Thanks guy's, great post. FYI for those of us who are too lazy to wiki things...
A "interference" engine (like our 2.7) is a motor whose combustion chamber is designed in such a way so that the cylinder valves; at the extent of their travel ( full “lift”), would contact the piston if (at the same time) it is at the top of it's travel (TDC). E.G. If your motor is running and the chain breaks the valve train will stop moving, leaving the valves’ extended and out of phase with their cylinders’ piston. So when the piston reaches the top of the cylinder it will collide with the valves, and BANG!!!... Catastrophic engine failure.
So… if you should fail to correctly time the valve train with the crank rotation after a rebuild or as here; changing the timing chain. When the engine is spun you will (at best) flatten your valves and they will fail to seat. It is common (but not a rule) that engines that are designed as interference engine will have a timing chain for added durability and protection against breakage. Whereas; a non-interference engine will have a rubber timing belt that is less complicated and lighter (reducing drive losses).
For more info please consult your local librarian, they miss you.
'96 Tacoma, 225K+, 3RZ, 4x4, Manual, 3.56's
Custom Intake, LC Header, Cat, Exhaust, Electric Rad fan and Oil Cooler, BFG's, 2.5 SAW's and matching leafs
Last edited by Speedin'Ian; 08-25-2009 at 09:39 PM.
Reason: lack of proofing