"Inversion"or "Interruption" engines


How can I find out which cars have inversion or interruption engines? These are engines that are close to the timing belt, so that is the timing belt is broken, the engine is damaged. This happened to my 2005 Hyundai Tucson and once it gets back from the shop after too many weeks and too much money, I’d like to find a reliable car without this problem. But when I google “what cars have inversion engines?” I don’t get very far. THANKS.


What you are looking for is a list of interference engines. If you google timing belts, Gates Rubber company should come up. Gates lists cars that have interference engines and use a rubber timing belt.


What you actually looking for is INTERFERENCE or
Try this:
Hope this helps.


You’re talking about “interference” engines and not inversion engines. An interference engine is one in which the valves hit the pistons in the engine when the timing chain or timing belt breaks or slips. It’s unusual for a timing belt to fail inside the service interval, meaning they almost never break unless you’ve pushed your luck and gone past the date or mileage you should have replaced it.

Some engines use a rubber timing belt, some engines use a steel chain. Some people have a preference for one or the other but there are pluses and minuses for both.

Interference engines have been around for about 50 years or so, so I wish you good luck in finding one that isn’t.

Please don’t take this list as anything other than the anecdotal ramblings of a mechanic and his memory. And what I say applies to “most”, not “all”, and I’m talking about late model engines.

Fords with timing belts are non-interference (save for a few Escorts from the early 80’s) and Fords with timing chains are interference.

Hondas with both timing belts and timing chains are interference engines.

Toyotas with belts are non-interference, and most with chains are non-interference.

Nissans with belts are non-interference, so are most chains.

Mitsubishis are all interference, belts and chains.

Chryslers with belts can be either, chains are almost always interference.

GMs with belts are interference, chains are either.

Kias with belts are interference.

Volkswagen and Audis are interference, but some of their engines have both a timing belt and a timing chain.

Hyundais are interference, but you already know that.


Personally, I like interference engines. Like engines that have four valves per cylinder instead of two, they are more efficient because they can breathe easier. What makes an engine an interference engine is that the valves open up wider than they do in non-interference engines, and the valves occupy the same space that the cylinder occupied when it was at top dead center. The valves open up as the cylinder moves out of the way.

I think you’d be better off shopping for a car that has a timing chain, so it won’t matter whether it is an interference engine or not. The problem you had is that your timing belt broke. Timing belts break sometimes, even when they get changed on schedule, but most of the people who have timing belts break contribute to the problem with neglect. Sometimes timing belts break because of failure of a related component, like the tensioner or pulley.

I’ll take an interference engine over a non-interference engine any day for the increased efficiency, just like I’ll take a four-valve-per-cylinder engine over a two-valve-per-cylinder engine any day for the same reason.

If you still insist on getting a non-interference engine, I still recommend you get something with a timing chain. A neglected and broken timing belt is no fun whether it’s in an interference engine or not.

Personally, I’ve never considered an interference engine or a timing belt a deciding factor in whether to buy a car. I’ve never had a timing belt break, and the cost of a timing belt job isn’t that expensive if you can do it yourself or shop around for a good price.

Lastly, I disagree with @asemaster on one point. I don’t think anyone makes timing belts out of rubber anymore. The one’s I’ve seen are made of composite materials, with steel belting woven into them.


Whitey, timing belts are composites but they are in a rubber matrix. When the rubber starts to deteriorate, the fibers of the reinforcing material gets exposed and starts to unravel. Then the belt breaks. I believe that if they used a carbon fiber belt with a silicone rubber matrix, a timing belt could easily last the life of a car and then some.


Timing belts don’t always fail by breaking. I have seen one where the belt was intact, but it had shed so many cogs that it was able to span the driving pully without any cogs engaging the teeth of the pulley at which point the pulley just spun without driving the belt. Fortunately, it was a non-interference engine.


@Whitey, there are *many *4 valve per-cylinder engine that use timing chains. Having a timing chain does not limit an engine to x number of valves.


@Whitey: I really don’t get the supposed “advantages” of an interference engine. I mean, any free-breathing engine can be engineered with valve reliefs as to be NI, the only downsides being very minimal reductions in CR, and a very slight increase in polluton (still handily within limits.)

Unless you mean post-manufacture, yes, then you need to weigh the trade-offs of a hot cam vs. losing NI status.


Thank you, everyone - very helpful


Was the timing belt beyond the specified replacement interval? On a 2005, I suspect that it was. In that case, it’s really not fair to call this a problem and say that the car is unreliable.


Well yes, the timing belt was beyond the replacement interval. You are right about that. I plan to get religion on following recommended maintenance.


When I first saw this I thought the OP was referring to engines that could run inverted i.e with inversion capable oil system and uninterrupted fuel system. Some piston and jet engines have oil systems that will not starve the engine of oil if the airplane is flown inverted for an extended period. The fuel system has to be arranged to provide uninterupted fuel flow in the same situation