Broken crankshaft

[olaosunt]

Predator crank is made of a stronger steel vs gt/boss crank.

Hmmm . I heard different ....but would be happy if you could confirm .

Predator crank can be used in any 5.2 or 5.0 block. A 5.2 specific rod (.8281 pin bore, smaller than coyote) and 5.2 specific piston (1.155 comp height, shorter than coyote) will need to be used. Be sure to run thick wall wrist pins on boosted setups when going this route.

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I think you can use any after market rod (same big end size ) with that crank , just have to use a piston with the shorter CH
or the CR will be higher with a standard coyote piston .... I think (I am no expert ).

If someone twists my arm enough (and is willing to pay $$) I could be persuaded to sell mine
predator block /5.2 crank /voodoo (Mahle pistons ) with the shorter compression height and Manley H beam with the tapered end for the smaller size pin .
I am not sure any of the aftermarket companies (Mahle -same as stock , JE and Diamond )making the voodoo spec pistons that require the smaller diameter pin have a thick wall option .

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[K4fxd]

In the early days of centrifugal superchargers, before we realized the need for BOVs, cogged belts were responsible for quite a few broken crankshafts.

Must really be a weak crank, there is no way a cogged belt will need to be as tight as a smooth one.

 

[bankyf]

Must really be a weak crank, there is no way a cogged belt will need to be as tight as a smooth one.

They certainly weren't strong cranks on the old 302s, but typically only broke with the cog setups. Had to do with belt slip being a necessary at certain times.

 

[80FoxCoupe]

Hmmm . I heard different ....but would be happy if you could confirm .

.

I think you can use any after market rod (same big end size ) with that crank , just have to use a piston with the shorter CH
or the CR will be higher with a standard coyote piston .... I think (I am no expert ).

If someone twists my arm enough (and is willing to pay $$) I could be persuaded to sell mine
predator block /5.2 crank /voodoo (Mahle pistons ) with the shorter compression height and Manley H beam with the tapered end for the smaller size pin .
I am not sure any of the aftermarket companies (Mahle -same as stock , JE and Diamond )making the voodoo spec pistons that require the smaller diameter pin have a thick wall option .

To run the predator crank, the small pin bore rod must be used with the shorted comp height piston. The reason the pin bore is reduced is because of the shorter comp height....

 

[80FoxCoupe]

Predator crank info

http://www.mustangandfords.com/features/built-ford-fast

 

[80FoxCoupe]

Insider info says Predator crank material is 44MNSIVS6 . This micro alloy is used by other manufacturers in boosted engines.

 

[olaosunt]

To run the predator crank, the small pin bore rod must be used with the shorted comp height piston. The reason the pin bore is reduced is because of the shorter comp height....

Got it !
So what would happen if you used the 5.2 crank with a coyote rod /piston combo (with 1.165 CH ) ?

I know if you did the “reverse” with boss crank and voodoo piston in a 5.2 block you lose displacement /CR and quench .

 

[olaosunt]

Insider info says Predator crank material is 44MNSIVS6 . This micro alloy is used by other manufacturers in boosted engines.

Thanks . I just increased what I would ask for my predator/5.2 crank short block .... if I ever sold it

 

[olaosunt]

I am assuming based on the above that the OEM predator piston also has shorter CH and uses the smaller diameter pin ?

 

[Jackson1320]

My statement is still true as well. You spend $1900 on a factory shortblock, you're getting what you paid for. It's not like it's worth $3000. It's worth $1900.

there is not a $300 difference in parts between the gen2 and gen3 shortblocks. But there’s a $1600 difference if you purchase the shortblock. So somewhere you are not getting what you pay for. The gen2 has cheaper parts but cost a lot more. So I think that the gen3 is dirt cheap compared to having one built or in comparison to all other generations of coyote

 

[olaosunt]

Insider info says Predator crank material is 44MNSIVS6 . This micro alloy is used by other manufacturers in boosted engines.

Also wonder if the voodoo 5.2 crank is made of the same material ?
I know fewer numbers and even fewer boosted or paired with aftermarket dampers but not heard of any broken voodoo cranks ...(not that means there have not been any )

 

[turnswrench]

there is not a $300 difference in parts between the gen2 and gen3 shortblocks. But there’s a $1600 difference if you purchase the shortblock. So somewhere you are not getting what you pay for. The gen2 has cheaper parts but cost a lot more. So I think that the gen3 is dirt cheap compared to having one built or in comparison to all other generations of coyote

Supply and demand sir

 

[80FoxCoupe]

Also wonder if the voodoo 5.2 crank is made of the same material ?
I know fewer numbers and even fewer boosted or paired with aftermarket dampers but not heard of any broken voodoo cranks ...(not that means there have not been any )

Article says material has not been used before...

 

[80FoxCoupe]

@TKM Conbread what kind of voodoo shortblock failures have you been seeing? Any snout failures?

 

[TGGT]

Factory short block, crank support, balancer, stg2 pulley and various gaskets are in route. I almost have the motor out so I can further assess the damage. I’m doing it at work so I kind of have to chip away at it as time permits. I’m hoping to have it back in the road in 4-6 weeks

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