Lb7 limits

2004LB7

Well-known member
Dec 15, 2010
6,280
1,683
113
Norcal
that answer is unknowable. no one here has a cristal ball that can tell you how long an engine is going to last. though experience has told us you are on borrowed time at that power level. but no one here can tell you exactly how much time you have left or how much damage may have already been done. if you can't afford to rebuild it now, then turn down the power until you can.
 
  • Like
Reactions: DAVe3283

LSxBakakos

Member
May 29, 2022
78
9
8
Illinois
I definitely can't argue that. every engine is different and every outcome can be as well. I was just trying to get a feel of what timeline some of the 600+ guys had that way I could make a better call on wether it's worth the risk or stepping it down. But maybe I'll just have to deal with the boredom and leave it in 3 until I've got the cabbage to throw start piecing together a shortblock
 

MAXX IT OUT

<<<IT WORKS
Mar 1, 2013
1,774
34
48
Des Moines, Iowa
The engine's limits are right before it blows up, so by that time it's to late to worry. The real limit is on your wallet and time. If neither of those are a problem, beat it like it owes you money and have a new engine ready for when that one blows up.
 

TheBac

Why do I keep doing this?
Staff member
Apr 19, 2008
15,271
1,564
113
Mid Michigan
Im literally asking if it'll live for a year or two at that level before it scatters itself. I do plan on building an engine in the future but don't want a paperweight for a while. So if you guys really think it's just gonna blow itself I'll either play with fire or turn it down and be bored with the power level again
As said earlier, it'll live as long as it lives. If you're hell-bent on Tune 4, then run it, but at least you'll know there could be consequences.
 
  • Like
Reactions: LSxBakakos

LSxBakakos

Member
May 29, 2022
78
9
8
Illinois
I can't believe this has gone to page 2 with the same question being asked.:rolleyes:
Mike that's because I wanted to see how long others have held together at that level vs "it's gonna blow up after 550". That's not what I asked for.
The engine's limits are right before it blows up, so by that time it's to late to worry. The real limit is on your wallet and time. If neither of those are a problem, beat it like it owes you money and have a new engine ready for when that one blows up.
Guess we'll just see what happens then. After what I spent on fuel and blowing the built trans 200mi later (had 50k on it) it's been an expensive year. So I'm trying to push it as hard as I can without another failure, seems to be that day will come sooner than later though unless I turn it down.

Bac idk why it won't let me reply to you as well but I suppose that's my answer I'll figure it out one way or another lol
 

2004LB7

Well-known member
Dec 15, 2010
6,280
1,683
113
Norcal
maybe you asked the wrong question. instead of asking how long others think your engine will last. maybe you should have asked how long others engine lasted at xxx power level before major hardware failure. could have done a poll too with different levels of miles. but you went your route and this is the result
 

LSxBakakos

Member
May 29, 2022
78
9
8
Illinois
I makes me happy when I step on the skinny pedal. Never dyno'd.
I know that feeling lol
maybe you asked the wrong question. instead of asking how long others think your engine will last. maybe you should have asked how long others engine lasted at xxx power level before major hardware failure. could have done a poll too with different levels of miles. but you went your route and this is the result
I'll take blame for that, probably could've worded it better. Just a little aggravating when I come to the forums for advice, first post and get half assed or douchey answers, but equally my fault. Wanted to hear the 600+ trucks and what time spans they had out of theirs just to ballpark my 💩📦
 

clrussell

pro-procrastinator
Sep 23, 2013
5,903
358
83
Spray it and pray 🤷🏻‍♂️ If you’ve got unburnt fuel you might get to that 11.99.. or take everything out of the truck and lighten it as much as possible. Then spray it big and see what happens.

You only live once.

Trucks are fun.


I say send it. If it pops put another stock used bottom end in it then Turn it down.
 

08lmm72mm

Active member
May 13, 2019
528
164
43
Saskatchewan, Canada
I know that feeling lol

I'll take blame for that, probably could've worded it better. Just a little aggravating when I come to the forums for advice, first post and get half assed or douchey answers, but equally my fault. Wanted to hear the 600+ trucks and what time spans they had out of theirs just to ballpark my 💩📦
If it helps I've been on tune 4 for about 9 years and over 100k with a 72mm and 45overs. Added the 12mm cp3 last year.
 
  • Like
Reactions: LSxBakakos

Bdsankey

Vendor
Vendor/Sponsor
Feb 1, 2018
3,895
1,067
113
Neenah, Wisconsin
My LLY lived for ~18mo at a 2400-2800us tune with 60% inj/10mm pump/Danville 68 Stg2R 4094 before it gave up and that was beating it 24/7 like it owed me nothing. Various sled pulls (~40) all over 4000rpm, lots of burnouts, trips to Mexico etc. Highest I dyno'd was 687hp/1186ft-lbs.

When I knew something was wrong it started to white smoke cold and would actually lope in reverse at idle backing up some trailers into winter storage. Pulled the injectors because balance rates were way off and Exergy noted no issues with them. Did a compression test (should've done it first) and had lower than average compression across the board with one cyl being super low. Had 1 straight rod, 6 tweaked, and 1 visibly bent.



Moral of the story, nobody can predict it's failure/lifespan. If you can't afford to build it now OR be without the truck then I personally would turn it down.
 
  • Like
Reactions: LSxBakakos

LSxBakakos

Member
May 29, 2022
78
9
8
Illinois
Spray it and pray 🤷🏻‍♂️ If you’ve got unburnt fuel you might get to that 11.99.. or take everything out of the truck and lighten it as much as possible. Then spray it big and see what happens.

You only live once.

Trucks are fun.


I say send it. If it pops put another stock used bottom end in it then Turn it down.
I had the goal set on 11s full weight/street trim so I'll probably see what 4 does and if it doesn't crack 11s maybe take the chance lol.
My LLY lived for ~18mo at a 2400-2800us tune with 60% inj/10mm pump/Danville 68 Stg2R 4094 before it gave up and that was beating it 24/7 like it owed me nothing. Various sled pulls (~40) all over 4000rpm, lots of burnouts, trips to Mexico etc. Highest I dyno'd was 687hp/1186ft-lbs.

When I knew something was wrong it started to white smoke cold and would actually lope in reverse at idle backing up some trailers into winter storage. Pulled the injectors because balance rates were way off and Exergy noted no issues with them. Did a compression test (should've done it first) and had lower than average compression across the board with one cyl being super low. Had 1 straight rod, 6 tweaked, and 1 visibly bent.



Moral of the story, nobody can predict it's failure/lifespan. If you can't afford to build it now OR be without the truck then I personally would turn it down.
That was exactly what I was looking to hear, because our driving style sounds the exact same. Abusive lmao.
 

Bdsankey

Vendor
Vendor/Sponsor
Feb 1, 2018
3,895
1,067
113
Neenah, Wisconsin
I had the goal set on 11s full weight/street trim so I'll probably see what 4 does and if it doesn't crack 11s maybe take the chance lol.

That was exactly what I was looking to hear, because our driving style sounds the exact same. Abusive lmao.
Just to make sure we're on the same page, it's not something I will ever recommend to a customer as I don't want my name tied to that recommendation.

It's like my parents always said growing, do as I say not as I do. We've done it many times (even gone above that) but every time it's been a close friend and everyone goes into it expecting it to not live long at all and is perfectly OK with that outcome.
 

LSxBakakos

Member
May 29, 2022
78
9
8
Illinois
Just to make sure we're on the same page, it's not something I will ever recommend to a customer as I don't want my name tied to that recommendation.

It's like my parents always said growing, do as I say not as I do. We've done it many times (even gone above that) but every time it's been a close friend and everyone goes into it expecting it to not live long at all and is perfectly OK with that outcome.
I figured I'll probably run it mild in the beginning of this season and crank it up towards the end if I'm feeling better about it. After the house I told myself I'll retire the truck from racing and get my nova in the works after that. Eventually when this thing kacks itself Id like to do a built short block, af cam, socal heads, compounds and have something that makes 4 digits. But one step at a time. Tuner seemed confident with what was pulled that 4 was relatively safe on 4 but wouldn't live there forever. 5 they were pretty stern on use it on reserve