There has been considerable controversy on whether or not the 3.0 L 12 valve engine is a valve bender even though it is listed as non-interference. I truly donÆt have the answer and I have heard opinions and testaments going both ways. I just had an interesting conversation with an automotive machine shop owner (Bill) this morning. For what it is worth, here it goes. About ten years ago, this shop was contracted to machine the heads of a dodge caravan 3,0 L 12 valve that had leaking head gaskets. (External) He claims that he machined the heads approx. .020. The shop installed the heads along with a new belt and water pump. About two months later, the water pump seized and the belt broke which resulted in some bent valves. (He did not remember how many and which valves) The shop offered to repair the head, belt and pump problem but the vehicles owner wanted a new engine and would accept nothing less. The owners sued the shop for faulty work, the pump manufacturer for defective part and the machine shop for machining the head in excess of factory specifications. Bill had the heads and attempted to find a combustion chamber volume specification. He was unsuccessful. So, he did something that I thought was pretty unique. He obtained a head from a low mileage engine that had not been touched and he replaced the bent valves in one of the heads that failed and took them to the shop where the engine was. Modeling clay was put on the top of a piston. The heads were installed one at a time without a head gasket. The cam was rotated with first an intake fully opened and then an exhaust. The engine was rotated by hand while each valve was set at full open. He claims, there was only.018 difference of valve depression between heads. Now the real interesting part, he told me the final clearance between the valve and the piston was .007 on one head and .025 on the other. I understand this is without a head gasket but scares me. Can anyone with a 3.0 confirm this? By the way, Bill said after all his research, the insurance companies decided to settle out of court with each sharing the cost of a new engine.
Conner