gnx7

iTrader: (28)

They say the magical number is about 1000rwhp before the crank becomes a weak link. Well... We made over 1050rwhp/1050rwtq at 14psi on e85 with an ls9 block, stock ls1 crank, Compstar rods (found out what they were finally), coated Wiseco pistons, stock ls7 lifters that we spun to well over 7000rpm many many times (7800 when pushed), MAST ls3 heads.

Did a bunch of 19-22psi passes in 5th gear at the 1/2 mile races which is easily 1200-1300rwhp+ And ultimately did it in. 5th gear with 1200 rwhp is a lot of load.
Luckily no block damage as far as I can tell. Rearmost rod cap heated up and one of the bolts was stuck. Had to use a cut off wheel. Other journals looked primo believe it or not and the bearings checked out clean with no debris traces. It happened in 4th gear well over 140mph at Shift Sector 1/2 mile event on a bye run....and simply shut off. I think the reluctor wheel lost signal with the sensor and the Holley EFi did it's job by cutting fuel/spark/turning it off.

Driving home today I thought about how it failed. I was doing a bye run (opponent blew up) and was showing off by launching on the 2 step and smokin them in 1st/2nd/3rd and then slammed it into 4th and it got traction all of a sudden with high rpm and then it just shut down. I'm guessing the shock load simply snapped it!

Anyone have a forged stock stroke crank they want to sell? Needs to be 6 bolt rear flange.

66Chevellelq4

Showing off on a bye run? Bet that wont happen again haha

one fast zo6

iTrader: (490)

A better crank now means more boost I have never seen a crank break like that.

Rise of the Phoenix

iTrader: (27)

Seems like bad stuff always happens when you try to show off. I'm sure it would have let go at some point anyway.

rkreigh

had a stock turbo buick crank crack like that right in the center main engine would still run. the cast crank flexes and stress fractures and finally lets go. the forged stuff seems to handle the "crank whip" flexing much better. if you find a stock stroke forged crank that's not much over 1k let me know. looking also!!! the 4.0 stroke seems to be the "one the vendors are pushing"

I'd like to even go with a short stroke crank with longer rods to help out with a better rod angle ratio.

Forcefed86

iTrader: (4)

Well that stinks! So the plan is order another crank and put it back together?

Once you hit those power levels, things get expensive in a hurry! Seems like big block stuff is the way to go if you want the biggest bang for your $ above 1200ish hp.


...and where's the video!?

oscs

iTrader: (19)

I think Tick will be your best bet for a forged stock stroke crank. Everyone else is back ordered and no one keep them in stock. On a side note.. That sucks! seeing **** like this makes me want ERL block so bad so i can just take it to the next level. Also 1050whp at 15psi is crazy.. How are you able to achieve such numbers with a stock stroke 6.0 block?

mkvamso

iTrader: (2)

Those mast heads move a **** ton of air
That coupled with a good cam, e85, and a decent amount of timing itll make big power.

364 with awesome heads/cam have made 500 wheel plenty of times
Double the atmosphere should be right at double the power

allmotor1

Almost seems unnatural somtimes. I knew a guy did tons of passes in his car. One day at a meet decides to do burnouts etc and boom. Its crazy.

gnx7

iTrader: (28)

I'm hoping the block is salvageable.... the rest of the engine looks good. The valves didn't kiss the pistons..... all the other journals look great.

No video to show.... I ended up beating a $250K+ Heffner built TTGallardo that had been converted to rwd (e-gear trans) to compete in my class at the same event and won my class. Both of us suffer from traction down low... I made boost quicker and stayed ahead of him the entire time.

Note to self.... keep it under 1000rwhp on a stock crankshaft. My buddy built the motor and it had a GTS76 on it before.... he never planned to make this much power.... until a PT8847 (t4) with billet wheel was made to fit in the engine bay.

At least it didn't destroy the block, then put oil under my rear tires or catch on fire going rather fast.

It's a stock 4.065" bore... and stock LS3 intake/90mm TB running a baby LG Motorsports Executive cam. I'm guessing it would make around 500rwhp all motor.

some other vids:


Did 9.35@163mph a couple passes later. 275/50/15 M/T ET Street drag radial

oscs

iTrader: (19)

What compression are you running? I misread the LS9 i thought it read LQ9

SPRAYED 01

iTrader: (22)

I have to say all the t4 turbo cars that really surprise me are running some version of a pt88. I may have to just get that turbo and call it a day. Mightymouse is another that was running about 160mph in the quarter with a pt88.

Granted my cam and intercooler are not ideal and weight (3850lbs) but my car is like a 140mph car with a t4 comp 92mm turbine and 88mm billet compressor. I mean 20mph difference, thats nuts.

Anyway, congrats on the sweet carnage. I would be proud of that and hang it on a wall.

SPRAYED 01

iTrader: (22)

Thats like an 84mm turbine right? If so wtf!!!

LJMSJohn

I have a K1 crank in stock... but it has a 24 tooth reluctor wheel on it.... I have 58 tooth reluctors too.... would cost a little bit extra to have them swapped.... or switch your holley over to 24/1x with a different cam gear.....


But... I do have the crank in stock.

oscs

iTrader: (19)

Do you keep these in stock regularly? I was under the impression that people special order these due to the low demand

LJMSJohn

I do try and keep a couple of the stock stroke K1's in stock.... most guys do want to step up to a 4 inch arm if they are going to the trouble of putting a complete rotator in the motor.... Callies discontinued the compstar level stock stroke cranks due to low demand yes.... but they will still make you a dragonslayer or better unit.

stevieturbo

Nice break ! but any ecu would shutdown the engine when it loses a sensible crank trigger. The crank is the single most important trigger that actually allows an engine to run.

I'm sure it was more a fatigue item that would have failed at some point in time rather than an instantaneous event being the sole cause.

IronBlocked

HP doesn't snap crank as badly as tq does, and that poor 10 year old crank was seeing a lotta torque

gnx7

iTrader: (28)

It's 10:1 compression. Runs a Treadstone 4" thick side to side pass $400 intercooler. Only runs e85 which where we are varies from 82-85% year round. Upon tear down no gooey crap on the injectors or intake/heads. It does run a vacuum pump and that keeps all the oil out of the intake. It's amazing how much moisture and oil vapor the catch can really traps with it.

Dropped off block and parts to my machinist today. Find out next week the parts tally.

oscs

iTrader: (19)

Well that explains the high HP number with such low boost. Id love to see your timing curve.