I thought this was a decent read and explanation of how to/why O Ring a head.

 

O Ring Cummins head

Thanks for that! I just brushed over it but I’ll definitely go back and read again.

About 3/4 through it.  Good article

Head gasket failure is not guaranteed above 40 psi like the article claims.  I know plenty of compound trucks (mine included) that are not o-ringed that make 70-75 pounds of boost with no head gasket issues.  It's all about timing and exhaust housing size.  The information about physically o-ringing the head is fantastic, but the information leading up to the good part of the article is wrong.

Edited June 18, 20186 yr by trreed

Forgot about this. I agree, the 1st portion of the article is fluff. I can only trust @trreed's info as I have no experience with this, and may never, but know you are running twins and real world experience always wins...But, I did like the pictures and thought it was interesting that the actual o ring channel was cut by hand and checked for depth. I assumed this was an automated process, and might be for some companies. The pictures were good in my opinion, showing this process. I understand the timing aspect of advancing the timing for a hotter burn, but struggle with the exhaust housing size and the role that it plays.

Yes, the pictures were fantastic.  Most shops manually cut o-rings I believe.

For the exhaust housing portion, the tighter the exhaust housing, the quicker the turbo spools, which means the torque comes in early in the power band, and torque is what breaks things. Low RPM, lots of timing, and a tight exhaust housing make for a sh*tload of cylinder pressure, and that makes head gaskets blow.  Conversely, the larger the exhaust housing, the later the torque comes in.

I'm assuming the guys who wrote this article saw studs that were improperly torqued or were just pulling **** out of their asses.

Edited June 18, 20186 yr by trreed

2 hours ago, trreed said:

Yes, the pictures were fantastic.  Most shops manually cut o-rings I believe.

For the exhaust housing portion, the tighter the exhaust housing, the quicker the turbo spools, which means the torque comes in early in the power band, and torque is what breaks things. Low RPM, lots of timing, and a tight exhaust housing make for a sh*tload of cylinder pressure, and that makes head gaskets blow.  Conversely, the larger the exhaust housing, the later the torque comes in.

I'm assuming the guys who wrote this article saw studs that were improperly torqued or were just pulling **** out of their asses.

So your setup is smaller turbos? and your timing is retarded back enough to be safe and run lower cylinder pressures?

LOL, with articles such as this, you have to know they pull stuff out of their asses, because they use a shop to outsource each different task, and create a "summary" that becomes the published article. Or they weren't running head studs to begin with, and swapped to twins and that is where the true head gasket issues showed up

I have a 62/75 setup.  Just optioned both turbos with tighter housings for better spooling characteristics. My injectors dictate higher timing numbers as well for a complete burn.  So I'm a case of someone who should be having head gasket issues due to my setup but I haven't had any issues as of yet.

Cool. That same article was in Diesel Power's May issue. Very interesting.

Money money money