Crankshaft snout snapped

[Roh92cp]

I'm going back to stock damper this week. Talked with Dustin Whipple and he said there is no reason to have ATI on unless you need overdrive or 10 Rib setup, and I need neither. He said they're made .002 smaller and won't go on all the way usually without a light hone.

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[Hayburner]

I’ve decided to avoid the 10 rib kit and stay 6 rib with my griptech 3.25, id rather break a couple belts now and then than a crank snout Lol.

 

[stang17]

Come to think of it, I had that ATI put on several months after I got the car back in 2016 and I've put on about 4,000 miles per year since then. About 600 miles ago I had the WOT box installed and have almost a dozen passes leaving off the 2 step set to 3500 rpm. I don't get on the 2 step until after the bulbs start dropping, but maybe the 2 step is too violent with a PD blower and ultimately caused the failure.

For those of you that had crankshafts snap, was a 2 step ever used?

 

[BlackandBlue]

I have noticed on this thread that most of the talk as been about figment of the balancer on the crankshaft snout. Very few have talked about the key way fitment.

The key is what transfers the forces to the balancer. No interference fit is going to hold the crank for even a second without a key. That being said if the keyway has any movement what so ever it will start transferring harmonics across the mating surfaces.

A shaving of metal is all it would take to set the key in a position to improperly transmit torque. All of the pictures I have seen have a crack leading to the keyway though the crank. Post #83, #163. The keyway also looks to be distorted.

In my opionion I would look where the toque is being transferred. Even a keyway or key being out of parallel a thousands or two could cause these problems.

 

[pacebria]

has anyone come up with a crank support bracket for the guys using centri blowers?

 

[Crackerjack17]

Why do they even do a keyway? Why not a machined fit, like an axle?

 

[BlackandBlue]

Why do they even do a keyway? Why not a machined fit, like an axle?

Because it is easier to get 1 point to line up with no play then 31 or any other number.

Key ways are extremely reliable way of transferring torque. For the cost you can’t beat them.

Some of these breaks could be bad installation. Some could be bad luck. You could build 50 engines in the same spec range and none of them would have exactly the same harmonics on the crankshaft. At 460 this is not a problems but at 700 the few on the noisy end will have problems. Resonate frequencies can amplify load by a large amount. This puts extra stress on the keyway that would normally be there. Manufacturing flaws also come into foucus at these power levels. Ford put a lot of money into the new gt500 damper and for good reason.

I really feel for the guy that have had this happen to them. This problem alone is why I haven’t ponied up for some extra air.

 

[Jay-rod427]

You could never affodably get splines tight enough to not be sloppy which would defeat the purpose.

 

[Barrel]

Welp... Went with TKM out of North Carolina for a new shortblock. Gen 2 Darton sleeved, Mod2k pistons, Manley I beams, water jacket supports, O-ringed, and a importantly a double keyway.

This beach better hold together this time lol. Gonna throw some more boost at it and we'll see.

 

[stang17]

I ended up getting a pretty decent deal on a brand new 11:1 aluminator, which is set to ship 7/22. I also went ahead and ordered a stage 3 transmission from Ben Calimer which shipped yesterday. If all goes well, I just may be back on the road before the end of the month.

I'm having the ATI rebuilt for $75 and will end up selling it once I get it back.

I don't plan on exceeding 800-850 whp, thus why I decided to go with the tried and true aluminator.

With shipping, everything came to $14,500 for motor and trans. My old motor and MT-82 will be going up for sale in the forthcoming weeks.

 

[Jbud]

What was the cost of the stage 3?

 

[stang17]

What was the cost of the stage 3?

$3,950 if you don't provide a core....rated for 1000 hp and 900 ft lbs

 

[olaosunt]

Come to think of it, I had that ATI put on several months after I got the car back in 2016 and I've put on about 4,000 miles per year since then. About 600 miles ago I had the WOT box installed and have almost a dozen passes leaving off the 2 step set to 3500 rpm. I don't get on the 2 step until after the bulbs start dropping, but maybe the 2 step is too violent with a PD blower and ultimately caused the failure.

For those of you that had crankshafts snap, was a 2 step ever used?

I had a 2 - step on my Hellion car .

 

[Jbud]

I had a 2 - step on my Hellion car .

You snapped the crank snout on a turbo car? That i hadnt heard. Geez now im worrying about the winter build for big numbers. Maybe keeping semi sane numbers is the better long term idea....

 

[fuelforfire87]

So recently stumbled across this thread. I recently had my motor built and had a stock size ATI damper installed because i thought it was better than the stock balancer. I am running a procharger stage 2 D1SC. So would i assume it would be better to switch back to the stock balancer with the procharger pulley that piggybacks on top of the stock balancer. Car has not been tuned yet so no WOT pulls. Still putting break in miles on the motor. Also the built motor is an MMR 1000 so i'm not planning to make more than 850-900 whp. @ProChargerTECH what do you think?

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