(that's a 3.0 12 valve ohc)
is this an interference engine?
what happens when the timing belt breaks?

thanks

 

yes the 6G72 IS an interference engine... if the belt breaks the engine will lunch itself...

 

i.e. On an interference engine the valves will hit the pistons if the timing belt breaks. I would expect on our engines the failure point will only be the valve stems bending and requiring R&R but perhaps someone who's experienced this or know of it happening 1st hand, can elaborate.

EDIT:
I should add that I've been told by folks far more knowledgeable than probably most on here that my 3.0L SOHC engine is NOT an inteference engine. It is a Gen I (1990) SOHC, 12 Valve 6G72.

 

If your lucky you will have no bent valves. At worst you will have all the valves bent and the head will be destroyed.. and you will have nice holes in the pistons.

 

I blew a belt in my 6G72 once... and it was time for a new engine.

 

I read something about the pistons being shaped in such a way that the 6g72 could be considered a non-interference. The pistions had a bowl shape on the top or something.
I couldnt rememberif the article was about thestock pistons, or aftermarket pistons or if it was even the 6g72 or the 24 valve or what.It was a racing performance type website, so there is no telling what I was reading...

Anyway that is why I asked. I dont want to find out the other way.

 

okay. tell me where I'm wrong...
I went looking for that page I was reading and found it.
here is an exerpt, butif youread the page you will see that it is abit confusing...I am not sure if he means the 6g72 that is in the 1989 montero.


"A BIG question that runs rampant through the mailing lists, and seems to be full of disinformation, whether these motors are interference or not. By interference, I mean if the timing belt breaks, will the pistons and valves hit. I'll let Robert Carter answer this oneā€¦
Read on: Straight from '88 Van FSM Page 9-51 "Pistons: Are aluminum alloy with a steel strut, short height, and thin wall so as to be autothermic and light weight. The piston head with valve recesses, in combination with the cylinder head, forms a compact spherical head WITH CLEARANCE FOR TOTAL VALVE LIFT WITH PISTONS AT TOP DEAD CENTER." I think this answer's the long debate on whether or not the 3.0 is an interference engine.
And for the record, my 87 and 92 FSMs (Factory Service Manuals) back this up too."

you can read the whole page here:
http://home.pacbell.net/fong8/gstuff/6G72.htm

 

I think he may be refering to the 6G72 in the 3KGT and Stealth.

 

[*]The Chrysler version of the 12v 6G72 SOHC is a non-interference engine meaning that no matter what you do, the valves are not going to smash into the pistons. If you bump up the compression to 10:1 or are working with a 3.0 engine from a Mitsubishi Montero or Diamante, you do have an interference engine and you will need to take extreme car to make sure the cams don't rotate while the belt is off.
http://www.kmperformance.com/techcen...imingbelt.html


'ere we go!

 

Ouch, my ego, lol. This may be right, but according to the people at the Mitsu. bay in Tampa (where Ive brought my car countless times) the 6G72 in my 3g IS an interference engine. Then again, they arent really the best techs Ive ever met...