Injector hold down bolts stretch?

[thunder550]

When I get into higher boost levels I start to get ticking coming from one of the cylinders. I'm 99.9% sure it's air getting past the copper injector seats. I tightened them a bit and now it takes more pressure to make the sound, but still does it. Do the factory bolts stretch? What can I do to get more seat pressure on the injectors to help them seal better?

 

[mike diesel]

Yes they stretch. And yes it sucks when one let's go.

 

[duramaxzak]

SoCal billet hold downs and stud's!

http://www.danvilleperformance.com/socal-diesel-billet-injector-hold-down-clamp-kit-05-2010/

 

[thunder550]

Found this thread. Post #11 specifically.
http://www.duramaxdiesels.com/forum/showthread.php?t=36888
I'm going to try a new set of OEM bolts for $30 and see what happens before I drop $650 on the stud/hold down kit :thumb:

Thanks guys.

 

[03_DMAX]

Studs/Billet hold downs are not needed at your power level. Get new oem factory bolts and torque to spec. Problem solved....

 

[Harbin_22]

I have reused the OEM bolts a dozen times or more and always lube and torque them and have yet to have a problem. Luck maybe?

 

[mike diesel]

I have reused mine a whole bunch too.

 

[jpowel29]

Billet Hold Downs and Studs seem expensive, until you lift an injector under boost.

 

[Harbin_22]

I'll be putting billet in my truck soon, but the stockers have served me well

 

[andy-stevenson]

Billet Hold Downs and Studs seem expensive, until you lift an injector under boost.

What can this do to an injector?

 

[Harbin_22]

It can and will torch the head if it lifts far enough

 

[bml2200]

Make sure there isn't a copper washer stuck in the bore as well. I've snapped a hold down bolt while torquing before, it sucks.

 

[Hot COCOAL]

I re-torqued then 2x and was fine and like others cleaned the threads and lubed them upon installation

The 3rd time was the "stretch point" for me, I wound up torquing them way past the factory spec to get them to seal under boosted cylinder pressure...

New ones will serve you well, no need for the SoCal hold downs...
But they are cool
:thumb:

 

[thunder550]

Everything was really clean, heads had just come back from the machine shop and looked brand new. I cleaned the crap out of the valve covers too before reassembling. I think the new bolts will help

 

[motoking_1990]

Do lb7s have this problem

 

[RPM Motorsports]

Make sure the injector hold down pad is in the valve cover, I've seen that a few times. We used stock bolts at 85psi boost all last season without issue. This season we lifted an injector and killed a head (more boost), luckily stock heads are cheap and easy to find:spit:.

 

[DMAX497]

Blew one of mine out this year... Tick way loud and fuel spitting out. The bolt stretched... So hell with it and have billett hold downs now.

 

[duramaxzak]

Do lb7s have this problem

Yes, it's more of a problem with LB7's because it lifts the injector cup also.

 

[Chevy1925]

make sure its not a boost leak or drive pressure leak first. it could be your drive pressure gauge your hearing (if its leaking)

 

[SilveradoTwins02]

Yes, it's more of a problem with LB7's because it lifts the injector cup also.

So with this said, when you add the screw in cups it greatly reduces the chance for lifting ?