Broken Crankshafts? Really?

[Screamer]

All modular motors have no fillet radius on the crank journals or the crank snout area, in regards to a higher possibility of crank failure in a cross plane crank application would be mostly due to a harmonic issue.

The '05 Ford GT 5.4 had a large radius on the snout. The engine had to be short. That meant no cage like the Lightning and '03 Cobra. A prototype slung the damper through the ceiling in the dyno room. It was built with a stock 5.4 truck crank. The production GT crank had a large radius supporting the snout. The radius caused no space issues as the engine was dry sumped with an external oil pump.

The GT 500 still had a radius and rather than the short damper bolt the crank was drilled/ tapped deep almost through the oil hole of the front main journal. It then used a very long damper bolt to hold the damper and sprocket.Never saw a broken snout but did see several twist.

I built over two hundred mod motors and saw one broken crank. It was a supercharged 3V with a cast crank. It had a big Procharger and made 670 rear wheel. After two seasons of NMRA racing the snout broke right at the undercut.

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[sigintel]

Who gives a shit about a 4000.00 crank and another 5000.00 in parts to make it work, yeah I'm sure people are going to jump all over that.

I give a shit. Lol
If you havent broke a crank or motor you aint tryn.
People braking cranks are looking for info and you have some?

Maybe edit your post:

hi guys! Been drinkn and didnt think this post thru. I know some of you may be burnin big money trashing motors and posting about your experiences so that the rest of us can benefit. I have some really good info but cant really share with you pussies breakn motors. Ha!

Those of us breakn shit would certainly appreciate any contacts or info on broke cranks. Ill kiss your ass for info on broke cranks and what peeps are doing as alternatives. We are all jerks, but sometimes pretty cool in letting bs slide while drinkn just cause we all might talk smack sometimes.

If you gots info cool, please share. If not, grab another beer n chill.:cheers:

 

[RGT350]

I spoke to a vendor today about boosting the GT350 and received an interesting response. Not only did he advise against adding any type of power adder he stated that "there have been many broken cranks out there with stock power and just bolt ons tuned"

I have not heard of a single case of this and wanted to see if anyone has.
In fact, in all my days I have never seen a broken crank shaft. I have seen plenty of spun bearings, broken or bent rods, blown head gaskets etc, toasted pistons but never a crank failure.

Thanks

2016 gt350 -P-1 procharger just broke the crank pully off yesterday as a matter of fact
Pully came off with part of the crank still connected

 

[Dominator961]

Here’s mine

 

[Hack]

Here’s mine

That's not a FPC though. Not from a Voodoo.

 

[nastang87xx]

That's not a FPC though. Not from a Voodoo.

I think he was just being facetious lol

 

[Dominator961]

That's not a FPC though. Not from a Voodoo.

Lol. Correct but it is from my 401 SVO small block. It’s a Sonny Bryant crank, point I’m making is even $4500 cranks break.

 

[Captdistraction]

I've broken a cross plane coyote crank naturally aspirated, a road course motor, snapped right behind the crank timing gear (gen2 crank / aluminator NA). Ford Performance blamed the damper, the damper company blamed the crank, some other engineers said it looked to be a timing failure that caused the crank to "climb" its clearance in the front main bearing then snap under a reversal force. ATI damper, ARP bolt. Threw the damper assembly 400 feet away from the car.

Vaporized $11k, but at least I wasn't significantly hurt, it was at the end of a long straight and the car spun. Just a good bump on the brain (helmet to containment seat / roll cage contact).

 

[svttim]

if the cranks failed at any rate, it would be posted here. Ford does not recommend FI on a 350 but will never tell you not to officially. Break what you want, its your car. The 500 does not have the FPC, that is reserved for the 350 only.

 

[eighty6gt]

The current production 350 crank will last x miles from the factory. It will last y miles with a whipple. Fatigue will take its toll, much faster with the blower on there since the crank bending and loading is increased by some magnitude. A "solution" is indeed a custom crank at a price window outside what Ford could afford to incorporate in the 350 crank. It will still break at some point, given the chance.

Street driving, some old cars and coffee codger with a ball cap and sunglasses pooting around at 3000 rpm with the blower idling 99% of the time, I wonder if we'll ever see a legitimate failure.

 

[GrapeApe]

I am aware of one semi local guy in Texas that snapped his crank snout fairly quickly running a F1A procharger upwards of 900hp on his 350.

Mine has been Whippled for 1.5 years and has had roughly 10,000 supercharged miles with no problems YET @800+ rwhp. Mine sees regular third and 4th gear pulls to 8k rpms but nothing Id call abusive driving. Its on Whipples tune with the stoich modified for MS109 fuel

 

[madlag]

I know of two instances of this. One running ridiculous boost, the other stock. Both broke front crank pulley right off. Stuff breaks. I also know of several high mileage FI setups.

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