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John Willey

AU 4.0 standard crank - how much can it handle

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Cranks don't so much handle "power" more like RPM. Folks run upwards of 500 hp running boost on a cast crank but they keep it below 6000, keep the timing sensible and get it balanced and seem to live ok. Harmonics kill inline cranks more than anything else.

 

Nope, as far as I know, all bottom ends are equal. XR6 spec got a very mild port with slightly bigger valves, cam and slight bump in compression but no other mechanical differences.

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Cranks don't so much handle "power" more like RPM. Folks run upwards of 500 hp running boost on a cast crank but they keep it below 6000, keep the timing sensible and get it balanced and seem to live ok. Harmonics kill inline cranks more than anything else.

 

Nope, as far as I know, all bottom ends are equal. XR6 spec got a very mild port with slightly bigger valves, cam and slight bump in compression but no other mechanical differences.

 

The only difference between au xr6 and standard bottom end is the standard engine uses a half thrust bearing whereas the xr6 uses a whole one

Is there much that either of you blokes don't know?

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The only difference between au xr6 and standard bottom end is the standard engine uses a half thrust bearing whereas the xr6 uses a whole one

 

I'm guessing that's due to a larger portion of them being manual yeah? Was the clutch beefier too?

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Cranks don't so much handle "power" more like RPM. Folks run upwards of 500 hp running boost on a cast crank but they keep it below 6000, keep the timing sensible and get it balanced and seem to live ok. Harmonics kill inline cranks more than anything else.

 

 

Nope, as far as I know, all bottom ends are equal. XR6 spec got a very mild port with slightly bigger valves, cam and slight bump in compression but no other mechanical differences.

 

 

 

 

 

The only difference between au xr6 and standard bottom end is the standard engine uses a half thrust bearing whereas the xr6 uses a whole one

 

 

Is there much that either of you blokes don't know?

 

I only know how little I know

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Yeah it is, the only non off the shelf ford parts are the pistons and the ecu, other than that its all ford.

The first engine split the block in two straight down the middle when number three let go at 7500rpm!

This one still has a standard head too, no port work or bigger valves.  Big cam though.

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