Injectors keep lifting with built motor?

[05Monsterdmax]

Built my motor, went dual fueled yahta yahta on a s472 billet. Had an issue getting a good seal on the injectors when I first built the motor, ended up removing the powder and all was well for a bit while I babied it. Got about 1/2-3/4 throttle the other day on my mid tune (600) and had a back injector lift on driver side and start soaking the manifold in fuel. Anyone else had an issue getting them to seal good? Tq at 22ftlbs, bore was clean(I didn't use the gm injector bore cleaning kit) but they wasn't dirty either. I used a soft bristle wand and spin it in the bore then shop vac them out, inspected and looked clean of any debris. But keep having this issue anytime its beat on somewhat. I hate to spend 150-180 bucks on the kent Moore cleaning kit. Injectors are 40% also. Any ideas?

 

[RPM Motorsports]

You sure the pads are in place?

 

[Stingpuller]

Injectors

22 ft lbs is not enough. Injectors should be 37 ft lbs. If it has lifted the cups a few times you may have to redo the heads. It will eat the seat area in a short time.

 

[DIESELMAFIAPER.LB7]

I wrench them down more then 22 also lol i go way tight on tq

 

[redws6rocket]

I think his is an lly, I have seen guys use red loctite on both sides of the copper washer with luck. Or does arp make studs for an lly injector hold down?

 

[juddski88]

Mcmaster sells the stuff to stud it cheeeaaap. I've got a couple "kits" here...

 

[TNRGreene]

does arp make studs for an lly injector hold down?

Yes but the actual hold down flexes also

 

[TNRGreene]

Mcmaster sells the stuff to stud it cheeeaaap. I've got a couple "kits" here...

BTW how much? & ship me a set :thumb:

 

[adeso]

I have had good luck with the stuff I got from SoCal for my LB7

 

[messejme]

Someone makes a billet hold down kit and IIRC ARP makes a stud kit. Mcmaster Carr is good quality but standard grade hardware where as ARP uses there own custom metallurgy.

 

[dmax711]

Mcmaster sells the stuff to stud it cheeeaaap. I've got a couple "kits" here...

x2

 

[dansdieselp]

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.

 

[juddski88]

While ARP may have "custom metallurgy", the hardware from McMaster is aircraft grade and certified too.without looking it up again, i remember the tensile strength being something like 200k lbs

 

[DMAXchris]

You cant re-use the bolts. Buy new ones and you'll be fine.

 

[juddski88]

Those stock bolts can be reused Chris, they are not TTY

 

[Dirtymaxx03]

i hope they arent TTY......or i will have some issues later

 

[hondarider552]

Are LB7 and LLY injector hold downs the same TQ # ?

 

[DMAXchris]

Those stock bolts can be reused Chris, they are not TTY

Mine wouldn't seal and we could torque them to 50 ftlbs! Glad one didnt snap! We replaced them with brand new ones and it's been all good since. I think they can stretch after a few re-torques, especially if you go past the 22ftlbs.

 

[juddski88]

I've torqued mine to 40+ several times now. I agree they do stretch, but I've never snapped one nor had sealing issues like that

 

[TNRGreene]

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.

How would lifting an injector trash a motor?