This Is Ruining Engines - The Consequences of Low Tension Piston Rings

Support the channel by shopping through this link: https://amzn.to/4hdUdlc
Become a Tuning Pro: https://hpcdmy.co/dr4a
Patreon:   / d4a  
Become a member:    / @d4a  

Three boxes of pistons frings from three different toyota engineers from three different eras. 80 and 90s, 2000s and 2015 until today. The Toyota 2E engine, the Toyota 3zz-fe engine and finally the Toyota 2zr-fxe engine. We will test them all to learn how piston ring rigidity or tension has been reduced over time and how it relates to modern engines burning oil.

To do this I built a little home-made ring tester out of scrap wood that allows me to lock a piston ring in a vice and test the tension or rigidity of the piston ring by placing weights on top of it. The tension of a piston rings is directly related to the friction inside the engine. The more tension there is in a piston ring the more pressure the ring will apply against the cylinder. The more pressure there is the greater the friction. This means that reducing piston ring testion improves efficiency. But there's a price to be paid and the price is in sealing.

As you will see in the video, in the 2000s a compromise was found. Compared to the 2e engine which has high tension on both the first and second compression ring the 3zz-fe engine has high tension on the first and low tension on the second ring. A compromise between sealing and efficiency that leaves a decent margin for error. On the other hand the 2zr fxe engine has low tension on both the first and second compression ring as well as a completely redesigned control ring pack which is extremely low tension. Such a setup can work but it's reliability is questionable in the real world because there is virtually no margin for error here and nothing to stand against the great number of variables in real world usage scenarios - different environments and different users. On top of this retaining perfectly consistent machining over hundreds of thousands of engines is impossible and low-tension rings demand exactly this in order to not burn oil.

The result of this approach of lowering tension to meet ever more stringent emissions standards is of course that nowadays many engines burn oil and manufacturers are claiming in user manuals that this is acctable and that anything up to 1 liter per 1000 kilometers is ok. Recently this too has been rephreased and most manuals say that the vehicle "will burn a certain amount of oil". The reality is that we millions of cars on the roads that now burn 4,5 or even more liters of oil between service intervals. Might as well bring back two strokes. I believe that this is a direct consequence of modern emissions tests such as EPA and WLPT tests completely ignoring engine wear and durability and using only fresh, just broken in engines for testing. I believe that the tests should be carried out on two engines. One new and another one artificially aged to a certain number of kilometers/miles and there must be an allowable maximum difference in emissions, fuel consumption and power between the two engines. If his maximum difference is overstepped the engine should not be allowed on the market. As it is now, emissions testing behaves as though engines do not get used at all and are replaced every couple of hours.


A special thank you to my patrons:
Daniel
Zwoa Meda Beda
valqk
Toma Marini
Cole Philips
Allan Mackay
RePeteAndMe
Sam Lutfi
Cakeskull

#d4a