Found the power limit of short nose crank

Sheck · Postby **Sheck** » Sun Jul 15, 2007 4:03 pm

Hey guys, got my car back from the dyno on friday where it made 175.7hp @wheels on 9psi boost. Went drifting friday and sat nite and i just discovered this morning that the woodruff key in the keyway is being crushed so its got a bit of a wobble now and is essentially dead. Took the bolt out to find pieces of metal sitting in a bit of dirt/rust. I've tightened it all back up so hopefully it'll get me back to my parents place this friday.

New motor should hopefully be going in this weekend if all goes well

Plus side is that the car felt great while it lasted, full boost by 3.5krpm thats with an R32 turbo. Great to have bottom end again!!

Dave

JSE · Postby **JSE** » Mon Jul 16, 2007 11:46 am

what motor will you be putting in this time b6 bp?

Sheck · Postby **Sheck** » Mon Jul 16, 2007 11:35 pm

actually, i'm just gonna replace the woodruff key and crank bolt and timing belt pulley for a temporary fix, then i'll just get my big nose B6 ready for install. After that i'll start looking into a B6T bottom end or at least the rods and possibly pistons from one.

I'm also gonna install a better IC and up the boost to 12psi and shoot for the 200rwhp mark.

Dave

Sheck · Postby **Sheck** » Sat Jul 21, 2007 9:02 pm

Ok just fixed this thing today (replaced damaged parts) and it turns out that due to previous damage to the crank the surface area of where the crank pushes against the woodruff key was pretty much halved. And the \"new\" damage to the woodruff key and timing belt pulley was in this area of previous damage.

Basically half the woodruff key was squashed into the cavity of the crank damage. So i'm still gonna do a once over on the spare motor and put that in, but i'm pretty sure that if the crank was good then it would of lived.

I also fitted a new intercooler and done some tweeks, i actually gained some oil pressure which means that my old piping must of been squashing or bending the oil lines a little.

I'll be hitting the dyno again once the new motor is in, this time i'll tune with 12psi :twisted:

Dave

Sean · Postby **Sean** » Mon Jul 23, 2007 11:39 pm

Hey guys, got my car back from the dyno on friday where it made 175.7hp is far from the limits of a short nose crank.

I;ve seen more than a handful of stock shoties make over 200hp.

There is at least one shortie on this forum (though modified) making about 230hp.

Sheck · Postby **Sheck** » Wed Jul 25, 2007 9:48 pm

Well if you read the post just above it clears up everything. ie the woodruff key had about half the contact patch as nomal so thats why it was failing. Thanks anyway..

Dave

Sean · Postby **Sean** » Wed Jul 25, 2007 10:35 pm

Also of note is the effect of such a worn key would have moved the torque up higher in the rev range to t the change in effective cam timing.

Was probably a dog of a thing down low though?

Sheck · Postby **Sheck** » Fri Jul 27, 2007 8:10 pm

No no the key was in perfect condition, just the crank was a bit worn, then with the new found power it was enough to tip it over the edge and crush the key into the hole and there-after i got the no-low end thing, thats how i caught it before the front pulley fell off.

Replaced the key and timing sprocket so i could drive the car around till i preped the spare motor. It's going onto the engine stand tomorrow and i'll start taking a few parts off to make sure nothing is siezed/rusted etc. I'm also thinking of getting some billet oil pump gears made up but i'm not too keen to find out the price

Dave