FreakSHO's Wicked Two-piece Crank Mod!

['94SHO]

3800??

Well, I beg to differ... As the previous owner of a Monte Carlo SS/SC, and the
owner of several 3800 powered vehicles, I respectfully disagree.....
These engines are almost bullet proof, but they are NOT idiot proof....
They are a comepletely different driving experience from the SHO.. I prefer the SHO... But, there is something to be said for climbing a steep hill, in OD,
at 1200 rpm. I used to get 30+ mpg at 75 mph with the cruise on.
Yes, they redline around 5K, and are not nearly as sexy as the SHO at WOOT!
We had a snowfall of 15 in. in Maryland not to long ago, me and my wife jumped in the Monte, and drove to work. Only to find that all the roads were closed, due to a snow emergency.. But, I must say, I DO know of a local owner of a 3800 who has blown 2 engines in one year.. Maybe a run of bad
cranks? My mother had a '92 Bonneville, with 242,000 miles on it. She never
even CHECKED the oil, much less changed it..(that was my job).
It would STILL go over 120 mph, and got over 20 mpg.. Go figure..

 

[SHO92]

There were a few snapped cranks a few years ago. It was thought to be because of a 1 piece crank pulleys. I think that's why Marcel asked.

 

[BaySHO Performance]

Details on this process?

See http://www.key-to-steel.com/Articles/Art132.htm for a detailed explanation of the gas nitriding process. Part to be treated gets heated to around 600 deg and exposed to ammonia vs Cryogenic treatment where the part gets cooled to a veryilow temperature, usually using liquid nitrogen.

 

[BaySHO Performance]

There were a few snapped cranks a few years ago. It was thought to be because of a 1 piece crank pulleys. I think that's why Marcel asked.

Yes, boosted SHOs and a crank UDP did not go well together as Gugliardo found out: not enough harmonic dampening. The crank UDP is fine on an n/a car, though.

 

[CosmoSHO]

See http://www.key-to-steel.com/Articles/Art132.htm for a detailed explanation of the gas nitriding process. Part to be treated gets heated to around 600 deg and exposed to ammonia vs Cryogenic treatment where the part gets cooled to a veryilow temperature, usually using liquid nitrogen.

Thanks for that.

 

[SHO Dude]

My question would be, had the crank been machined in any way?

I've seen this several times and it has always happened on a machined crank. I read somewhere that these cranks are roll hardened. the outer layer of material is incredibly dense and hard, but is only a few thous thick. Once you turn the crank and change the fillet radius, the crank is doomed.

This is a picture of our wall of shame.



It showcases some of the crazy crap we've seen over the years. In this picture towards the bottom right, you can see a 2-piece crank that looks just like yours. It was also a machined crank that was in one of our early 3.2L MTX cars. So now, we only use ****** cranks for engine builds. There is no way to economically get the strength back in the unit.

 

[CosmoSHO]

My question would be, had the crank been machined in any way?

Yes, this crank has std mains, but the rod journals were 0.50mm under. The fracture was in the material between #1 and #4 rod journals.

 

[AREA 91]

Awesome Mod! I better fly down and help you with the SHO.
How's the family?

 

[sho_sc]

My question would be, had the crank been machined in any way?

I've seen this several times and it has always happened on a machined crank. I read somewhere that these cranks are roll hardened. the outer layer of material is incredibly dense and hard, but is only a few thous thick. Once you turn the crank and change the fillet radius, the crank is doomed.

Doug, a couple years ago when I had my mishap with a SC oil return line blowing off, I had left instructions with the machine shop NOT to turn down the main journals. As a matter of fact, only 1 rod journal that need turning down more than 10 under and 2 others that needed turning at all. However, when I pickup the “semi-assembled” short block, they had turned EVERY journal 20 under. While, they did bearing match all the journals using the closest tolerance, I was very leery. The machine shop owner assured me that everything was going to be o.k. That engine, so far, has 20K miles on it and has seen 19-20 psi of boost many times. Could be luck…....for a change.

 

[TRicker]

you call that a crank? man...... i thought these yamaha engines were crazy. my 2.5L duratec crank didnt even get dinged when half of a piston got wedged between the block and the crank. you call that forged? wtf!

 

[CosmoSHO]

Awesome Mod! I better fly down and help you with the SHO.
How's the family?

Come on down!:woohoo:

 

[Toolman]

That's where they all go, mine and Tom Guagliardo's included. It's a weak point on the crank.

Have the replacement gas nitrided. Cryogenic treatment is not worth the cost for raw carbon steel.

Nick! Long time no see!

TT

 

[Toolman]

you call that a crank? man...... i thought these yamaha engines were crazy. my 2.5L duratec crank making all of 150hp didnt even get dinged when half of a piston got wedged between the block and the crank. you call that forged? wtf!

There you go.

 

[SHO Dude]

it's only a problem when the crank is turned. When my 3.2l went sho-boom, there was half a rod wedged between two counterweights but the crank itself was still fine. When I drove the piece of rod out it spun on the journal just fine. The crank itselfwas just fine.

 

[TRicker]

There you go.

sorry dude but my 2.5L svt motor was running a 100 shot and made 318WHP and made 189 WHP N/A.

that's more than some people can say on the dyno thread on this forum.

my 3L swap will make 225ish and 400+ with boost. and i won't be breaking the crank in half any day soon!

edit: and let me add that the car (when the piston shattered) went from 6800 rpm to 0 in an instant. the piece of piston dead stopped the engine from almost redline instantly and it didnt hurt the crank a bit. i'm not tryin to get off topic, i was makin a joke, just like toolman here but seriously, people trash SVT contours and call them "mini SHO's" when they are really totally different and just as fast as most SHO's with similar mods.

 

[Toolman]

sorry dude but my 2.5L svt motor was running a 100 shot and made 318WHP and made 189 WHP N/A.

that's more than some people can say on the dyno thread on this forum.

my 3L swap will make 225ish and 400+ with boost. and i won't be breaking the crank in half any day soon!

It's cool. No SHO crank has ever broken from too much TQ.

people trash SVT contours and call them "mini SHO's" when they are really totally different and just as fast as most SHO's with similar mods.

I did not think calling a CSVT a mini-SHO was considered trashing it, but rather a compliment. Hmm, shows what I know. But I agree, CSVT's are cool, I like them. But I have yet to see one handle the TQ that the SHO crank handles. That 2.5 is a great little engine, but I would not put it on par with the Yamaha as far as robustness is concerned.

 

[SinisterSHO]

That 2.5 is a great little engine, but I would not put it on par with the Yamaha as far as robustness is concerned.

How much hp/torque is your turbo SHO making? How much power are Tony and Mike making?

 

[TRicker]

actually there is only one crank that i have heard of breaking on a duratec too. it was a 400hp turbo that had an oil pump go out and the forged pistons kept and the crank broke in half. i guess he drove it home after it happenned too haha.

the yamaha is a nice little engine. they are definately better than a duratec. but in the crank department, i think they are both in the same boat. the 2.5L and 3L are the same on the bottom, and its a nice forged unit. even so, forged stuff can break too!

the duratec crank was apparently tested and passed a test that showed it would withstand 900 ft/lbs of torque. now no duratec has ever made close to that number and a simulation is different than reality but the cranks in the duratecs are untouched on the noble cars that use a 3L duratec twin turboed to the tune of 500-550 WHP

 

[AREA 91]

you call that a crank? man...... i thought these yamaha engines were crazy. my 2.5L duratec crank didnt even get dinged when half of a piston got wedged between the block and the crank. you call that forged? wtf!

FreakSHO has some serious power! And Russ drive's it hard!

 

[SHO Continental]

I've seen that before...


This was Rick's Green SC'ed '94. If anyone was at the 04 or 05 conventions it won best engine at both. Chromed intake and SC tubing. That happened in April '05.