Roush Engine Failure – Pictures

[RodKnock]

Darren, the OP, said this wasn't a "Bash Roush" thread. So, let's not get distracted and derail the thread guys.

[dcdoug]

Originally Posted by RodKnock

let's not get distracted and derail the thread guys.

Now that's funny right there - .

[Excaliber]

Good on the OP not wanting to bash anybody. That leaves it up to me then!

How do I quantify that Roush's work is defective? Simple, the rocker arm shaft nut backed off, which resulted in a broken shaft. Now either the owner loosened it up or we believe him when he says he's never opened the motor. There is no history, that I know off, where FE rocker shaft nuts/bolts back off on their own WITHIN 2,000 miles of being installed. It just doesn't happen, that nut was not tight from the factory is the only reasonable explanation. PLUS, it was noted several other nuts/bolts were loose as well. This is very strong evidence of defective workmanship.

I'm sure open to other plausible reasons for such an occurance. I totally understand now wanting to bash anybody, dealers do take a beating, often undeserved. That does not appear to be the case here, from what we have heard (without cross examination) Roush is looking very guilty on this one. Not a bash, just the facts.

HTOB's are to risky for my taste, I don't care who makes it or put's it in, when it fails (and all to often they do) it's a nightmare of a repair job. Don't need the risk or the hassle.

[madmaxx]

There is never an excuse for a fastener to loosen. Fastener technology has been around for 1000's of years, LOL!!! Never had a fastener loosen on my Envoy, Lexus, gmc truck, bonnevilles, cadillacs, triumph spitfire, miata's, oldmobiles, mercruisers, mercury's cheverolets, I would guestimate 40 cars and 3 boats. I did have the carburator come loose on my sears crafstman blower one time, so I guess it is possilbe. It was covered under warranty.

Loctite is only one solution, there are different types of nuts etc.

Do we really know if a fastener loosened in this instance? The nut came off so did we find the nut? Not familiar with this valve train set up is the culprit set to a predetermined torque value or is it adjusted with backlash? I doubt something was left loose, wonder it something else is not going on, excessive deflection, vibration, thermal cycling etc.

[209]

Roush should repair it! I'm looking at a GT40 someday and Keith will have my business. And I'm not the only one. Bashing? Phooey! 209

[N2VENOM]

The nut was found off the stud when I removed the valve cover. The nut came OFF! This is my 10th cobra and I have never had a problem like this. Parts are on the way. Darren

[madmaxx]

So the nut was not on the stud, where was it? Is it in the oil pan? I guess it could not hurt anything, it would never get past the oil pump pick up screen, probably to big to go down the drain holes. I would just make sure it not hanging around somewhere.

I suggest checking the torque on the remaining ones, might want to torque the intake manifold bolts, as far as the rods and crank i would not bother unless you need to remove the oil pan to look for the nut

Originally Posted by N2VENOM

The nut was found off the stud when I removed the valve cover. The nut came OFF! This is my 10th cobra and I have never had a problem like this. Parts are on the way. Darren

[madmaxx]

As far as handling a claim past the warranty period, only one company has ever honored a warranty past the stated warranty. Including TV's, microwaves, engines, lawn mowers, boats, watches, firearms the only company that has gone well above or done anything after the warranty on what I consider a questionable issue on my part is SUPERFORMANCE. They will get additional business from me probably in the form of a GT40. I dearly love my Cobra but it gets HOT in Texas and air conditioning would be nice in the summer.

[Excaliber]

The nut in question is torqued to a specific amount after all valve geometry and clearance issues have been resolved. The intake manifold is already in place and bolted down to specs before the rocker shaft final assembly. The rocker shaft end stand adjustment's, to get the right height, is a crucial step. Once that is determined all rocker shaft support stands are then torqued following a pattern at a specific torque setting. Final valve adjustment can now be set and the rocker arm cover installed (button it up). If it's a "long block" (assembled block, heads and intake package, in the case of an FE) it is now ready to ship. Or, it is now ready for final assembly work, carb, injectors, dyno, etc.

As the rotating assembly would have been balanced previously vibration should not be an issue. Heat cycles should not have an impact on the shaft retainers and mounting assembly fasteners. Excessive spring pressures, due to a "wild cam" should not be a factor (providing proper torque specs were followed). All these things are taken into consideration by the rocker shaft assembly design. Of course some designs are better, stronger than others, but not generally the SHAFT itself, that is fairly "generic" to most FE's (and relatively inexpensive). If a shaft mounting fastener comes loose, for what ever reason, the shaft WILL break in a hurry. It is under a great amount of pressure, and has been carefully designed to handle it.

Re-torquing of these shaft components, while perhaps a good idea, is not called for. Checking for valve adjustment would be logical at about the 2,000 mile mark, some check it earlier, some later. In any case, there should be no valve adjustment actually needed beyond a few thousands of an inch. If the valves are out of adjustment very much beyond that, you have a serious problem. Like a broken rocker shaft or a receeding valve seat, loose fasteners, a bent push rod, a broken or worn rocker or numerous other causes.

I've never personally used something like "LocTite" on the rocker arm shaft nuts/bolts, perhaps it's OK if you do? Maybe I've just been lucky? I wouldn't say it's standard procedure as there is generally no problem with these nuts/bolts loosening up over time (especially at 2,000 miles). Rocker arm shaft re-torque is not a standard procedure, a good idea perhaps, but generally not required or noted as necessary in warranty paper work.

I am NOT a professional engine builder, just an above average "back yard" wrench I guess. I have not worked on a ton of FE's, so I'm not an expert. But I do know what is entailed here, what needs to be done, what should have been done. Based on that, in my opinion, it's defective workmanship on assembly.

Barry R., Kieth, Brent and many others could perhaps offer a better explanation or speculate more accurately on the cause(s) of this "loose nut". Most troubling here is the fact that other loose nuts were found as well. Maybe the motor was built on Friday, final assembly minutes before punch out time?

You may not actually SEE a broken rocker shaft on an FE, by the way. The engine, following a valve adjustment, may run well! You could go for many many miles before you figure out you have a problem. Often there will be no additonal damage to any other components. No metal debris through the engine, nothing that "stands out" and makes you look twice. It is interesting that in THIS case it was a sudden and pronounced failure that led the owner to conclude, "Wow, something just blew."

[N2VENOM]

After reading this thread, how many of you are checking your fasteners?

[Excaliber]

...I'm pulling my valve covers tommorow!!!!

[rodneym]

Originally Posted by Excaliber

...I'm pulling my valve covers tommorow!!!!

Sounds like a great idea!

[undy]

I totally agree with Ernie...

If the nuts were torqued correctly they WOULD NOT have backed off. Although not a professional engine builder, I do have a degree in Automotive technologies and have accomplished a life time in wrenching on my stuff ... and others too.

To me, Roush ranks up there with World Product crate motors, Summit, Jegs and such...

[madmaxx]

No need to bring Summit and Jegs into the picture, their customer service is exceptional!!! I have never had an issue with either and have bought 1000's of dollars from them. They sell the products they dont make them.

Originally Posted by undy

I totally agree with Ernie...

If the nuts were torqued correctly they WOULD NOT have backed off. Although not a professional engine builder, I do have a degree in Automotive technologies and have accomplished a life time in wrenching on my stuff ... and others too.

To me, Roush ranks up there with World Product crate motors, Summit, Jegs and such...

[Keithc8]

They do not know how to build FE engines and that choice of rocker arm assembly shows it. They have several problems with their over priced under powered FE engines. Even they found out there is more to an FE than most realize. Hope you get your engine fixed and if it cost over 20,000.00 they are sticking it to people.
These dealers want you to buy the Roush engine because they get about a 2000.00 to 3000.00 kick back on them. This is one reason I have not been able to do much business with some of these dealers because they want a lot of money packed on top for them. That is just the way it is and the way they all set it up. Good luck but they are having there problems to.

Let me know if I can help you in any way.

Keith Craft

[patrickt]

Originally Posted by Keithc8

They do not know how to build FE engines and that choice of rocker arm assembly shows it. They have several problems with their over priced under powered FE engines. Even they found out there is more to an FE than most realize. Hope you get your engine fixed and if it cost over 20,000.00 they are sticking it to people.
These dealers want you to buy the Roush engine because they get about a 2000.00 to 3000.00 kick back on them. This is one reason I have not been able to do much business with some of these dealers because they want a lot of money packed on top for them. That is just the way it is and the way they all set it up. Good luck but they are having there problems to.

Let me know if I can help you in any way.

Keith Craft

And reading between the lines of Keith's crystal-clear post, I interpret it to say "and no, if you have a properly installed hydraulic lifter valve train on your FE, there is no reason to have to pull your valve covers off and retorque the damn thing."

[undy]

Ohhhhhh... off the turn-buckle, KC 1, Roush 0.

[RodKnock]

Originally Posted by patrickt

And reading between the lines of Keith's crystal-clear post, I interpret it to say "and no, if you have a properly installed hydraulic lifter valve train on your FE, there is no reason to have to pull your valve covers off and retorque the damn thing."

A. I don't think it says that.

B. As a precationary measure I think it's prudent.

[dcdoug]

Originally Posted by patrickt

And reading between the lines of Keith's crystal-clear post, I interpret it to say "and no, if you have a properly installed hydraulic lifter valve train on your FE, there is no reason to have to pull your valve covers off and retorque the damn thing."

Like a dog with a bone.....

[patrickt]

Originally Posted by dcdoug

Like a dog with a bone.....

Got me where I am today....