imp
Explorer Addict
- Joined
- November 12, 2009
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- Year, Model & Trim Level
- 59 Ranchero F250 D'Line
Anyone willing to take a crack at this? I've been trying to imagine why, in this age of OHC engines, anyone would offer an interference engine? Obviously, both types exist. I picture the valves, 2 of them by example, "using" up a certain amount of combustion chamber volume, into which no piston dome should ever intrude, but it's very small, just a few cubic inches, compared to cc volumes of 40cc and more.
If crankshaft and bearings are operating where they should be, the pistons always come up to the same place in their cylinders. Above and around that top area is the combustion chamber into which the valves protrude when open. Good design would disallow piston tops from interfering there. Yet, they do, often, causing various broken parts.....dead engine.
Happens when valves go "out of time" for whatever reason, but shouldn't if clearances are designed in: valve timing is then unimportant. What basic facts am I missing?
If crankshaft and bearings are operating where they should be, the pistons always come up to the same place in their cylinders. Above and around that top area is the combustion chamber into which the valves protrude when open. Good design would disallow piston tops from interfering there. Yet, they do, often, causing various broken parts.....dead engine.
Happens when valves go "out of time" for whatever reason, but shouldn't if clearances are designed in: valve timing is then unimportant. What basic facts am I missing?