Brand new FG crank for build

[Zlat347]

Hi guys, 

 

Are people using there old cranks for 1000hp builds or buying brand new cranks. 

 

My budget doesn't allow for a billet so I figure best option would be to start with a brand spanker FG crank. Any body else done this? 

 

Is it worth heat treating them? 

[k31th]

if your budget doesn't allow for a billet crank, then 1000hp at the wheels should not be your aim... 1000hp at the crank the stock crank will likely be fine for a reasonable amount of time assuming all else is done well in terms of the modification pathway.

[Zlat347]

Plenty of barras going around with 700rwkw? with supporting mods of course. cams, ported head, some grout, girdle, torington ect ect

[k31th]

700 is way more than 1000hp at the crank, that's more like 550-600kW at the wheels.

[Zlat347]

Any guys on forum running over 1000rwhp on standard crank and their experience? 

[k31th]

there's almost nobody running over 1000rwhp in general... you could probably go through them all and ask them (or read their build threads) what crank they have.

[HI PSI]

In had my crank nitrided and stress relieved. Notvquitecat 1000, but we had it up to 830 rwhp and had plug issues..  It'll be good for 1000 rwhp.  Np.... 

[Typhoon]

This crank was also treated to hold 1000hp!

 

My brother’s crank broke at 750hp on Nizpro’s engine dyno 10 years ago.

 

I know of a stock N/A crank that has also broken in half.

 

Its just a roll of the dice.

 

I have 1000rwhp and run a billet crank.

 

As Keith said if you don’t have a budget for 1000 wheel then maybe you should lower the expectations a little.

 

1000 at the wheels is also a hell of a street car and not really needed to be honest. 

 

 

 

Edited 24/08/20 01:41 AM by Typhoon

[Zlat347]

On 24/08/2020 at 11:40 AM, Typhoon said:

This crank was also treated to hold 1000hp!

 

My brother’s crank broke at 750hp on Nizpro’s engine dyno 10 years ago.

 

I know of a stock N/A crank that has also broken in half.

 

Its just a roll of the dice.

 

I have 1000rwhp and run a billet crank.

 

As Keith said if you don’t have a budget for 1000 wheel then maybe you should lower the expectations a little.

 

1000 at the wheels is also a hell of a street car and not really needed to be honest. 

 

 

 

 

Wow 750 fly wheel is about 400rwkw roughly. I think your definetly right about rolling the dice.

I've got two mates running 1150hp at wheels for the last 2 years and haven't let go as yet. In lighter chassis conversions.  

 

Did you ever find out the cause? I assume was a built motor. 

[Typhoon]

Back in the day who knows why it broke. Simon held the view for a long time that these cranks were questionable above 7000rpm and that the BARRA had inherently poor harmonics. Clearly things have moved on.

 

The broken crank pictured was a manual car and the crank was advertised as an almost 1000kw capable crank.

 

I have seen an N/A engine with a broken crank shaft right through the middle of the crank, nothing odd about the motor, a relatively clean average km motor.

 

These cranks break, it’s just guys and shops don’t talk about it.

 

I have heard of others too but only ever seen three. 

 

For a guy on a budget build then heaps of power can be had on a stock crank, but if it was to break I personally wouldn’t be surprised.