Pistons hitting valve after headgasket job

[4g64fiero]

I just finished replacing the headgasket on a motor I bought from the junkyard. It appears the motor has been milled down aggressively as even the depth checkers on the head have some machine marks on them. I did the timing, correctly mind you, and the valves seem to touch the pistons when cylinders 2&3 are at TDC around 90 degrees crank rotation. I cannot turn the motor more than this. If i rotate it backwards, same story.

So what are my options? Can I just buy a thicker headgasket? I tested the valves and they are seating correctly.

This is a stock 6 bolt motor with a 2g oil pump BTW.

 

[donniekak]

A 2g oil pump timing mark is incorrect for a 1g crankshaft timing gear.

 

[4g64fiero]

A 2g oil pump timing mark is incorrect for a 1g crankshaft timing gear.

I am using the 2g oil pump so I can keep the 2g crank pos sensor thus I am using the trigger plate for timing just like a 2g. It should time correctly.

 

[Cdc1221]

What did the pistons look like? Were they protruding from the block any? Could the head be decked too severely? These are the things you really need to check

 

[4g64fiero]

What did the pistons look like? Were they protruding from the block any? Could the head be decked too severely? These are the things you really need to check

The pistons didnt exceed deck height from what I could tell, but I know the head was decked aggressively, thats why I am asking what to do to make up the difference in head height. I am assuming a thicker head gasket is safe?

edit: pretty sure I put the trigger plate on reversed. That would explain things.....
edit #2: yep its backwards. Stay classy Chicago.

 

[Cdc1221]

Hahaha, yes you can use a thicker head gasket

 

[Kapok6]

The pistons didnt exceed deck height from what I could tell, but I know the head was decked aggressively, thats why I am asking what to do to make up the difference in head height. I am assuming a thicker head gasket is safe?

edit: pretty sure I put the trigger plate on reversed. That would explain things.....
edit #2: yep its backwards. Stay classy Chicago.

I chuckled.

Glad you got it figured out.