Watcha P-Pump cummins go Boom!

[thrashingcows]

http://www.youtube.com/watch?v=d_8Fc9qAZcw

[ellis93]

Wow! Lots of fancy parts just went to schit!
Wonder what happened to it?

[thrashingcows]

My guess is too much fuel and air = Runaway! Eventually it built too much cylinder pressure and the head studs gave up the valiant effort of trying to hold all that cylinder pressure beneath the head.

[fatty]

I've seen this vid a few times before but never an explanation. I wish someone knew so I could quit wondering.

[Sutter1stgen]

Now I see why they wrap cable around pulling motors.

[Jonnylightening]

Yeah Ive seen this video before. Couldn't imagine that feelin seein that big of n investment blowin to pieces.

[dazedandconfused]

Last time I saw that video they said they were just starting the pull and had fully loaded it when it popped. They should have backed off at the .16 second mark when it really changed tone.

[stillsmokin]

Excessive back pressure... watch the exhaust balloon right before the motor goes bang. It takes a lot of heat and pressure to stretch exhaust pipe.

Hope the dyno operator had good insurance!

[RCCUMMINS89]

For the love all things holy do not tell all of these "professional" engine builders that over on Cummins forum.

Because drive pressure absolutely in no way is hard on head gaskets.

[dazedandconfused]

For the love all things holy do not tell all of these "professional" engine builders that over on Cummins forum.

Because drive pressure absolutely in no way is hard on head gaskets.

That's why their sthi is always screwed up

[Sutter1stgen]

For the love all things holy do not tell all of these "professional" engine builders that over on Cummins forum.

Because drive pressure absolutely in no way is hard on head gaskets.

Back when you and I started conversing on CF you had just blown you're head gasket a 3rd or ??? Time. And you were debating getting your head Oringed. I'm pretty sure I got questioned in that thread too.
High cylinder pressure, back pressure, and boost pressure are all different forces. Too much of all three has the potential to do something catastrophic.

[RCCUMMINS89]

In that thread it had to do with re surfacing the head and what it does to compression.....luckily bc was like uh.......yea, it doesn't change compression.

But, I've been told that I've been wrong about the drive pressure issue by one of the biggest turbo guys on cf. Pretty "crazy" to think that drive pressure has no affect on cylinder pressure.

[fatty]

I remember when the 6.7 first came out, people were blowing head gaskets left and right with the stock turbo and a tuner. Even with head studs. Then they started swapping to bigger turbos or adding an external gate and the problem went away.

[RCCUMMINS89]

Yes sir.... I too remember this.

[DMan1198]

There's one guy that's adamant that the only reason 6.7's blow hg's is because of the bigger displacement, and completely rules out timing, and drive pressure