I am doing a head swap on a 1.6 16 valve motor. My question is can I use the old head bolts or do I need new ones?

worked in the fastener business for years and once they get torqued they are supposed to be changed but in a different world we re-use them all the time. I've done many and never changed one.

They will all tell you to re-use and we all do it...is it right?

zukimoo said it right.

Its "recommended" that you go with new ones.
I to have gone with old ones and seen many other people go the same rout. 
So far no one has run into a problem. 

Amilla

Well I am cheap, so I will use the old ones. sense I have never done this before is there a book I should get to see what to torque the bolts and time the motor right when I put it together?

The best thing to do is pick up a Factory Service Manual (FSM).

The second best is to jump over to Acks Faq (www.acksfaq.com) and check out the FSM on-line.

sense I have more than one car I think it would be wise for me to get a manual. I don't know where I would find one though.

Ebay!
It will probably give a bolt length spec. If yours r longer you must replace.
torque spec is likely to be an angle in degrees.

napa has a new set for $20 ,
with no allen wrench hex key tops.

best deal around. and they do get weaker ever time you heat cycle the motor.

but nature is forgiving , sometimes

zukimoo said it right.

Its "recommended" that you go with new ones.
I to have gone with old ones and seen many other people go the same rout. 
So far no one has run into a problem. 

Amilla

Yes I have always been told to use new ones, but I was forced in a pinch one time to re-use the old ones and I never had a issue.

well I am in a little pinch. the parts are $400 plus head bolds if I can afford it.

Best you can do is to make sure the threads are cleaned of all old locking
compound and the block holes are chased with a tap so they are clear of
any rust or locker, then oil the threads and head  before you put the bolts in

Wild