Injectors lifting

[SAC owner]

Hey guys, I have a LBZ that has a built engine I just finished. It has s475 over stock wcfab compounds, 45 over sticks, 10mm cp3 etc. I lifted a injector the other night brought it up to the shop and fixed it, all good now. The problem I am having is when I am on my big tune it is lifting injectors when fully spooled (maxes out 60psi gauge waiting on 100psi one) I get a tick such as a leaky exhaust manifold, as soon as I hear it I lift and it is fine no tick or noise. It only does this in the big tune,I guess I am going to have to spend some bucks on Socal hold downs. So why are some guys making 1000 plus HP and fine on stock hold downs and some like me at 700HP best (we just have baseline tunes in dyno time soon for fine tune) and lifting injectors?

Another bit of info is it was 15*F. out when it did this. I know boost pressure will go up as it gets colder.

 

[Ne-max]

Are you reusing the bolts? We always put new in no matter what

 

[melms23]

My LMM with the same setup took a couple tries on #8 and I thought it was my fault being my first time.

Turned out it has a knick out of the tip where it seated the copper washer. Never had a problem after that even with factory hold downs and bolts.

 

[SAC owner]

I am reusing the bolts. I will try the new OE bolts and hold downs first..

 

[Nickracer9]

It’s good to torque and retorque after a heat cycle. I cranked mine down pretty good after the specified torque wasn’t enough though.

 

[ikeG]

Is it the same injector each time?

 

[jpowel29]

Clean the injector bore/seat well. If you are already lifting injectors with cylinder pressure I would invest in the studs and better hold downs. I’ve seen a head get cut through like a torch from the injector lifting on a friend’s build. I had an injector seize up in the head due to excessive carbon build up from an injector lifting.

 

[SAC owner]

Is it the same injector each time?

no it is not

 

[IOWA LLY]

What are you torquing them to?

I torque to 24-26 ft lbs with lube and have never ever had an issue. I use stock hold downs and re-use bolts unless they are showing signs of corrosion.


Sent from my iPhone using Tapatalk Pro

 

[SAC owner]

Clean the injector bore/seat well. If you are already lifting injectors with cylinder pressure I would invest in the studs and better hold downs. I’ve seen a head get cut through like a torch from the injector lifting on a friend’s build. I had an injector seize up in the head due to excessive carbon build up from an injector lifting.

Everything is very clean and brand new, I have seen a truck in my shop with a torched head/stock not pretty also seized up injectors. I own a auto/diesel shop. I am very versed with mechanicals.

But I am new in the past few years to diesel performance, and it is much different than gas.

I guess I am really wondering why some guys making 1000+ hp with stock hold downs hold and others making 700hp don't hold.

It looks to be my only option to buy the socal hold downs, I just spent 24k on this truck.... Whats another 650$:rofl:

 

[SAC owner]

What are you torquing them to?

I torque to 24-26 ft lbs with lube and have never ever had an issue. I use stock hold downs and re-use bolts unless they are showing signs of corrosion.


Sent from my iPhone using Tapatalk Pro

I put them at 30ftlb with lube as well. all brand new stuff, heads injectors seals etc. The only thing I reused was the hold downs and bolts, guess thats the week point...

 

[IOWA LLY]

Well, not necessarily saying that is your problem, but there is a thing as over torquing. 30 ft lbs might have damaged the bolts, or even pulled the threads from the head.


Sent from my iPhone using Tapatalk Pro

 

[SAC owner]

Well, not necessarily saying that is your problem, but there is a thing as over torquing. 30 ft lbs might have damaged the bolts, or even pulled the threads from the head.


Sent from my iPhone using Tapatalk Pro

I could agree, the bolts and hold downs have been used 3 times as well..