injectors = broken crank ?
- Thread starter BIG DIPPER
- Start date
I sent two set of stock sticks in for professional testing, and they were pretty good. This was done with complete injector assys, not tips.
New injectors have etched data inscribed on them indicating their flow. So it would be apparent that Bosch does test each stick.
The stock nozzle holes are about 15 microns.
New injectors have etched data inscribed on them indicating their flow. So it would be apparent that Bosch does test each stick.
The stock nozzle holes are about 15 microns.
I find this to be one of the most interesting posts in this thread. What about swapping some wires in the injector harness and a custom cam to change the firing order?
So why are people getting their stock injectors tested by a third party and finding huge deficiencies?
Who bought stock injectors from Bosch and found huge deficencies?
That doesnt make much sense to me that Bosch cant even get there injectors rightAFAIK they have the money and equipement to be able to test there own stuff.Geuss not
For the longest time the dmax used a 7 micron filter. It was only last march that they came out with the new OEM filter.
I thought they changed back in 04 to a 3 micron to try and fix all the lb7 injector issues.
So the white filters where actually 7 and the blue are the 3?
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You might be on to something.
Also, LBZ+ engines run more external balance weight than LLY/LB7 does. But the rotating assy isn't much heavier, IIRC. LBZ's aren't breaking cranks.
It would be interesting to assemble an LB7/LLY with LBZ harmonic balancer and flexplate and see how it does, but I can't do it since I'm now 100% LBZ.
Big Dipper didn't start the thread. Trentnell did after taking some posts out of the other thread to have a discussion but the discussion went to hell in a hand basket.
I am not sure what Matt what was trying to do and I take his opinion with a grain of salt because he doesn't have any evidence that injectors cause crank failures.
To me for an injector to be flowing diffrent than all the rest the Pistons and rods are going to show signs of damage and or brakeage long before the crank would :cool2:
You are correct , I was hoping it could be discussed civily because it is a good topic that alot of speculation is thrown about with not much real info . there has been alot of good tech in this thread minus a few of the bashes.
Thanks, I didn't know that at first. I can only see what is posted.
You should take EVERYONE's opinions with a grain of salt on the internet.
Nobody has detailed information either way as far as what causes it. Massive injector imbalance has been noted on an engine that broke a crank, but who knows if that was the reason? For now, that example has caused a lot of concern, and has pushed many people into getting their injectors balanced. It certainly can't hurt.
The Dodge guys started their Injector Wars years ago, and we are just starting to see it.
Obviously, I'm going to do my best to keep it to a dull roar on this site. Yeah, some people aren't going to like that, but I'm willing to take the heat (as long as nobody is surprised when I get fed up).
Somebody pointed me to these two threads to stop the fighting. I do not like moderating. And obviously I don't like potshots aimed at me either.
I expect the diesel shops who post on this site to exercise common courtesy regardless of whether they are site vendors or not. It's not DP, where the site vendors must behave, but the non-site vendors don't have to.
I no longer sell injectors, I buy them. If InjectorShopX wants to claim I get them for free, they are fibbing. In one case I tuned a big charger truck in exchange for injector nozzles, but the $ = $.
Kat and I debate constantly whether we should post data about our racing setups. It often causes us to be the target of scorn that is seldom deserved. This thread is just another example. According to InjectorShopX and his customers, I hide my engine problems, I get everything for free, and I'm running injectors now to support InjectorShopZ. For what? I didn't do shit.
The reason the Dmax community is started to go underground is mostly caused by diesel shops trying to shut folk up on the internet. Most often, it's the Secret Squirrel shops that use this tactic. If you hassle folk for publically discussing their trucks, they you will have to pick up the phone to call them in private. I'm going to do my best to halt that.
What some of you do not understand is that I refer people to Big Dipper, TTS, and other shops who I'm "supposed" to be trying to ruin. If the shop fits that customers needs, I will continue to support them. Parts is parts; the label on a box does not change it's content.
I have broken a Steel crank in a SBC @500hp and honestly think it was due to stress it was a few years old and was tired of hanging in there. With the diminishing quality of metal available today, and all of the chinese shit being imported stuff like this will continue to happen. Its the same deal we are having with flat tappet cams. Due to lower sulfur and zinc levels in oil and weaker steel we are breaking parts. If you are going to race get used to it.
Some things to ponder.
1 This thread was a spin off of another. Big Dipper did not start it
2 From what I gather these injectors did not come from Big Dipper.
3 From what I gather the crank was the same from the first Ross piston build. Early LB7 crank. It was not like this crank had an easy life and only a few passes on it.
Gm has at least 4 variations of the Dmax crank. They knew there was a strenght issue. Going to an LLY crank is a good idea.
4 To Micks interesting point that maybe we need more mass. This is what GM did when going from the LB7 to the LLY. So you might be on to something there.
1 This thread was a spin off of another. Big Dipper did not start it
2 From what I gather these injectors did not come from Big Dipper.
3 From what I gather the crank was the same from the first Ross piston build. Early LB7 crank. It was not like this crank had an easy life and only a few passes on it.
Gm has at least 4 variations of the Dmax crank. They knew there was a strenght issue. Going to an LLY crank is a good idea.
4 To Micks interesting point that maybe we need more mass. This is what GM did when going from the LB7 to the LLY. So you might be on to something there.
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I know of someone that had Exergy(old Bosch guys) test their injectors. Checked good. Two months later the tested way worse. Same people, same test. Less then 50 hours of run time. Contamination can trash injectors. Things like water and dirt in the fuel can take there toll. Even with good quality fuel pumping fluid at 26000+ psi thru them cause wear. They may need redone later. I know my local HiPo Tractor pump shop likes to EDM, then hone , then run in, and then balance injectors because of this.
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Does anybody know roughly speaking, the crank models that are breaking the most? Worst to best? LB7 LLY LBZ etc?
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LB7 and LLY are similar, with the slight edge going to the LLY. LBZ/LMM crank is "significantly" stronger/heavier.
We don't generally flow test the injectors before hand if we are modifying them, unless we are looking for a problem. Bench time is expensive and at a premium.
We disassemble, clean, do a quick inspection under magnification of some the key areas, to rule out the unuseable cores and then modify. The real time is spent after modification getting the set balanced at all the data points in flow as well as making sure the spray pattern is correct.
Matt,
Sorry about not giving you a flow sheet. Kind of a crazy day when you did the pick up and it slipped my mind. I have a copy here in your file and will forward ASAP.
Guy
No worries - wasnt concerned at all. Would be neat to see though!
Also, so sorry about the mortor stand, Im bringing it down this Monday, will see you mid-day.
Carry on, the discussion here is good.
Also, so sorry about the mortor stand, Im bringing it down this Monday, will see you mid-day.
Carry on, the discussion here is good.
Just weighed some cranks including the front gear.
LB7 77.3 lbs
LLY 77.0 lbs
LBZ 75.5 lbs
Don't read too much into this as the LBZ has smaller dia. counter weights to clear the extra mass of the LBZ piston, due to the increased pin boss diameter which is there to accomodate the bronze bushing.
The end result is that the LBZ has larger weights on the flywheel and damper to make up for the loss of counter weight on the crank and the fact that the LBZ piston is 100 grams heavier than the LB7/LLY.
So is the lbz crank alot stronger than the earlier models; enough to change out what i have now?
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I had the blue filter on my '05 and on my current '07. Like Simon posted, I'm pretty sure the 3 micron filter came out years ago-not last march.
Exactly!! New out of the box injectors that have never been exposed to any contamination will be much different from ones that have been run even only for a short time. Everytime you open the fuel system, you expose it to microscopic contaminants. For those that weren't aware, 50 micron is the limit to what can be seen with the human eye. GM fuel filters filter down to 3 micron - to put it in persepective.
are you provoking an arguement?:baby: if thats the case i will pass. we are having tech discussion about cranks and i asked a question about lbz cranks; if its ALOT stonger to justify changing it out from what i have now (early lb7).