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View Full Version : Cobra crankshaft snout broke - the whole story (entertaining read)



03CobraAV8R
02-07-2009, 08:48 PM
Posted this on SVTPerformance.com a while back - figured I'd post it here for no good reason other than to entertain. It's written using a lot of unnecessarily complex language and big words. It basically turns things that should be very simple into something that sounds extremely complicated. Good stuff!

"Cliffs notes:

Crankshaft snout broke off. All the valves made contact with the pistons. It's a total rebuild (save the block, rods and heads), getting -11cc pistons this time around though, so it should make a little more power. I hope to have it back in a month or so. Injected Engineering is doing the removal/re-install and tune, and Pro-Line is doing the build.

For those who have a few hours to spare, here's a good read for ya.

Everyone's crankshaft snout twists off every once in a while right? Just routine maintenance on the ol' Mustang. Now they don't make this known in the owners manual, but they reccomend everyone snap their crankshaft snout off at least once a year to ensure proper engine operation. It's a vital first step in the engine rebuild/re-invigoration process.

A little over 3 months ago, Brad (Lankhoss) and I were conducting late night acceleration tests at the classified test facility with his vehicle and a certain 680 RWHP black GT500. Anyways, as we were returning to base, traveling up 285 in right eschelon formation, we gained visual contact on a pair of HID's making rather rapid changes in velocity - an indication that he was most likely cocky - and needed to be neutralized, so we decided to engage.

It was an E46 M5, Brad positioned himself alongside the offending vehicle and gave him a couple of blasts, demonstrating to the M5 the explosive acceleration characteristics of the Z06. The M5 attempted to maintain position alongside the Z but failed miserably as a result of his profound power defecit. I was in trail formation watching the engagement - and it was then that I decided that I needed to give the M5 a couple of neutralization blasts as well.

I reached over to my right and grabbed the gear selection lever (leever) and smartly reposition it to gear number 3, while at the same time rapidly depressing the accelerator to bring the engine up into the proper RPM's for the engagement, it was a brilliant rev match down shift followed by explosive acceleration and terrific G forces, the onset of which rendered me temporarily G-LOC'd (G induced loss of conciousness) - by the time I regained my vision, I was in proper position to engage the M5. I reselected gear 3, glanced at the gauges to confirm proper engine operation and then began a WOT pull.

At the very top of 3rd gear I was met with a brief and rather unfavorable high frequency vibration throughout the driveline, shifter and pedal - I should have let out, but I didn't. I grabbed 4th and at that time I heard and felt something that I won't soon forget. It's hard to describe, it was a combination of an extremely loud BANG, and a very violent shock felt through the shifter, seat of the pants, gas pedal and steering wheel. The check engine light illuminated - I thought at that instant my engine had suffered a catastrophic failure of components. I heard what sounded very much like jingle bells under the car for a few seconds - "pistons, that's gotta be pistons and rods" I thought. Then a loud thump and bump in the car and the sound went away, it was finally quiet.

I heroically maneuvered my striken vehicle to the side of the highway, still wondering what in the hell had just happened. I instinctively grabbed my flashlight, popped the hood and began the initial inspection in hopes that I could locate the failed component(s). However, to my surprise, the component that had failed was actually no longer attatched to the vehicle! The area that the crankshaft snout and lower pulley once resided, was now barren, void of anything resembling what should have been there. Only a sliver of the crankshaft was visible potruding from the front of the timing cover. "Well shitters" I thought, "that certainly puts a damper on the fun".

Now I was on the hunt for my runaway crankshaft snout. Backtracking down the side of the highway, an 18 wheeler blew by me and then I was suddenly met with a familiar sound, jingle bells, only this time with my flashlight pointed toward the dividing wall on the opposite side I could see what was making that sound - there it was, my lower pulley was rolling down the other side of the highway, the 18 wheeler had hit it. I run over and rescue it - about that time Brad pulls up behind my car and I hold up the crank pulley "Here it is! My crankshaft snout broke!" I hollered. He looked at it and said "Wow, damn dude, ya know it works better when that stays on your car!"

Then we called the ol' tow truck and the wait began. He arrived a little over an hour later and we began positioning the Cobra for a safe ride up onto the tow truck. Of course, it rarely ever works out, and something is bound to get torn up - in my case he pulled the right side of the front bumper off along with tearing a piece of my core support on the frame (that's why you're not supposed to tow it from there) but I guess he didn't get that memo. Finally get it up on the trailer and Brad and I follow him to Pro-Line in Woodstock, where the engine was built.

The cause of the failure? Well, I had a lower pulley setup that had a hub which bolted to the harmonic balancer - sometime last year, while on vacation at the beach (Brad was there too) I started the car up one morning and heard a rhythmic knocking sound coming from the engine. I popped the hood and saw the lower pulley wobbling a lot. I drove it to a shop, which turned out to be a POS shop stuck behind what appeared to be a small junk yard, run by some little old man with a white beard named Billy.

Billy was a good ol' boy, and assured us he'd have it taken care of in a jiffy. About 3 days later he was finished with it, turned out it was only a few loose bolts that held the hub on. Billy fixed it alright, upon further inspection when I returned to Atlanta I found out he had snapped off 2 of the 3 bolts in the balancer, way to go Billy! I could write another story about the experience Brad & I had with Billy.

Anyways, I don't know how long that thing had been wobbling without making any noise, as I rarely looked at it while the engine was running. I'm thinking that may have fatigued the crankshaft. Even after it was "fixed" it still wobbled a hair. Over time that may have fatigued it enough that it just finally gave out.

Not sure why I wrote a novel about it, I just started writing and decided I'd make it entertaining, a little creative writing, how about that, lol. Maybe I did learn something in all those communication classes in college afterall!"

J-ROCK
02-07-2009, 08:49 PM
long story short the crank is fucked lol

03CobraAV8R
02-07-2009, 08:52 PM
:lmfao: Word.

J-ROCK
02-07-2009, 08:57 PM
:lmfao: Word.

hate to say it but that all made sense to me lol:goodjob:

collins
02-07-2009, 09:36 PM
damn rick, that IS a novel!!! I'll read it when I get home and I'm not on my iPhone lol

RandomGuy
02-08-2009, 01:46 AM
b-rad is the shit

03RCode
02-08-2009, 01:51 AM
Very interesting read actually.

TS240
02-08-2009, 02:28 AM
Nice write up! lol

Just curious how much does it usually cost to have a termi engine rebuilt?

03CobraAV8R
02-08-2009, 06:04 PM
Hah thanks guys.

It was $4,200 for the build and $2,800 for the removal/re-install, fluids, dyno tune.

Basically it needed new valves, valve job, new crank, pistons, kept the stock rods (they're pretty stout, forged from the factory, as is the crank/pistons), new bearings, rod bolts, main bolts, head studs, etc.

Pretty expensive :(

MachNU
02-08-2009, 06:11 PM
Hah thanks guys.

It was $4,200 for the build and $2,800 for the removal/re-install, fluids, dyno tune.

Basically it needed new valves, valve job, new crank, pistons, kept the stock rods (they're pretty stout, forged from the factory, as is the crank/pistons), new bearings, rod bolts, main bolts, head studs, etc.

Pretty expensive :(

dam that isnt bad...hell i just paid $6000 to have my motor rebuilt! :(