well, alot of my friends and i came to the conclusion that i melted a piston due to pre detonation. but i remember that my oil press. gauge always read like 15ish and 0 at idle. could unsufficient oil have been a problem or..?

 

detonation would happen no matter your oil pressure, it happens when the air/fuel ignites from the heat of compression instead of from spark. you need to either run a higher octane to slow down the burn, or lower compression ratio, or richen your mixture (also slows down burn).

if the engine is stock, then you need to figure out why that cylinder is running lean, this will also cause detonation. clogged injector might do this.

 

ok well my first mistake was buying an ls/vtec already swapped. after a while the piston finally gave in. i was running 87 octane for like 2 weeks then it gave out. when i pulled the motor apart i saw it had CTR pistons instead of the stock ls pistons like i thought it had. thats why it detonated i think more than anything. but on a different note, the autometer a/f gauge would always be bouncing back and forth all day until i got on it. then it would always read really lean even going back to normal driving it would stay really really lean??? whats up with that

 

Air/Fuel meters are worthless unless you have a Wideband. And yea... an LS/VTEC with CTR pistons probably wanted a tad more than 87 octane.

 

lol yea just a "tad" more. so is this normal of a/f gauges to do **** like this, cuz i really dont want this to happen again on my fresh build? and im def gonan use at least 91 octane.

 

<TABLE WIDTH="90%" CELLSPACING=0 CELLPADDING=0 ALIGN=CENTER><TR><TD>Quote, originally posted by 92eg6lsvtec &raquo;</TD></TR><TR><TD CLASS="quote">lol yea just a "tad" more. so is this normal of a/f gauges to do **** like this, cuz i really dont want this to happen again on my fresh build? and im def gonan use at least 91 octane.</TD></TR></TABLE>

If you run a wideband O2 sensor than the A/F Guage can work effectively, it will be nothing but a light show if you use a stock O2.....

 

ok, well just curious.

 

bump for this guy!