Well i went on the dyno today for retouching my tune after the new heads(prc ls6 stage 2.5),morel lifter etc etc.

-First run: i made 1 whp more than with stock head...weird smoke and smell(burn smell),we decide to go to the second run to do some test;
-Second run: at around 4200rpm the dipsick pop up and there was oil all over the place,there was also a lot of pressure/smoke coming out of the valley cover(front and rear),we also saw that i lost nearly 65 whp at 4000rpm from the first run...the car doesnt answer really well to throttle now;
-Third run(test run) at 4000rpm it smoke like hell from the valley cover,dipstick pops again,smoke,smell...everything.

No cooling leak,temp stay right a 190degree,idle fine.I did a test and cancel the catch can and pcv valve so there would be no restriction between the crank case and the air intake but it did the same thing...

So to my mind all the new top end put too much pressure on my block that did suffer from heavy piston slap and now it compress in the base...

By the way the 2 last run was some test run not heavy wot run up to 6800rpm. We where 3 guys looking on the engine bay while testing on the dyno.The idea was to locate where exactly was the smoke coming from...not trying to make some power.

I ve just bring back the car to my home(5mins from shop) and the car smoke from the exhaust and run like crap

What are you tought on that...block is shot???

 

TOO MUCH blow by means it's time to rebuild that engine. Needs new rings/pistons/boring and bearings. New short block if that's in the budget.

 

Sure sounds like a complete overhaul to me.

 

Your crankcase pressure is too high. You have lots of pressure going past the rings. Do a leakdown test but I'm guessing one or more of your pistons have a crack now.

 

Was it running normally before the heads and cam swap?

After the first dyno pull where something was noticeably wrong- you did 2 more pulls?

 

Could be as simple as a cracked piston, a complete overhaul may not be needed. Do some diagnosis FIRST, then tear it down and MEASURE things. Several people have have ring lands crack and have the piston hold together enough not to damage the bore.

 

Strike 1

Strike 2

Strike 3...out

 

It was running with the cam only(442whp) but i lost oil pressure a little due to a bad oil pump o-ring,it then began to do some heavy knocking while its was cold(was thinking about piston slap).When i did the heads and lifter i notice that 7 pistons where rock solid but the no 1 was kinda loose or slack...

After the first pull it did smoke a little from the exhaust but i must admit that i didnt really pay attention.We stop the second run at 5000rpm because it was scary The 3rd one was just to do some diagnosis and see where oil/smoke was coming from.

The car idle fine,stay at 190degree average but doesnt answer well to throttle now...

 

Right now im pissed,if i need to tear the engine apart again i ll put a new short block...when fund will be available

 

And with no diagnostics YOUR OUT!

 

So you kept running it
Its shortblock time, no leakdown needed it showed you everything you need to know.

Make it bigger and badder now.

 

I noticed in your profile that you have a "Z"-these are notorious for breaking valve springs. I'd still do a compression/leakdown test but I'd also pull the valve covers and look for broken spings.

 

Dont worry ill do some checking,i do all by myself...im just totally frustrated because i took 2 weeks to do all the work correctly(a couple of hours everyday in my driveway).And when all the top is is perfect,the base just let me down...

The heads are new(less than 150miles) PRC LS6 2.5 with new PRC .675 dual valve springs,i already got the valve cover off and everything is fine there.

 

Well, then I'm betting on a cracked piston!!

 

Strike,1,2,3???? you need a mechanic my friend!