interference versus noninterference engine??

I guess it's non-interference but I'm not sure if it's applicable since the Prime and all Prii don't have a timing belt or chain (or any real transmission just a torque converter, unrelated to timing).

If you're worried about powertrain lifespan don't be; it lasts longer than almost all vehicles.

EDIT: My mistake all Prii including the Prime have a timing chain for the ICE. See other better informed responses...

Posted via the PriusChat mobile app.

 

Prius uses a chain instead. So, concerns related to a belt don't apply.

 

All Prius years and model variations have timing chain.

#1 in Easley,SC

 

there is a timing chain under a cover on the engine. i don't recall ever hearing about one breaking, but i suppose they stretch a bit after very high mileage.
a bigger issue has been a leaking cover on some models, which requires a lot of disassembly to repair.

 

Here are several pics of the timing chain and the 1.8L engine internals on the Gen3 motor:

Blown Head gasket rebuild....@297k

Peruse at your leisure this thread as it has good documentation and discussion around the 1.8L engine.

Enjoy the light weekend reading .

 

Very few reported claims of the timing chain breaking or failing. There have been many Prii that have eclipsed 300 k miles without issue with the chain. In a Prime, the engine should be running less (depending on your use) so less risk of damage.

If the chain were to fail, I would assume some damage would occur. But in the 20+ years of driving I have logged in various different makes and models, I have not dealt with that issue.

 

Here's a recent thread on the topic with a link to another thread on the same topic:

Timing cover leak

More light weekend reading .

 

I think most new engines are interfering because of close tolerances and high compression.

#1 in Easley,SC

 

It is still a valid question but your use of the term "free running" sounds like you don't really know what the concern IS.

With over head valves OHV, if the valves are still full open when the piston reaches top dead center TDC, the valves can hit the top of the piston unless the clearances are designed to prevent that.

Anything that throws the valve timing WAY off can cause the collision in an "interference" design.

 

This link might answer your question.

Interference Engines - The Complete List - Your Car Angel - Your Car Angel

#1 in Easley,SC

 

Just for novices not conversant with the terminology: saying an engine is "interference" means if the camshaft rotations are not properly synchronized with the crankshaft, that both are allowed to turn freely and independently (due to absence/breakage/misalignment of timing belt or chain between the two shafts), then it is possible for the pistons to hit the valves.

 

Gates is the primary supplier of automotive belts in the US. They used to have a means of searching for a specific car to tell you whether or not it had a timing belt, and if so if it was an interference engine, but I can't tell from my phone. You may want to search here:

Timing Belt System Products | Gates Corporation