injectors = broken crank ?

[GMC_2002_Dmax]

I see this thread has caused some people some heartache.......

I don't have anything other than an opinion just like everyone else, what I do have is a lot of experience tuning big stick trucks.

Not testing a set of injectors may or may not matter on a 500HP stock motor, it does in my opinion matter on a 1000HP build.

You can look at it this way, if you have a set that is within 3% on all eight at all flow mpa and mm3 you are running what some would refer to as a blueprinted set of injectors.

If you have a couple that are way up on flow in comparison you have effectively raise the cylinder pressure for those cylinders with more fuel being dumped in. You can argue the fact all day that it does not matter but in the end you have some cylinders making more power on the downstroke after combustion that the other cylinders do, that is the facts.

So if you follow the theory that more cylinder pressure=more HP/TQ then you are effectively loading the rod journals with unequal forces during the combustion/power stroke. Now I am no engineer but common sense tells me that if you were to load a crank with varying loads when you really want eight cylinders working in unison that something may happen that is not expected.

You could melt a piston, you could crack a piston, you could crack a crank.

These are all things that "could" happen.

Will they, I don't have enough statistical data to say definitively yes or no.

But I do know that we can make enough power to destroy an engine and a transmission very quickly.

You are all adults, it's your wallet, it's your truck, if you want to roll dice on substandard rods, poorly cut/coated pistons, no-name brand TC's or trans rebuild kits and take your truck to a hack shop with a dirt floor it's all on you.

I know if I am spending money I want it done right, that is why I trust people like Guy, Mike L, Dipper, Burkhardt, etc. These guys know their shit and stand behind their work.

Dipper has done both my transmissions and I would only use Guy or Burkhardt for my motor if and when I go that route.

Buyer Beware.

I have said what I need to.

 

[Trippin]

So is the lbz crank alot stronger than the earlier models; enough to change out what i have now?

I don't know that it is or not. Not as many high hp LBZ as there are LB7, so the data sampling is suspect.

 

[dmaxvaz]

I don't know that it is or not. Not as many high hp LBZ as there are LB7, so the data sampling is suspect.

Thank you for your honest oppinion. tell me this- if you weigh the lb7 balancer, crank, flexplate/flywheel, would those weigh close or equal to the same as the lbz crank,balancer, and flywheel/flexplate together since some parts are heavier and some are lighter between the 2 engines?

 

[McRat]

Last warning. If you want to start a fight in this thread, please don't.

There are lots of boards out there for fighting in tech threads. We have a list of lots of other diesel boards in Smoke Signals.

 

[dmaxvaz]

Last warning. If you want to start a fight in this thread, please don't.

There are lots of boards out there for fighting in tech threads. We have a list of lots of other diesel boards in Smoke Signals.

I am not trying to start fights with anyone, i think ive been pretty civil and have not attacked anyone. i am simply asking tech questions about an lbz crank; since this is what Guy does this day in day out. i have no alterior motives, i just want to know more thats all.:hug: i should just pm him and ask him, that way i dont offend anyone.

 

[Kat]

I am not trying to start fights with anyone, i think ive been pretty civil and have not attacked anyone. i am simply asking tech questions about an lbz crank; since this is what Guy does this day in day out. i have no alterior motives, i just want to know more thats all.:hug:

It wasn't directed to you

 

[dmaxvaz]

It wasn't directed to you

okay, disregard the post above then, thanks

 

[McRat]

Sorry about that. I deleted a post that was intended to start a fight between shops and had nothing to do with injectors causing crank failures.

 

[Mike L.]

DING, DING, DING, WE HAVE A WINNER! BIG DIPPER -i think the same way as you do on this. problem is ______ comes to the masses with this idea that injectors caused this crank breakage and because of this, send _______ all your injectors and everthing will be "right" when you get them back, because they have a pc of paper that comes back with them saying everthing is fine, but it wont state that your crank will not break because of the "balanced" injectors you just paid for, nor will it guarantee it wont break. i dont buy into this marketing scheme of things to corner the market in the injector buisiness , too bad alot of people do:rofl:

What would you call this?

 

[dmaxvaz]

What would you call this?

that balanced injectors wont guarantee a broken crank from not happening. i am not going to argue with you, hell i was even nice enough to give someone your #s on the dp, so please lay off of me

 

[McRat]

that balanced injectors wont guarantee a broken crank from happening. ...

That's kind of odd logic.

A sprinkler system won't guarantee your house won't burn down, so they don't do anything?

My $10,000 worth of safety equipment in my truck won't guarantee I won't get hurt or killed, so I should just remove it all?

Like I said before, nobody knows if massive injector imbalance can actually bust a crank. I suppose somebody should put together 10 Dmax engines with unbalanced injectors and run them until something breaks and see if the cranks are still good. But who will do that? Not me.

We could collect data instead, but as we can see by this thread, engine problems are to be scorned or hidden, so you'll never see correct data.

Everytime there is a thread about engine failures, only a very few that have had problems will admit to it. No big surprise there. If you admit to breaking stuff, you will get screwed on the internet. That's why most are discussed privately instead.

 

[Mike L.]

that balanced injectors wont guarantee a broken crank from not happening. i am not going to argue with you, hell i was even nice enough to give someone your #s on the dp, so please lay off of me

Stay out of my business. Do not recommend me to anyone. I do not want your name associated with me.
I have been told to leave you alone which I will. I am outa here.

 

[dmaxvaz]

That's kind of odd logic.

A sprinkler system won't guarantee your house won't burn down, so they don't do anything?

My $10,000 worth of safety equipment in my truck won't guarantee I won't get hurt or killed, so I should just remove it all?

Like I said before, nobody knows if massive injector imbalance can actually bust a crank. I suppose somebody should put together 10 Dmax engines with unbalanced injectors and run them until something breaks and see if the cranks are still good. But who will do that? Not me.

We could collect data instead, but as we can see by this thread, engine problems are to be scorned or hidden, so you'll never see correct data.

Everytime there is a thread about engine failures, only a very few that have had problems will admit to it. No big surprise there. If you admit to breaking stuff, you will get screwed on the internet. That's why most are discussed privately instead.

you have some good points and i agree Pat, the problem is that our intake tract is designed pretty weird and doesnt equally distribute the air equally to combust equally! so having balanced injectors is only one part of the equasion. maybe thats why some cylinders are taxed with more stress than others. in the future we will probably see sheetmetal intakes made to better distribute the air flow to the cylinders( like the banks intake log manifolds). some other thing to think about is when i went to school for becoming a diesel technician, we have learned that injectors are made in lots of whatever quantity, then are selected and are flow tested within 10% of each other and then the set are installed into the engine and run that way for hundreds of thousands of miles with no problems.

 

[mick]

you have some good points and i agree Pat, the problem is that our intake tract is designed pretty weird and doesnt equally distribute the air equally to combust equally! so having balanced injectors is only one part of the equasion. maybe thats why some cylinders are taxed with more stress than others. in the future we will probably see sheetmetal intakes made to better distribute the air flow to the cylinders( like the banks intake log manifolds). some other thing to think about is when i went to school for becoming a diesel technician, we have learned that injectors are made in lots of whatever quantity, then are selected and are flow tested within 10% of each other and then the set are installed into the engine and run that way for hundreds of thousands of miles with no problems.

I dont want to go too far off the subject here but I used to think this way as do alot of others about the stock intake manifold. But rethinking it now I wonder if there really is any different pressures or volumes entering the different intake ports considering that the entire manifolds are chocker block with x amount of boost just looking to go into any smallest orifice available. I ran a Banks Bighoss manifold that cost alot of dolars and looks like it would outflow the stock manifold by 2 to 1. I ran this with probably 10 different configerations with Turbos and SC's. Real story is we never made any more power anywhere with the Banks manifold. In fact we could never duplicate the power with the Banks manifold that we made with the stock one. Not wanting to put down Banks because I think they have alot of good products. And just maybe with Parralel Turbos it could work better but certainly the way we ran it, it made no improvement to performance at all.

 

[hoot]

Maybe engine just isn't able to handle the high power levels just by design. The Powerstroke 7.3 also had a point where it just blew up.

 

[racinmike77]

with the boost we run there is plenty of air sitting there waiting for the intake valve to open imo.

As for the injectors I think you guys are crazy to say that balanced injectors are the end all fix to crank failures.

 

[racinmike77]

That's kind of odd logic.
OK
A sprinkler system won't guarantee your house won't burn down, so they don't do anything?

A SPRINKLER IS CALLED INSURANCE

My $10,000 worth of safety equipment in my truck won't guarantee I won't get hurt or killed, so I should just remove it all?

THATS YOUR PERSONAL CHOICE

Like I said before, nobody knows if massive injector imbalance can actually bust a crank. I suppose somebody should put together 10 Dmax engines with unbalanced injectors and run them until something breaks and see if the cranks are still good. But who will do that? Not me.

YOU ARE ALMOST THERE

We could collect data instead, but as we can see by this thread, engine problems are to be scorned or hidden, so you'll never see correct data.

SO BUILD 10 MOTORS

Everytime there is a thread about engine failures, only a very few that have had problems will admit to it. No big surprise there. If you admit to breaking stuff, you will get screwed on the internet. That's why most are discussed privately instead.
MAYBE THEY ARE SCARED THAT THEIR BUILDER WILL BE BASHED AND SUPPORTING VENDORS PIMPED AT ALL COSTS?

If you ask silly questions you will always get silly answers.

 

[Brayden]

I haven't read the whole thread but I don't agree with the injector imbalance causing the failure. I think the crank has had a hard life, well over it's design intent, and that's racing.

The key questions to ask are.. What was the setup like before the injectors?

Long pulsewidth, high timing, high boost... Those all equal undue crank stress. We just built a motor that had a box tuner break a crank.

PS... Jay you owe me a phone call.

 

[MACKIN]

Maybe engine just isn't able to handle the high power levels just by design. The Powerstroke 7.3 also had a point where it just blew up.

Well thanks for your in-sight dumb dumb

How do you explain the or at what power level is "by design" that the engine can not handle when crank failures have happened or hasn't happened at varying power levels from less than 500 to in excess of 7/800 HP?

But frankly most of us KNOW where your in-sight is cumming from.

 

[duratothemax]

Well thanks for your in-sight dumb dumb

How do you explain the or at what power level is "by design" that the engine can not handle when crank failures have happened or hasn't happened at varying power levels from less than 500 to in excess of 7/800 HP?

But frankly most of us KNOW where your in-sight is cumming from.

hahahaha :rofl: