2013 F300XCA top seal blown

[dradams1]

That is the million dollar question. The way it looks to me based on the original appearance of the seal and looking at the retaining bracket-it seems the pressure in the crank case pushed it up partially.

Hopefully, it will be resolved this week and I'll post back exactly what I hear.

[tmann45]

Thanks, looking forward to hearing the rest of the story.

[boscoe99]

The crankcase is vented to the air intake system. High blowby pressure would more than likely just blow the vent hose off the valve cover or intake silencer.

My bet is that high oil pressure dislocated the seal.

Oil pressure at 3000 RPM is nominally 85 psi. That is quite a bit of pressure.

[dradams1]

Good to know about the venting. I am learning a lot through all of this.
Thanks

[dradams1]

Final verdict - new short block being installed currently. A Cylinder was damaged when oil was lost.

[boscoe99]

Ever wonder how the design got approved by engineering management without a retainer being used to keep a seal the place, when loss of that seal can lead to catastrophic engine damage?

I am wondering if old school engineering folks retired and some new know-it-all young bucks took over engineering. Seal retainer? We don't need no stinkin seal retainer. We can save ten cents a motor by not using a retainer.

Glad you got a new block. Hope you are back up and running.

[tmann45]

We can save ten cents a motor by not using a retainer.

Glad you got a new block. Hope you are back up and running.

And don't forget about the 3 ounces weight they saved in the lightest weight race.

[boscoe99]

And don't forget about the 3 ounces weight they saved in the lightest weight race.

Speaking of weight, the Offshore and SHO models used a plastic ring to close the gap between the lower unit and the propeller. To save weight. It did not work. Distorted due to exhaust gas temperature. It has been replaced by a metal ring. At about $85 bucks a pop.

Who's brilliant idea was that?

Japan has some strange ass engineers, if they can be called that. I apologize if I have offended any real engineers.

[tmann45]

Japan has some strange ass engineers, if they can be called that. I apologize if I have offended any real engineers.

Did not offend this engineer.

And Japan is not the only country with that problem. I'm currently driving a German SUV that is prone to steering wheel shake, started with the 2011 models. They just came out with a TSB on how to fix, took them 4-years. The wheel hub has to be at a certain rotation for mounting the wheel, and you have to make up the lug bolts by hand, no impact wrench.

[rodbolt17]

its about the same seal design that's been around about 60 yrs that I know of.
why it backs out on some and not all I don't know.
could be a bore ID or seal od mismatch.

years ago we had a smart arse young anganeer at a machine shop I worked at.
he sent down a drawing for me to prototype.
the ID was larger than the OD.

I took him a bag of metal shaveings for him to sign off on.

same anganeer that wanted a 32 finnish on a gray cast iron bore.

guy had a degree yet had never run a lathe or a mill.
lots of book learnings but it took us a few years to actually teach him.
eventually he learned to maybe ask some of the guys that had to actually machine the stuff if there was a better faster way.

same engineer that drew a firing pin mechanisim.
had a cylinder with a spring loaded pin.
pin and body had a .062 hole that the assy workers had to line up left and right as well as up and down to insert the shear pin.
once I figgeured out that idiotic setup I went to the engineer and explaned while I was machining the pins it would be faster and esier to assemble if I cut a .064 groove in the pin rather than add another drill operation and the assy aggrevation.
most the engineers I have worked with were decent folks. some easier to work with than others.
about the same with Drs.

[boscoe99]

One more.

I forget to mention the weight savings that Yamaha achieved on the Offshore and SHO models by eliminating part of the thrust bearing. That worked out real well for them also.

[rodbolt17]

on the SHO they also saved weight by not painting the block.