So why would "spooling down/up" caused it to let go do you think? The motors age and lots of track days making it weaker?

I'd get weights for all the stock reciprocating parts and spec out lighter, stronger replacements. They won't have to be forced induction beefy but less reciprocating weight would be a bonus on an n/a motor along with anything to reduce friction.

wow,
that's a really heated up looking rod it spit out-unsure what your oil temp's are looking like or even the oil type/intervals.
I'm over 82k & drive the (@#*%) out of mine at times & even bumping off the 7800rpm limiter,seen engine oil temp 240-250 & never had the slightest rattle.
Mind you/only have 320whp...but I will push it on a regular basis.
your's may have had a loss of oil pressure,at some point in time.

Just realized you had an 09. Could have been a rear timing cover gasket issue. They're known to degrade and cause a loss in oil pressure.

That is a near- perfect example of failed big-end bearing seizing, tearing the gudgeon pin (little-end) out of the piston and then cutting the engine in 2 and generally self-destructing ........

You have an oil problem of some kind I would think. It could be pressure as a consequence of bearing wear (clearances too great for required pressure), or it could be cr4p in the oil causing bearing pickup between rod and crank but to avoid it happening again, you need a diagnosis on what happened.

This requires a pro-engine builder to assess ..............

Why don't you give Clark @ JWT a call and email him your photo's ..........

With the much heat in the rod, the crank will be FUBAR as well ........... time to start again with another block I reckon.

Charles' (Phunk) sump is good, but it will have limits and you may have found them. What tyres are you using (how much lateral grip is being generated) ........ are you logging anything (looking for tell-tale pressure fluctuation) ....... there is a diagnosis process you can go thru

This needs a serious review before just building another engine.

It could be dry-sump time - worst case.

1.3 gs. Toyo RRs (18x275)
I suspect either oil starve due to failed non nismo oil gears or due to limits of pan capability. I'm building a dedicated track car this year so won't be tracking the z much going forward but once we tear down we'll diagnose the fail and possibly put in an acusump and warning light for pending oil pressure drops (Off the acusump)

Great input guys!

I'll send more photos as we tear down

Question should I have a local machine shop with good experience build up a long block or order one from IPP or Z1.

(I love their stuff, but Z1 seems a little pricy by comparison)

Help please, I blew my motor and need to plan the rebuild
 

I'm thinking the stage 1 IPP 11/1 compression built long block with Nismo billet oil gears and an acusump. As a start. Recycle my 400 hp kit and look at the crank. I can't use an ATI fluid harmonic dampener (no dry sump). So I'm probably stuck with the OEM dampener.

If the crank broke from harmonics I'll put in a closer to stock weight flywheel. Instead of my existing lightweight one (which I love )

Thoughts??

Call Z1. There is a reason IPP is cheaper. Do not skimp or you will be doing this again.

Why can't you use an ATI damper?

ATI made a pulley that works with our stock setup. Might have to call MA motorsports to get one. I have it and it really smooths the engine out in the higher rpm. Love it.

Good info. I was researching and only saw dampers that work without a dipstick (dry sumped). I'll call ATI and get the real story.

I don't think harmonics blew my crank but at this point anything is possible.

I have the ATI damper also. MA motorsports is your friend.

I have the ATI dampener from MA Motorsports too.

If it was rod bearing failure. The rod bolts could have stretch enough the let the bearing spin. I've had this happened to me. It was hard to pin down because all the parts was new.

Link to the most recent (2nd) group buy on here.
These were the standard replacement ones.
http://www.the370z.com/group-buys/11...round-2-a.html