Interference engines! The sr20det is one you know.
Well I didn't know what that was until I finally asked. Then when I knew about what an interference engine is, I asked myself "well if so much damage can occur to the valves if a valve gets stuck open, why do they design it the way they do?"
Well I didn't know what that was until I finally asked. Then when I knew about what an interference engine is, I asked myself "well if so much damage can occur to the valves if a valve gets stuck open, why do they design it the way they do?"
Heres some other stuff I found after searching Interference engines.Originally Posted by S14240SR
Ive always wondered this......
How does an interference head work compared to a non-interference head?
Where can I find a write up on this? Specifically about the SR20DET
-Thanks
It is not just the head. It is a combination of the head, pistons and camshaft lift and timing. In an interference engine, if a valve is stuck open while the engine is rotating, the piston will strike it. This can happen if the timing chain breaks, or the cam timing is off by several teeth, or the valves float at high rpm.
Lew
Dear Tom and Ray:
You've often mentioned that timing belts should be replaced before they break, because on some cars, engine damage can be severe. I own a 1986 Honda Accord LXi. Due to a divorce, I've lost some of my service records, and I don't know how long ago the timing belt was replaced. Do you know if this is one of the engines that would be damaged if the belt breaks while I'm driving? Thanks. -- Jeff
Ray: Well, I've heard of nasty divorces before, but this is the first time I've ever heard of one spouse getting the service records. "He gets the Honda, she gets the house, the kids and the service records."
Tom: Oh, they go for everything. Trust me.
Ray: Unfortunately, your car IS what we affectionately refer to in the shop as a "motor wrecker."
Tom: The technical term is "interference engine," because the valves open so far into the cylinders (they "interfere" in the piston space) that if the valve timing isn't perfect, the valves can be struck by a piston.
Ray: The "interference" design actually increases the engine's efficiency, because the wider the valves open, the more "stuff" you can get in and out of the cylinders. But when the timing belt breaks on an interference engine, the pistons and valves can collide, and then it's "bye-bye valves."
Tom: By the way, most Hondas and Nissans use interference engines. Some other cars do, too, so check with your dealer about your specific year and model.
Ray: Since you have an interference engine, Jeff, unless you can verify that the belt was changed within the past 60,000 miles, you'd be wise to go ahead and change it now. And the easiest way to find the date of the last timing-belt change is to call your ex-wife and ask her to look it up for you.
Tom: If you'd rather sit on a hot fork than do that (hey, I've been there), you can try asking the garage where you take the car for service. It's possible that it will have a record of when you last changed the belt.
Ray: But better safe than sorry here, Jeff. This is probably not the time to be adding a car payment to the monthly bills for alimony, child support and hair plugs. Good luck.
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