you have to go at least 40mph + to bend a valve in these motors. I know i work at the dealer and i have two here waiting for new motors.
ok... for the record.. the BOOK says the engine is a NON interference engine here is the link... clicky clicky
as to the valves being shut... UNLESS your cam is OUT of the car.... atleast half of them are still open at one point or another.. I have snapped a timing belt ( too much boost, and blew the bottem end apart)
look I am Mazda certified and have been through plenty of training. i am an Ase auto technician I don't just turn wrenches. Like we discussed in the class last week any manufacturer can tell you that their motor is non interference. just for you to buy it and i am not saying that evertime the belt breaks that this motor bends valves it is a case by case bas-sis. just trying to start the motor really is not enough rpm to do any damage. Also you have to remember that the Mazda manual is in Japanese first then translated to English. so sometimes their meanings are not the same as ours.
I don't buy this. If your motor is interference and your belt breaks, you will always bend valves due to the inertia of the motor. Unless you've got some retarded high compression ratios that stop your engine in 1/4 of a camshaft turn or less, I don't think you can say that an interference engine will only sometimes bend valves.
If you can provide a specific example of an FS-DE engine with bent valves (with pics), great. Otherwise I maintain that our motors are non-interference, and that the Gates belt company is wrong.
^^ If I read this right, this would be OTHER than stock specification......and quite possibly interference
his motor would have to be something BESIDES stock, and this is why... ( when i find out where it said non interference ill post it i just cant find it but i know it says it some where.
if you look at the piston design, there are domes where the valves have clearance, first off... secondly our piston comes to the top of the block, and stocks.. it does not extend past the deck portion, there is a .16mm gap that is allowed for expansion of the pistons, ( that is from wiseco when i spoke with them earlier today