Read this and tell us your professional opinion.
http://www.stangsunleashed.com/forums/index.php?showtopic=779
Any merit?
http://www.stangsunleashed.com/forums/index.php?showtopic=779
Any merit?
Fourcam, check out this thread about the 5.4
- Thread starter Purvis
- Start date
Sounds like the CRANK is the weak link...not the rods 
This is pretty huge though. Not good news at all.
There is another thread on those forums that said there is rumored to be a delay in production (rumor) because of the cranks until maybe Jan. 07
This is pretty huge though. Not good news at all.
There is another thread on those forums that said there is rumored to be a delay in production (rumor) because of the cranks until maybe Jan. 07
i wouldnt say its the weak link, i would say its a huge issue. evidentally they are just breaking off at the snout due to SC load and a 26lb DAMPER!!!! damn. this is something that MUST be fixed before release, there is no "just the weak link" about it.
http://www.stangsunleashed.com/index.php?categoryid=18&p2_articleid=94
(^^^full story^^^)
http://www.stangsunleashed.com/index.php?categoryid=18&p2_articleid=94
(^^^full story^^^)
As far as the first link is concerned, I believe RobertLane stated that the GT500 was using 4340 forged Manley H beams, which is incorrect. We already know they're from Mahle and not as good.
Regarding the crank issue... Is it possible that due to the huge load on the front of the crank from the blower/26lb damper, that the forged cranks are actually snapping? Yes. I received some info on this issue around a month ago though I wasn't sure what was actually causing the problem at that time.
You can also see this kind of problem with forged 4.6 cranks in cog driven supercharged applications. Simply too much load on the snout of the crank.
My best guess as to how to resolve the issue (going by what's in front of me) is by using a large diameter ATI dampner (~$400) which would definitely reduce weight on the snout but dampen harmonics just as well or better than the stock piece.
Forged 5.4 cranks are stout pieces, essentially mimicing forged 4.6 cranks, save the lack of a center counterweight (which doesn't really come into play harmonically speaking until over 7500rpm). Stock forged 5.4 cranks have been tested to 7500rpm/1400HP before showing signs of flex.
That being said you also have to remember the Ford GT crank issue (same crank). The oil leak that required a speed sleeve to fix (TSB) was due to a random worker who incorrectly polished the cranks with an emory cloth--instead of keeping his hand in the same place while the crank revolved, he moved it down the length in effect creating a path for the oil to follow out of the engine.
Regarding the crank issue... Is it possible that due to the huge load on the front of the crank from the blower/26lb damper, that the forged cranks are actually snapping? Yes. I received some info on this issue around a month ago though I wasn't sure what was actually causing the problem at that time.
You can also see this kind of problem with forged 4.6 cranks in cog driven supercharged applications. Simply too much load on the snout of the crank.
My best guess as to how to resolve the issue (going by what's in front of me) is by using a large diameter ATI dampner (~$400) which would definitely reduce weight on the snout but dampen harmonics just as well or better than the stock piece.
Forged 5.4 cranks are stout pieces, essentially mimicing forged 4.6 cranks, save the lack of a center counterweight (which doesn't really come into play harmonically speaking until over 7500rpm). Stock forged 5.4 cranks have been tested to 7500rpm/1400HP before showing signs of flex.
That being said you also have to remember the Ford GT crank issue (same crank). The oil leak that required a speed sleeve to fix (TSB) was due to a random worker who incorrectly polished the cranks with an emory cloth--instead of keeping his hand in the same place while the crank revolved, he moved it down the length in effect creating a path for the oil to follow out of the engine.
Something that puzzles me however is why the Ford GT with higher redline and similar blower/internals hasn't had the same issue if it is indeed using a super heavy dampner as well. My best guess at this time is that it's related to the oiling system (which I haven't seen in detail yet) which is why it's not plaguing the GTs as well.
The dampners on 4.6s are also quite heavy which is once again due to the oiling system and the harmoics it can cause. Ford isn't doing this, adding a large amount of weight on the front of the crank, for nothing.
The dampners on 4.6s are also quite heavy which is once again due to the oiling system and the harmoics it can cause. Ford isn't doing this, adding a large amount of weight on the front of the crank, for nothing.
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Maybe it isn't a GT crank afterall? I consider anything that breaks with stock power and components either pretty weak or poorly designed...one of the two. What is up with a 26lb dampner??! That seems ridiculous. That is the same weight as my Exedy twin disc clutch setup that includes the flywheel!
broeli said:
A forged 5.4 crank is a forged 5.4 crank. They are all the same.
Like I said, the cranks are plenty strong and are very nice overall, they are not the issue. I've seen billet steel rods bend in a 1200HP 4.6 before, are they junk because of it? No, they bent because coolant spilled into the cylinder causing hydralock--otherwise they would have been fine. Same applies here.
God I can't wait to hear all the Chevy loving import sodomists going ape shit over this.
I was having a similar thought, but I included all those that verbally dislike the Shelby.Fourcam330 said:God I can't wait to hear all the Chevy loving import sodomists going ape shit over this.
:idea:
Ah............the beauty of the Internet.............forums, good news, bad news, good atitudes, bad atitudes, etc............
Better to catch the problem now instead of it later on a recall. Many cars have problems, domestic and imports................that's why ALL dealerships have service departments, BMW, Mercedes, Ferrari, and Porche included.
Ah............the beauty of the Internet.............forums, good news, bad news, good atitudes, bad atitudes, etc............
Better to catch the problem now instead of it later on a recall. Many cars have problems, domestic and imports................that's why ALL dealerships have service departments, BMW, Mercedes, Ferrari, and Porche included.
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One last note on forged cranks. IIRC in '04 they stopped nitriding them. No doubt the process makes them "harder" but I don't see it making a difference in this situation; again as the load on the snout necessitated by harmonics (most likely from the oiling system) is the real issue.
R1Lello said:
Exactly. The bottom line is Ford is aware of the issue and will correct it. If you remember back in '01-02 Ford was literally blowing through aluminum 4.6 blocks trying to get the 03/04 Terminator engine right. Something tells me that when the GT500 is released, it won't implode under its own power.
While it wouldn't make sense to make two different forged 5.4 cranks..not all "forged" cranks are created equal. There are different processes such as flat forging and non-twist forging. Then there is always different materials used..anything from a 1045 to a 4340
I have an idea... :idea:
The cranks that go in a Ford GT do not have the flat for the oil pump machined in them, They were using normal Navi/truck cranks during development which had the flat. They were cracking at the snout even though there was no oil pump mounted there.
The oil pumps are still driven off the front of the crank but they are dry sump pumps and belt driven,The GT cranks no longer have the flat machined in the snout.
I would be willing to bet that this is where they are failing... Why now and not on Lightnings???
Maybe the damper weight...
Maybe the heavier rod and piston weights...
Maybe the combination of oil pump load, internal reciprocating weight, heavy damper, and higher blower drive loads(roots)...
If they are running Ford GT heads then they would also be running Ford GT lash adjusters.... yes???
If I remember correctly these adusters supposedly require the heavier oil that only the GT runs... 0W50???
Could that be contributing to the higher oil pump loading???
It would be right on the area know to be prone to torsional stress cracking.
Perhaps a combination of all these things :shrug:
Most unfortunate to say the least!!! :nonono:
The cranks that go in a Ford GT do not have the flat for the oil pump machined in them, They were using normal Navi/truck cranks during development which had the flat. They were cracking at the snout even though there was no oil pump mounted there.
The oil pumps are still driven off the front of the crank but they are dry sump pumps and belt driven,The GT cranks no longer have the flat machined in the snout.
I would be willing to bet that this is where they are failing... Why now and not on Lightnings???
Maybe the damper weight...
Maybe the heavier rod and piston weights...
Maybe the combination of oil pump load, internal reciprocating weight, heavy damper, and higher blower drive loads(roots)...
If they are running Ford GT heads then they would also be running Ford GT lash adjusters.... yes???
If I remember correctly these adusters supposedly require the heavier oil that only the GT runs... 0W50???
Could that be contributing to the higher oil pump loading???
It would be right on the area know to be prone to torsional stress cracking.
Perhaps a combination of all these things :shrug:
Most unfortunate to say the least!!! :nonono:
I still like Four Cams idea...put the ATI dampner on there.
Sorry I am drunk but in my inebriated state I still think that 26 lbs is a hell of alot for a harmonic dampner. C'mon Ford get this straight, I need to see one on the streets...it is killing me,
Sorry I am drunk but in my inebriated state I still think that 26 lbs is a hell of alot for a harmonic dampner. C'mon Ford get this straight, I need to see one on the streets...it is killing me,
broeli said:
The cranks are identical. The only difference is where they're radiused near the snout as Johnny said.
The Ford GT motor broke a couple of cranks (at the snout) during WOT durability testing and it was traced back to a problem with the way the crank snout was machined and how the dampener fit (shot a damper through the roof of the dyno room). The crank snout was machined different and no problems were had after that.
This sounds like the same thing. Could be an old story that had been brought back up out of context, or maybe Ford lost the durability testing results for the GT (seems unlikely, but with HTT in charge of SVT for a while, who know what happened?).
This sounds like the same thing. Could be an old story that had been brought back up out of context, or maybe Ford lost the durability testing results for the GT (seems unlikely, but with HTT in charge of SVT for a while, who know what happened?).
Fourcam330 said:
I believe when all is said and done we will find that the cranks in the GT500 and the 05/06 Ford GT are in fact NOT identicle.
I believe the differences are the following...
A Ford GT has no flat machined in the crank snout for the normal oil pump drive.
In addition to the absence of the drive flat,
at the first "step" there is a "fillet" added to enhance the snout's strength.
On the GT500 crank the flat would have to be there... since we know they are not doing a dry sump oiling system on them.
If the "fillet" is added to the GT500 cranks.. who knows???
Other than that yes I would say they are the same material and most likely the exact same forging, but with slightly different machining than the Ford GT.
Making them possibly identicle to the original parent engines they came from... Forged steel truck cranks.
Jimmysidecarr said:
LOL, sorry Jimmy doing five things at once when I typed Johnny. As far as my comment, I was referring to the forging itself--broeli questioned if the materials used were different. While GT cranks have different machining at the end, the cores are the same, as are the methods of hardening, therefore they have same strength as far as power production/rpm limits are concerned.
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