PSA: CB Performance EFI Dual-Port Endcastings

[JVance]

Regarding the bolts that hold the fuel-rail to the end-casting, please replace your 6mm x 10mm bolts with 6mm x something longer.

Of that 6mm x 10mm bolt, about 2.5mm of the bolt passes through the fuel-rail retaining bracket; about 2.5mm of the bolt passes through the untapped portion of the boss on the end-casting; and, about 1mm of the bolt has insufficient thread (the end of the bolt where the thread tapers down to the minor diameter). If you're into rules of thumb, the length of engagement (at ~4mm) is less than the diameter of the bolt (at 6mm).

What *may* happen: fuel-rail pressure multiplied by the torque of the fuel-rail retaining bracket, plus engine vibration, may lead to the threads stripping out of the boss in the end-casting. If this occurs, your engine will take a gasoline shower.

I avoided disaster this afternoon, despite leaking several gallons of fuel onto my engine, cylinder heads, header, and turbo over the course of ~1.5 miles. The bolt retaining the fuel rail on the 3/4 head stripped out the 4 threads it was holding onto. I was able to scavenge a longer 6mm bolt elsewhere from my car to re-secure the fuel-rail, as there is at least 5mm more thread down within the boss of the end-casting that simply never touches the shorter, 10mm-long bolts. This allowed me to drive on without requiring a tow home. So, for those of us running these end-castings, please secure your fuel-rail with a longer bolt than the 6mm x 10mm bolts supplied by CB Performance. A 6mm x 15mm bolt is cheap insurance...really REALLY cheap insurance.

[QuickKafer]

Wow Dude!  Scarey stuff! 

Are you talking about the hex head bolt?

Scott Faivre

[JVance]

Yep. The end-casting is threaded deep enough, so just run a longer bolt for some added security and piece of mind.

[Mark Lawless]

Thanks for the heads up, I will make sure that all manifolds leaving from now on will have the proper length bolts.

I and CB apologize for the inconvenience and possible catastrophe that was thankfully avoided.

[JVance]

Thanks, Mark!

"An ounce of prevention is worth a pound of cure." -Benjamin Franklin

[Jason Foster]

Thanks for the heads up, I will make sure that all manifolds leaving from now on will have the proper length bolts.

I and CB apologize for the inconvenience and possible catastrophe that was thankfully avoided.

  Now THAT is customer service!  Very stand up of you to admit a flaw and ensure it is corrected.  Only other thing I see could be done is replace this gentlemans end castings as his now have stripped threads.  Good Job guys!

[JVance]

  Now THAT is customer service!  Very stand up of you to admit a flaw and ensure it is corrected.

FWIW, I understand there could be variation in how the castings are drilled/tapped. If the threads were cut to the top of the boss, the 10mm-long bolt would be long enough. But with threads recessed .100" in the bore of the boss (at least in my castings), there were not enough threads engaged with the provided bolts. Those who already have the end-castings should check to see if they're just hanging on by a few threads.

Only other thing I see could be done is replace this gentlemans end castings as his now have stripped threads.  Good Job guys!

Mark's pledge to address the issue on their existing inventory is more than fine for me. I applaud those efforts. However, I have welded and match-ported my end-castings, so replacing them would be a larger inconvenience than repairing them. I have a couple of options (leaning towards either a steel insert or a stud) which are cheap and easy, so I'm good