i think zkiller nailed this one....

 

Whatever it ends up being it is not purely indicative of how stroker motors behave. More to do with proper assembly and experience with building these motors. Most well built strokers run like a top void of any issueslike these.Word to the wise, be careful who you let build an engine for you.

 

my car got progressivly louder then finally broke. main bearings went bye bye

 

I would strongly urge you to have someone who knows what they are doing do a couple things...

#1 - a compression and leak down test
#2 - take apart the valve train and check the valves and guides
#3 - Recheck the entire vortech kit for any boost leaks
#4 - have a professional check your clearance and make sure it's correct and tight for your specs

I really doubt it's just piston slap. The idea of fouled plugs makes more sense to stumble in the upper rpm ranges and boost levels. It may just be as simple as that but if you went to 2 dyno's - they should have checked the plugs numero uno.

I hope I'm wrong and could never know without hearing it first hand but it seriously sounds like valve float to me and that = bad anyway you slice it.

Good luck.

 

James from RWTD put a brand new set of plugs in it before he dynod it. It didn't make all the hellish noise while on his dyno, just a little slap. It never lost any power either while on his dyno in the upper rpms like it does now. He's taking the car next weekend to a friends house that helped me put my engine together. Were going to pull the motor and take the whole thing to a engine guru in Mobile. I'll let you guys know what it ends up being.

 

Now it really sounds like the spark plugs. How much boost is he running? Almost sounds too like you guys aren't gapping the plugs. For 10+ psi, you really want to run HTO's or something else that's a colder range and you also want to gap them somehwere between .028 and .034

Ifd it was something in the valve train, it wouldn't go away on one dyno to the next - it would be constant. I would try correctly gapping a set of HTO's before pulling the motor apart. You coudl be just blowng out spark at 10 psi. A good tuner should easily be able to tell you if that's what's happening on the dyno.

Good luck.

 

That's exactly what I was thinking, maybe they forgot to Gap it properly, because it's doing it when 10 lbs of boost kicks in, maybe blowing the spark away.

 

let us know what you find out...

 

It's not the plugs. They are one range colder and gaped properly. The motor will be torn down next weekend so I'll let you guys know then what it is.

 

After reading the replies... I'm definately with zkiller. I remember researching stroker kits, and reading in many places that the 302 kit or even 301 was too much and the knock sensors would have trouble and need to be turned off. Many places said 298 was the prime choice. I'm no expert so I can't quite go into detail about what I'm talking about, but what zkiller said sounds very very familiar.