Q8 6.0

Need lil help to make me understand what the f happend

I was at wot and at 10psi boost at the end of third gear around 6500rpm my belt broke it was violent made small dent in my hood..

Next day I installed new belt went to drive and my oil pressure was very high and at wot I can see blue smoke from exhaust and at wot oil comming out from dipstick I think from the high pressure looks like a piston ring damage.

My question is has anyone seen this before is it normal to dameg piston ring from broken belt or was it just coincidence

I have radix on lq4 low mile and I always use mobil1

Nflddog1000

Compression test ?

Q8 6.0

It. Has very serious blowby,compressed air getting into crank case and pushing oil out from everywhere.

I am looking to do 408 strokes I was looking at Texas speed and performance 408 stroker rotating assembly they have many piston sizes can anyone recommend which size piston to get Maybe 9.5 compression or lil higher I have lq4 317 heads and radix 2.7 pulley about 10psi .

Ferocity02

iTrader: (59)

Definitely sounds like some ring/piston damage, which can register in oil pressure. Might be coincidence, or perhaps something in the Radix broke off and went into the cylinder? Either way, sounds like you're in for a rebuild, and I would inspect the Radix while you're at it.

Q8 6.0

Loool didnt think broken belt would do this damage... Just a Warning check ur crank pulley bolt mine was loose and the pulley moved forward brok the belt, Yes I checked the radix its removed already all ok just the 2.7 pulley is damaged..

Anyone know the perfect size piston to get for 408 rotating assembly with 317 heads with 10psi radix.? I am thinking diamond flat top is it to high compression will the valve hit the piston? help please

Q8 6.0

WARNING...
Ok just update 4u I found what the problem...I damaged my piston because at high boost the injector O ring was leaking air and fuel on one of the pistons. I have taller Simans injectors and I used a lot of washers on the radix fuel rail. Well looks like on one side I needed one more washer and I didn't so one of the O rings was pinched and cut.
Here is a pic of the piston looks very weird the top of piston is clean and top ring looks new the damage is second ring and oil rail only

smokeshow

iTrader: (16)

That blows

TIM Z

iTrader: (12)

Wow that sux. Good luck with the rebuild.

Thanks for sharing what happened .

Q8 6.0

Hey no problem just thought to share maybe this will help someone out. I'm just happy I saw this before I blew up the new motor. This also explains why I had misfire in that cilindar..

02'Z71ONDUBZ'

iTrader: (8)

That's borderline blowing up a motor... How is the cylinder that piston came out of? Sorry for your loss.

Just throwing this out there. Your looking at spending some coin on the rebuild and with the increase in cubes, its time to go turbo. The 112 would be so far out of its efficiency range, I'm not even sure you could hit 10lbs on a 408.