Oil Pressure Drop On Boost.

[EAT26]

arigato gozaimasu Mercury Motorsport-o-

Stop trolling...

[GTRNUR]

Pretty much what my number 6 looked like when it let go....

it had standard pistons running 285rwkw.

what generally causes the piston to break away like that... is it just cause they're weak? or is there other contributing factors?

Detonation/pinging. It smashes the ring lands off pistons, and gives the rod bearings a good hammering at the same time. A look at the piston crowns and rod bearings, and the crank rod journels may reveal more.

[GTR_JOEY]

Detonation/pinging. It smashes the ring lands off pistons, and gives the rod bearings a good hammering at the same time. A look at the piston crowns and rod bearings, and the crank rod journels may reveal more.

hmmm interesting thanks for the reply...

it was my number six cylinder and all the rest were fine

im assuming because that cylinder is at the back of the engine it gets alot hotter causing it to detonate/ping

Also just before i noticed the car blowing blue smoke i took the car on a long drive from sydney to Wagga,

the car was loaded up pretty heavy, id say it would have been carrying an extra 350-400 kg then it usually would.

could this cause the engine to detonate/ping due to the extra load?

[Duncan]

Yes I have....although I think it was load, not boost. I spun a big end bearing shortly after. seriously.

I get the points. Wait until the big ends are checked.

f**ked bearings/clearances = low oil pressure under load.

[GTRNUR]

hmmm interesting thanks for the reply...

it was my number six cylinder and all the rest were fine

im assuming because that cylinder is at the back of the engine it gets alot hotter causing it to detonate/ping

Also just before i noticed the car blowing blue smoke i took the car on a long drive from sydney to Wagga,

the car was loaded up pretty heavy, id say it would have been carrying an extra 350-400 kg then it usually would.

could this cause the engine to detonate/ping due to the extra load?

A lot of things cause detonation. Perhaps it was running a tune on the razor edge of safety vs death. An especially cold day or a little blow by oil in the intake could have been all it would take to push it over the edge.

The blue smoke you saw most likely happened after the damage was done. The rod bearings will tell the rest of the story.

[GTR_JOEY]

yeah it started to blow the smoke a week or two after that long trip, ill double check the rod bearings

cheers mate

[chocco]

arigato gozaimasu Mercury Motorsport-o-

LOL!!!

They add another one to their belt of hopeless tunes...

[Rolls]

what generally causes the piston to break away like that... is it just cause they're weak? or is there other contributing factors?

They can withstand 400rwkw if tuned correctly. The issue is heat and detonation. At those kind of power levels all you need is it to go slightly lean, or you be running it really hot and on the edge of detonation, hard corner and surge = lean, or putting it under load that it hasn't been tuned for and the tuner didn't richen/retard those cells making the motor detonate.

Basically down to tuning/fueling/cooling issue.

[GTR_JOEY]

in that case i would be suspicious of the extra load the car was carrying on that long trip a week or two before it let go....

ive been informed that the PFC doesnt retard timing when knock levels become high,

so i guess what ever load the tuner puts the car on the dyno is what the tune is made for

cheers for the reply mate

[Rolls]

A good tuner will tune the cells above what is being used extremely rich and retarded, much like what nissan did from the factory, hence the R&R feature everyone sooks about, at least their engines don't blow up though.