help with timing

[g3mustang]

holly hp 427 11.1c 220 afr heads e85. was having a horrible time with breaking up issues and blowing up pistons. We lowered and raised timing, added fuel and decrease fuel nothing helped. thought it was jumping spark from the Fast distributor. So ive gone coil on plug. wanted to break in the motor by cruising it around. did a couple quick wot pulls and some half throttle stuff. well I blew a head gasket! I feel like it was maybe due to to much timing under light load. zero vac and zero boost is 31 degrees. so half throttle and no boost is little bit more timing. Please help.

[SlowBox]

Gotta be too lean. You should be .80 lambda and getting richer at 0 vac/0 boost. The plugs will tell the rest of the story.

[g3mustang]

plugs all look good. and doesnt 11.8afr seem a little rich at half throttle?

[SlowBox]

11.8 AFR is so lean I doubt it would even light off. If you're melting pistons and popping headgaskets, the plugs will show it. There is a problem.

[g3mustang]

11.8 afr gas scale is lean?

[SlowBox]

You said the car was on E85 in your OP. If the car is breaking up, that right there is telling you it's dangerously lean. Part throttle is irrelevant here because the motor isn't gonna make enough power to hurt itself.

[g3mustang]

i am on e85 just use gas scale in holley

[g3mustang]

When at wot i commanded any where from 10.5-11.8 nothing changed

[decipha]

on e85 for max power you should be commanding .68 lambda

14.7 * .68 = 9.99 AFR at WOT

that doesn't sound like a bunch of timing, make sure the heads and deck are machined true