I have the motor in the sig. I spin it to about 6500 RPM. I want to add h-beams and je pistons but I was wondering for a 400 Rwhp car with a 200 shot on top of that would the stock crank be enough to hold up? Or should I bite the bullet and get an aftermarket crank? The tech I work with was spraying a 300 shot on a stocker for 3 years without problems on a studded two bolt main with the same rods and pistons I want to use. However his was a race only car and not a daily driver. Thanks.

 

150 shot safely

 

i was spraying a 175 to a stock longblock. there are guys spraying 150-200 on heads/cam stock bottom end cars.
just make sure the fuel/ignition systems are up to snuff.

Tune Up means everything

 

Dirk is right about the tuneup being on. FWIW, I drive mine on the street regularly and spray 200rwhp on top of my heads cam combo. I figure I am at around 600rwhp with a 200 shot and run the times in the sig. I have a stock crank and 2 bolt main block, JE nitrous pistons, and eagle h-beams.

Matt

 

thats all fine and dandy. i am a machine shop owner and knew i should not put in my 2 cents. but i do love ya guys for trying to prove me wrong no hard feelings and if ya ever need anything ie(engine rebuild) give me a call ok

 

noone tried to prove you wrong,dont get upset. the stock crank has proven to be quite durable. many guys have gone bottom 10's high 9's with stock cranks and good supporting parts.


thanks for the offer on a rebuild,but im building my own right now

 

I'll get back to you all next spring...LOL Ross Nitrous pistons, 6" Manley H-Beams, Stock crank, 2 bolt main, GM 847, ported heads...and a 200 shot

Frank

 

i am not upset. where these stock bottom end cars in the 9's? i dont run a stock crank, taner dont, lets check the list


Taner Bosnali
1996 Camaro SS- Fastest 4th gen LT1 6-speed
399ci LT1, AFR 227cc heads, Nitrous, T-56
¼ mile time: 9.44 @ 146.18
60 foot: 1.355


not stock!

Rob Cowling “Yellow Z28”
Camaro Z28
383 LT1, AFR 227cc heads, YS trim (now YSi trim), TH400, 712rwhp at 19.5psi
¼ mile time: 9.52 at 142
1/8 mile time: 5.98 at 116 (around a 9.20 at 147-149 in the ¼)
60 ft.: 1.30

not this one either!

Ralph Olivarez/Madman,(car formerly owned by Dallas Castro)
1994 Camaro Z28
355 LT1, LT4 heads, TH400 w/brake, ProCharger D-1, FAST system, Madman suspension
1/4 mile time: 9.56 @ 141mph


no stock crank here!

Jason Warren
1995 Camaro Z28
350ci LT1, Ported LT4 casting heads, w/ 300 shot of nitrous
¼ mile time: 9.58 at 140
60ft.:1.28

not him either!

Darren Nichols "Chevyguy3”
1995 Pontiac Formula 396, cam 254/259, .664/.656, 112LSA , "Stage 3" LT4 heads 2.00/1.60 valves, 279cfm , TH400, w/ 200hp shot nitrous
¼ mile time: 9.63 at 142

nope dont look good for the stock crank guys!

Steve Quinn
1995 Camaro Z28, 370ci LT1, Ported factory LT1 casting heads, Naturally Aspirated, w/ race wt @ 3052
¼ mile time: 9.713@138.16
1/8 mile time: 6.277 at 108.3
60ft: 1.271

oh where can they be?

Daren Wlodarczyk
1996 Trans Am WS6 Convertible
398ci LT1, AFR 227cc heads, 300shot of nitrous, 811rwhp and 928rwtq
1/4 mile time:9.763@138.49
60ft: 1.372

not him either!

Jim Moran "INTMD8"
1997 Camaro SS
357ci LT1, 9.2-1 comp. AFR 195cc heads, 218/218 cam, Twin GT61's, T56, 847rwhp 847rwtq,, raceweight at 3,740lbs.
1/4 mile time: 9.809 @149 mph

no stocker in this one!

Jeff Stevens
1996 Camaro Z28, 383ci LT1, Vortech YS trim
¼ mile time: 9.82 at 145.03
1/8 mile time: 6.34 at 112.05

did stock lt1's come as 383's?

"BigkevC5"(car now owned by East Coast Supercharging)
1997 Camaro Z28-Stock Bottom End record holder
350ci LT1 w/ LT1 ported heads, Cam, boltons, 150 shot
1/4 mile time: 9.85 at 135.5

wait here is one maybe we should ask him how long it lasted!

Jordon Musser
1994 Camaro Z28
401ci LT1, AFR 210cc heads, T-56, Solid roller cam, 225shot
1/8 mile time: 6.43 at 112(about a 9.9X at 140)

not him!

Richard Krause "rskrause"
1995 Camaro Z-28
383ci LT1, Procharger, nitrous, full emissions equipment, with "road race" type suspension
1/4 mile time: 10.06 at 141.15
1/8 mile time 6.55 at 110.52
60 foot: 1.55

nope!

Dave Odehnal
1993 Camaro Z28
Ported factory LT1 casting heads and intake.
1/4 mile time:10.15 at 134mph-Naturally Aspirated
60 foot: 1.37

nope!

Matt "Nostang 96z"
1996 Camaro Z28
355 LT1 11.5-1, stock crank, 2 bolt main,GTP S2 LT4's, GTP-6 cam, 200 shot of nitrous, th400, raceweight at 3650lbs
1/4 mile time: 10.27@133.24 1/4
1/8 mile time: 6.595@107
60 foot time: 1.592

oh wait a minute thats 2 for you!

i never said it cant be done i said safely please post these other guys name's so we can add them to the list

 

i dont know frank i dont know if that 847 will be enough cam to run high 9's mid 10's my guess would be low to mid 11's

 

The only stock crank failures I have ever heard of have been the crank nose, due to running a blower. In fact, mine was damaged upon engine teardown. I just grinded and polished it smooth. Have never heard of a any catastrophic failures. The stock crank is nodular iron, much stronger than typical cast iron, but obviously not as strong as the bullit proof 4340 crankshaft.

IMO if you have the money, it is worth buying a forged crank.

 

i was under the impression Jason warren has gone 9's with the stock crank,but sorry,i dont obsess over stock crank guys,please continue your rant,i'll stay out of this.also,i said stock crank,not bottom end.
FWIW<Darren went 10.2's with a stock bottom end and a 200 hit.
sorry,i didnt realize how sensitive some people on here are,enjoy.


Just a 11.0 stock longblock,but i dont know anything

 

This is the kind of question that doesn't have a yes-or-no answer. If you drastically overstress a part, you can have an immediate catastrophic failure by exceeding the ultimate strength of the material. But most metal parts fail due to fatigue. Fatigue is a process by which a component is weakened by repeated bending or other cyclic stress, often to the point of fracture. The stress can be below the ultimate tensile stress, or even the yield stress of the material. However, over a large number of cycles the effect can be catastrophic. The failure process starts with a microscopic crack which widens with each subsequent cycle.

This kind of failure is probabilistic. The number of cycles required for failure varies between "identical" parts and is not predcatable for any given part. But it can be analyzed and predicted for a large sample of parts. In all cases, the greater the stress, the shorter the life as the damage is cumulative. Fatigue life is influenced by a variety of factors, such as temperature and surface finish, in complicated ways. Some materials, for example steel and titanium, exhibit a fatigue limit, a limit below which repeated stress has no effect. Most others, for example aluminium, exhibit no such limit and even infinitesimally small stresses will eventually cause failure.

As applied the question at hand, on average, a cast crank will simply not have the longevity of a stronger forged part. The loads we are talking about here will not cause immediate, catastrophic failure unless the part was already fatigued to a great degree. Unfortunately, the data does not exist to allow a prediction of how long a given crank will last. Infernos question therefore cannot be answered except to say the following:

1. A stock crank is unlikely to fail catastrophically the first time you spray it with a 200 shot.
2. A forged crank os very likely to last a lot longer than a stock crank if you repeatedly spray it with a 200 shot.
3. It is impossible to quantify the likely time to failure with the data we have available.
4. Crank failures are relatively rare.

Rich

 

Matt's been 11.4 on the motor with a GTP-6 cam, which is almost identical to the 847. My new engine had BETTER run mid 11's on the motor I'm looking for low 10's on a 200 shot. Hell, I'm already running 12.0 with a stock 96,000 mile bottom end with a tiny CC305

Frank

 

BTW, Jason Warren was running 9.5's with a stock crank, 2 bolt main, and a 300 shot.

Frank

 

What these examples leave out is "for how long?"

Rich