost in the mix.... but did anyone else decide to try out some roller tip rockers? My builder says they do wonders for preventing the oblong valve guide wear... Let me know!

A very long winded answer to not answer the question, so I'll keep mine short. I agree that the amount of knowledge a small majority on here carries is incredible! The adage "buy once cry once" and doing your research on tuners/parts/builders prior to spending thousands in cash just to have to redo it all over again with the amount of knowledge already out there for this platform is astounding. I'm only asking specifically about the motor issue you're having and how it relates to the amount of timing you were using so that others that come after us don't make the same mistake.

[SOCAL.M6.ZLE]

Originally Posted by ZL1_1LE

A very long winded answer to not answer the question, so I'll keep mine short. I agree that the amount of knowledge a small majority on here carries is incredible! The adage "buy once cry once" and doing your research on tuners/parts/builders prior to spending thousands in cash just to have to redo it all over again with the amount of knowledge already out there for this platform is astounding. I'm only asking specifically about the motor issue you're having and how it relates to the amount of timing you were using so that others that come after us don't make the same mistake.

Oh... I am following you know, currently under the weather and didn't realize you were asking for my timing... I will check when I get home, but the peak torque timing has been changed several times as the build has evolved... I believe I am seeing 26 peak with E60 but ill check to see how that ramps in for everyones benefit!

I found a screen shot of an old log from 2023 and I am seeing 20-21 degrees at 3,600 rpm. I'll check my PC when I get home!

[SOCAL.M6.ZLE]

Originally Posted by ZL1_1LE

A very long winded answer to not answer the question, so I'll keep mine short. I agree that the amount of knowledge a small majority on here carries is incredible! The adage "buy once cry once" and doing your research on tuners/parts/builders prior to spending thousands in cash just to have to redo it all over again with the amount of knowledge already out there for this platform is astounding. I'm only asking specifically about the motor issue you're having and how it relates to the amount of timing you were using so that others that come after us don't make the same mistake.

Yes sir... always trying to learn form others mistakes whenever possible...

How much timing are you running? and who did your tuning?
PM me if you want to keep that private.

[JANNETTYRACING]

Originally Posted by KingLT1

Agree but when I tweaked his tune, I found 40-50wtq by adding 3-4 degrees midrange, but lost 15whp peak pulling timing from 29-30 down to 27. This was when it made around 800whp... So, I don't think it had too much timing (23 degrees) in the 3-5k rpm range if torque jumped that much. If I added that timing and it gained little torque I would have pulled it back out. Generally, you don't need as much timing around peak torque as Ted mentioned. But if it responds like that then the engine is happy. The setup has since been retuned by someone else, so this might be meaningless to share.

Edit*

Want to touch up on my prior post. Another reason why I suspect mechanical issue being culprit is because the mentioned valve guide wear could have been allowing excess oil into the cylinders and that could cause detonation. Be curious to know if any rods are bent. Far as tuning, look up all the vehicles equipped with a LT4 and compare the differences. The Cadillac BW is tuned for 30 degrees peak (Seems Crazy!!). Then let's circle back on oil...GM has recommended like 3 different oil weights for the 6.2 engine. 0-20, 5-30, 5-40. So, there isn't no way Amsoil caused it.

My final opinion is premature valve train wear allowed oil to contaminate the cylinders and potential metal in the oiling system.

Thanks for sharing.

Peak torque is where things can get ugly in a hurry, I purposely leave them a litte low there becuase in the event you get some bad gas it won't tear it self apart, it is easier on the engine components where we are doubling factory rated HP and Torque.

Torque is Mean on parts due to cycle time if that makes sense.

Example, I once destroyed a manual transmission (cleaned the teeth off 5th gear) in my Diesel truck by installing an overdrive on the back of the trans, and operating the truck at Peak torque 1400 rpm vs 1800 rpm on the highway.

The higher torque at lower rpm spreads out the power strokes hammering the parts like a giant sledge hammer.

This roughly illustrates what I am talking about.

Typically the extra torque is useless on a street tire anyway, (spinning ain't winning).

As we get further from peak torque we need to roll in more timing to keep cylinder pressure up and carry the torque and is not where the destruction occurs.

Im 61 this year, I started working on and tuning engines of all kinds starting at 5 years old thanks to my Grandfather, Tool maker and Genius and in my eyes.

I share the 56 years of engine tuning experience to help people understand why I do what I do.

[ZL1_1LE]

Originally Posted by JANNETTYRACING

Thanks for sharing.

Peak torque is where things can get ugly in a hurry, I purposely leave them a litte low there becuase in the event you get some bad gas it won't tear it self apart, it is easier on the engine components where we are doubling factory rated HP and Torque.

Torque is Mean on parts due to cycle time if that makes sense.

Example, I once destroyed a manual transmission (cleaned the teeth off 5th gear) in my Diesel truck by installing an overdrive on the back of the trans, and operating the truck at Peak torque 1400 rpm vs 1800 rpm on the highway.

The higher torque at lower rpm spreads out the power strokes hammering the parts like a giant sledge hammer.

This roughly illustrates what I am talking about.

Typically the extra torque is useless on a street tire anyway, (spinning ain't winning).

As we get further from peak torque we need to roll in more timing to keep cylinder pressure up and carry the torque and is not where the destruction occurs.

Im 61 this year, I started working on and tuning engines of all kinds starting at 5 years old thanks to my Grandfather, Tool maker and Genius and in my eyes.

I share the 56 years of engine tuning experience to help people understand why I do what I do.

There is a dozen ways to skin a cat, and as we've already covered everyone's cars are different, modifications/parts/use case etc. Great info in here thus far.

edit: Jannetty where is that post you quoted from lol? I'm trying to go back and read on what page for more context but couldn't find it.