1996 saturn head problem sohc

1996 saturn sohc 1.9 liter
put diaonostic computer on the car , getting misfire on cylinder #2 , then
did a compreasion test , okey now we got problems . so take the head of the
car , and one of the valves are shot (not that big of deal send out to get
fix) so they tell me that the cam is beyond repair, okey so get me another
cam (used) so the shop puts it in(you would think they would check the lobes
to see if they where the same ) and i get the head back . cleaned up nice ,
put the head on set timing to where it is suppose to be , put it all back to
geather , now here is where the problem starts , with the plugs out i roll
it over till i see i got oil preasure then i hear crack . (piss me off) so
i take the cover off and there is two rocker arms busted off (ahhhhhhhhhh)
they where all checked befor hand to make sure where all set right . and as
they are self ajusting no problems there , my question is do you people
think that maybe that the wrong cam got put in ? person said timeing , but
all was set to spec and loke said no plugs where in it . so any help that
you may be able to send my way would be very help full . thank you to all
that reply

 

Sounds to me like the timing chain wasn't properly indexed.

 

Whenever I have done anything to a car which would effect the timing, I
always turn the engine over by hand using a breaker bar on the crankshaft
nut. This way, if anything is going to bind up and break, I can feel it in
my fingers before damaging anything. After spinning 360 degrees I can be
confident that nothing is going to snap/crack/dent/ etc.

-David

 

Except in this case the new cam may have had the wrong timing gear
on it, meaning that you wouldn't notice a problem for several
revolutions.

 

Two rev's

Wes

 

I thought about David's comment a while and realized he's right. If the
number of teeth on the camshaft sprocket is not exactly twice the number on
the crankshaft sprocket, it could take several turns to ruin the engine.

But, if you aren't an absolute idiot, and you put the correct sprockets into
the car, then two turns is it.

 

Two revs for the right gear, to go entirely through a cycle. Would
take more for the wrong gear. Say it's 38 teeth vs forty. Each rev
of the crank is 1/2 rev of the cam. So each two revs of the crank
advances the cam by two teeth. Figure that worst case is when the
cam is 90 degrees out, or around 9 1/2 teeth. You'd need 9 1/2 revs
of the crank to reach 90 degrees.