dont wanna burn pistons

[nate@truetech]

ok, im looking to do some tuning work, and since its a stock motor i gotta live with that.

Could anyone tell me more about my stock t1's pistons and such? How resistant are they to high combustion temps and lean cruising conditions?

i dont wanna blow anything up before i can afford a build...

im tuning for economy btw

[turbo minivan]

stock pistons are preaty good for a little bit of abuse. i broke 4 pistons before going forged, each at about 20psi on regular pump gas (stupidity) and from what i see from my experience and from others breaking pistons, 20psi with crappy gas seems to be the limit. but... there are guys out there making 300+hp with stock pistons with the right fuel and the right tune, so its all about how you tune it. as for melting them, i never melted any of mine, but they start to break down in the 1600*-1650* range.
as for "lean crusing", realy lean conditions will cause detonation and melting if your on the throtle way up in the RPMs, but just regula driving, being lean wil show itself by how your spark plugs look. see below...
Reading Spark Plugs by Gus Mahon..

Reading Spark Plugs: Mild detonation, that you might not hear, is evidenced by small "salt & pepper" specks on the center electrode insulator. (white porcelain) They're tiny specks; the light ones ("salt") are tiny molten droplets of aluminum that have hit your insulator, then cooled off and hardened on it. The dark specks ("pepper") are carbon specks that have been blasted off of the cylinder head and piston top.

Another common bad sign is a slight rounding of the edges of the plug's electrodes. The corners of the electrodes should be sharp 90 degree angles, not rounded. This is actually a sign of leaning out, but leaning out leads to detonation. If your plugs are OLD, this is normal. But if you put in fresh plugs, and a few passes later they're slightly rounded at some corners, you're too lean. These signs beg for more fuel, and/or less timing advance, and/or less boost.

Ever wonder how even your fuel distribution is, but can't tell by the white center insulators, because of today's unleaded gas? Just throw a little 104+ octane booster in your tank and drive around for a while. You will then have a reddish residue on your plugs. The reddest ones are getting the most fuel. The whitest ones are the leanest cylinders.

[nate@truetech]

good info, thanks!