Over-revved S54

[Jarvis]

I'm in the middle of the first year engine class at MassBay's BMW program, and I recently got to tear down an over-revved S54.

Pretty much all of the intake valves are fubar, and some of the exhaust valves are damaged a little also. Some valves bent so far out of place that they collided with the top of the piston, never making it down the extremely deep valve reliefs. A few of the shims that normally sit on top of the valve retainers were just bouncing around above the oil drain passages in the head. The force of the piston-to-valve contact sheared all the bolts off of the intake cam's sprocket that connects to the Vanos. Thought I'd share...

[hamann318is]

Ouch. Piloted by a champion driver no doubt.

[Jarvis]

Also, keep in mind that in the pictures shot through the intake passages are of the head minus the cams... the valves should be flush with the valve seats :crazy:

And speaking of cams, check out the crazy profiles of the stock S54 ones, and the sheared off bolts:

[Jand3rson]

Damn, that's painful to look at. A money shift, perhaps?

[fretburnr]

Damn, that's painful to look at. A money shift, perhaps?

s54? i would say not just money, but Ca$h money :pimp:

[Brew]

A money shift, perhaps?

No doubt. Pretty much the only way to over-rev an engine with a rev limiter. And yes, "money" shift for us dealer techs, because its almost always customer pay.

[Jarvis]

No doubt. Pretty much the only way to over-rev an engine with a rev limiter. And yes, "money" shift for us dealer techs, because its almost always customer pay.

Except this was from a two year old car, so you get to work at warranty pay rate. Sucker.

[Brew]

Except this was from a two year old car, so you get to work at warranty pay rate. Sucker.

Except the customer gets to pay for everything because they geniously shifted from 5th to 2nd at 100mph. Not warranty. Bitch.

[Jarvis]

In this specific case, you're wrong ;) But yeah I know how that system works.

[C ///M]

Damn, when those motors go, they sure go..

[BimmerToad]

pretty fat lobes on those cams. Thanks for the pics

[JeffG]

haha, that reminds me of a M3 i got at work.

repair order reads: "owner states they were shifting from 1st-2nd, heard a terrible noise and the vehicle instantly lost power and shut off. will not restart. advise."

thing had no compression, there was a nice hole punched into the top of the valve cover over the exhaust cam sprocket as the chain jumped off. the exhaust cam stopped spinning correctly and it was over with.

submitted a report to technical, within minutes they told me to overnight the DME to them before continuing on anything else, obviously to check the last few moments of running data prior to the failure. sent me word back the next day to put a new motor in there as it wasn't the owners fault.

warranty pay :(

[equate975]

Meh a little bondo and she will be fine :)

Man thats nasty

[SA E30]

Wikkid... I wish there was a course like this here in South Africa.

[Jarvis]

Wikkid... I wish there was a course like this here in South Africa.

I got the S54 by luck. The 19 guys in my class were split into 6 groups and given different motors to tear down. Most got old M20s and M30s that have been taken apart and put back together by previous students a few times. I found the S54 in crate that had arrived only days earlier while we were on spring break. My professor didn't even know what was in the new crates. I had to choose between an M54B25 that welded itself together, or that S54. Easy decision :D