problem with motor

[unrivaledAWD]

i just recently finished taking off the head off my 4G63 because i want to check if i had bent a valve when my timing belt had broke(cars been setting for over a year).good thing is NO BENT VALVES!!!! but the head is cracked!!!!. now i'm looking at the pistons and i believe that they are stock. i don't know how to tell on pistons but they say 4G63 on them which make me wounder...the lady i had bought it from says she has all the paper work saying all this motor has been done but i'm kind of mad now..

my questions are:
how could i tell if the pistons are oversized?
why would my head be crack from setting so long?
if i bought a copper head gasket would it prevent it from cracking?

i'm a newbie to DSM so a little help here guys

 

[1992awdlaser]

how could i tell if the pistons are oversized?

Measure the cylinder.

why would my head be crack from setting so long?

I would think that it happened when the last person torqued the head on. Or the engine was ran really hot at one time.

if i bought a copper head gasket would it prevent it from cracking?

Do you want to know if it would fix the problem wit the crack in the head? Or do you want to know if it will prevent the next head from cracking?

 

[lgoss5127]

a copper head gasket would help prevent the head from cracking in the future.

 

[1992awdlaser]

a copper head gasket would help prevent the head from cracking in the future.

No it won't. If anything a composite gasket will prevent it since the composite gasket will be able to "cushion" the head since it is soft. The copper one won't be as forgiving when the head is being torqued down and will make the head have a better chance of cracking due to if you over torque it.

 

[RT-AWD]

^^ he's right. you need a new head you don't want to drive around with a cracked anything