turbo crank?

["More Boost"]

are all turbo cranks 229 castings? and if so is this the only way to tell a factory (stock) turbo crank? please,

 

[Turbo1dr]

As long as it has rolled fillets on both the rod and main journals it's a turbo crank. At least that's what I've been told.

 

["More Boost"]

i was talking to my machinist today and he said all cranks (cast) have fillets but most are "cut" fillets and turbo cranks are "rolled" fillets which is what makes them stronger. how can i tell if they are rolled or cut? (does this make sense?)

 

[turbofabricator]

The rolled fillets look like a "gutter" on the edge of the journal. They look like a groove. They are compressed with a roller at time of manufacture.

 

[BARTGN]

Turbo vs Non-Turbo crank

Could someone post a photo of turbo & non-turbo crank side by side ?

 

[turbofabricator]

Try this: Crankshaft Photo Guide

 

["More Boost"]

my crank has 229 on it, is this only on turbo cranks? and 4.1L n/a ?

 

[turbocaddy1982]

fyi : gm stopped making turbo cranks years ago and made it the same part number as a regular v-6 231...:

 

[49-blues]

The 1989 trans am gta also had one- i think with a different number on their turbo v6 cranks-oil holes were also chamfered.

 

[J-B Racing]

I have heard people go 10.80 with a 229 none turbo crank, and not breaking.

 

[1baad6]

The crank isnt really whats weak,its the mains that usally pull out of the block,causing lots of damage to the bottom end,which in turn destroys the crank,thats why if you ever do a rebuild go with billet center caps,you cant go wrong

 

[vacuum 6]

Here are some more pics.

 

[1QWIK6]

i was talking to my machinist today and he said all cranks (cast) have fillets but most are "cut" fillets and turbo cranks are "rolled" fillets which is what makes them stronger. how can i tell if they are rolled or cut? (does this make sense?)

No you cannot tell visually. You need a special machine that I have at work.

Hegenscheidt-MFD - Wheel lathes, Wheelset Diagnosis Systems, Crankshaft machining units

 

[sixgun86gn]

I personally wouldn't worry about a turbo crank.I usually just go get a regular 231 crank from the local rebuilders and go low 11's-high 10's all I want and save about $250. Never had one break.

The rolled fillet thing is overrated.

 

[Razor]

two castings.. 877 and 229

Both castings came rolled and non-rolled

HTH

 

[BlackBandit]

two castings.. 877 and 229

Both castings came rolled and non-rolled

HTH

That's true. Also, it's worth noting the rolled fillet cranks are not stronger than the non-rolled counterparts. They can just take more "cycles" at any given power level. FWIW I personally would rather use a nice std/std NA crank from a 60k grandma regal than a 10/10 rolled fillet crank that's been beat on it's whole life.

 

["More Boost"]

but if the caps are the real problem, what would it hurt to turn the crank? my crank mains may need .020 cut, would this be unacceptable for useing? (crank is still at the shop getting checked, i'm awaiting the news) maybe i should start looking for a new candidate......

 

[A2000RICH]

That's true. Also, it's worth noting the rolled fillet cranks are not stronger than the non-rolled counterparts. They can just take more "cycles" at any given power level. FWIW I personally would rather use a nice std/std NA crank from a 60k grandma regal than a 10/10 rolled fillet crank that's been beat on it's whole life.

doug anderson from groomes engines said that he had been told by the engineers at Gm that tests showed the rolled fillet cranks were three times stronger than the same casting without them---------i don't have too much trouble believing that-------the reason the cranks break is the caps flex under high power especially if there is detonation-------when the caps flex the centerline of the crank curves and there are forces against the crank that it normally doesn't see---------the purpose of the fillet is to prevent stress risers from forming at the junction of the journals and throws-------this is where the stress would be focused----------while i can see where the fillet crank would be much stronger i can also see where an engine that does not allow the crank to flex along its axis would not benefit from the fillets since they don't increase strength along the radial plane..............RC

 

[1QWIK6]

Also, it's worth noting the rolled fillet cranks are not stronger than the non-rolled counterparts. .

That is not true. I deep roll crankshafts for almost all major crank manufacturers. THERE IS A DIFFERENCE BETWEEN ROLLED AND NON ROLLED. It's what I do for a living. I can post Non-Rolled Data on a crank vs. Rolled data. HHHHHHHHHHHHUGE Difference.