Injectors keep lifting with built motor?

[dansdieselp]

How would lifting an injector trash a motor?

When the combustion leaking past the injector burns a hole through the injector bore into the intake port and into a coolant passage. Then flooding the intake air with coolant and hydro locking the motor while its spinning 3800rpm. Then cracked number two cylinder in the block and cracked crank between number two rod and two main.

 

[TNRGreene]

When the combustion leaking past the injector burns a hole through the injector bore into the intake port and into a coolant passage. Then flooding the intake air with coolant and hydro locking the motor while its spinning 3800rpm. Then cracked number two cylinder in the block and cracked crank between number two rod and two main.

Damn, mine is not that bad

And only 3800? oke: JK

 

[dansdieselp]

Damn, mine is not that bad

And only 3800? oke: JK

Yeah that was near the end of the pull according to the log. It went from 3800 to 0 in three frames. Didn't know it popped out or when during the run. It was locked up tight. This year was much better. Torqued the hold down studs to 32ftlbs. Then got motor warm. Broke nuts loose and retorqued to 32. No problems. Used arp lube on all friction areas as well.

 

[MarkBroviak]

SoCal makes a billet hold down and stud kit. I'm running his kit after trashing a motor cause of a injector lifting during a pull. 2011 was a short and expensive season. Stock hold down bent. No problems this year with Guys kit.

Same here, haven't had an issue as severe as yours but seen a few torched heads and destroyed injectors because of this. I use the SoCal kit on all my 700++hp builds with great results.

 

[kmax05]

Whats a set of billet studs from guy worth? i lifted 2 lly inj this yr:

 

[adeso]

For the guys with LB7s watch reusing cups that are stuck to the injector, I got to go back in and change out one that was really stuck to the injector 1000 miles in.

 

[Evan@InglewoodTrans]

In my opinion for the cost of new cups its not worth taking the chance with them especially if any are questionable .

 

[Slammed2007Lbz]

It seems LLYs have the biggest issue with this for some reason. My old lilly kept lifting injectors about once a week up till i sold it. The factory hold down bolts are WAY stronger then most think. They just wont snap. I had one froze up and had to heat it with a torch for about 10 minutes till i finally could break it loose and it didnt snap coming out. It was so damn hot and tight that i bent the bolt getting it out and it still didnt break. I have never seen a bolt bend like this one did and not break, it was bent about a 1/2 inch from the top to the bottom:roflmao:

 

[x MadMAX DIESEL]

37 is fine for an lbz head? Dan what do you mean 3800 to 0? Rpm? How could it lock a motor up

 

[JD Dave]

I got a set of billet hold downs and arp studs from DHD after lifting an injector. I think they were around $600 but I didn't want anything to happen again. I'm sure Danville sells them also.

 

[TNRGreene]

Ordering a set on Monday :thumb:

 

[juddski88]

That's outrageous to be honest. The hardware is 30 bucks! If you are seriously bending or breaking stock lly+ hold downs something in your setup should be revisited.

 

[juddski88]

I had a thread a while ago about this issue, but i had also cracked the injector body when it happened. I bought the hardware in bulk to stud the hold downs, but after retorquing the old bolts amd determining it had happened due to tuning, i am determined to see how far the stock, overtororqued bolts can be pushed...so far so good now

 

[kmax05]

What do you tq the stockers too?

 

[TNRGreene]

That's outrageous to be honest. The hardware is 30 bucks! If you are seriously bending or breaking stock lly+ hold downs something in your setup should be revisited.

Like what? The bolts are not bending or breaking. I've tried new stock bolts & upgraded ones, all the pads are in & I've noticed a few of the orings being trashed. The bores in the head are clean & new coppers. I'm assuming it's going on all the time but only really an issue when the injector fails, copper crushes or the hold down is fatigued enough from use.

 

[juddski88]

The copper can wear enough to leak just from extreme rail pressure. any knocking from a bad injector or electrical issue or the vibration within the injector (harmonics) from high pressure deforms that copper. Once that leaks, the oring is done. But orings have come out of stock trucks, stock tunes, messed up too, so how can you be sure it is attributed to this issue? Is it just coming out torn or is it missing?

If your injector is failing and that's when you are having copper sealing issues, there is the correlation you are looking for.

 

[x MadMAX DIESEL]

Only times i ever had this problem was because of a tune.

 

[TNRGreene]

The copper can wear enough to leak just from extreme rail pressure. any knocking from a bad injector or electrical issue or the vibration within the injector (harmonics) from high pressure deforms that copper. Once that leaks, the oring is done. But orings have come out of stock trucks, stock tunes, messed up too, so how can you be sure it is attributed to this issue? Is it just coming out torn or is it missing?

If your injector is failing and that's when you are having copper sealing issues, there is the correlation you are looking for.

Everything you say makes total sense. I get this & am not argueing with any of this other than how can you prove all of the above is not from a flexing hold down causing this. A flexing hold down would have the same symptoms. The guys that have had this problem claim it's fixed with the new hold downs. Or was it a bad injector?

We have not changed tuning since last year this time

 

[TNRGreene]

amd determining it had happened due to tuning,

What did you change that you think fixed it?

 

[juddski88]

We rescaled the sensor and instead of commanding 180mpa we commanded 178mpa. More was changed but the rest was done to spool the charger faster and fix erratic timing and pressure. When i cracked the injector and pushed it out, we had modified the tune we made in Denver, just to get a quick fix in place to test the new motor at our event in Sept. later, we found that it was not doing what we commanded it to do...at any time, therefore we started from fresh a week later.