Hot Rod Forum banner
1 - 11 of 11 Posts

·
4 chevys and a ford
Joined
·
614 Posts
Discussion Starter · #1 ·
Im curious as to how the variable valve timing works.
I am also interested on any general info on the engine, from people who know this engine well.
Pros and cons?
Thanks in advance
Brian
 

·
4 chevys and a ford
Joined
·
614 Posts
Discussion Starter · #3 ·
Thanks. I love reading stuff like that.
At first it seems pretty technical. Seems aimed at Mercedes Techs. One thing really caught my attention though....
It reads:
"When confronted with complaints of lack of power or performance, which most likely will be accompanied by a MIL (Malfunction Indicator Lamp, also known as the Check Engine Light)
Do you have to tell a Mercedes Tech what the MIL is? Or that is also called the "check engine light" ? That seems odd.
Im thinking about getting an 08. The scariest thing I found was about that timing gear that fails, in the early models.

The whole VVT system is an elaborate hydraulic, electro , computer controlled system, that is a world in itself.
Totally fascinating, and obviously it makes a much more tuned and precise running engine. Probably by a long shot, im guessing .
Will the M273 be a popular engine for car enthusiasts and hotrodders in the future? Will it be around in 20 - 30 years?
Thanks
 

·
Registered
Joined
·
4,263 Posts
I would rather have variable valve lift then variable valve timing. Or a combination of both.

It is like you have 2 diffrent cam profiles. One nice, one naughty. When you add vvt on top of vvl you get a new level of tuning.


Vvt by itself is very old tech and as shown can be failure prone.

Not all engines are equal. Some do things better then others. The thing needs to fit the application. That being said the "good" engines that make the best use of vvl and vvt have been around for a few years.
 

·
4 chevys and a ford
Joined
·
614 Posts
Discussion Starter · #5 ·
I should probably know this, but are there engines with solenoid operated valves? That seems so much more simple than moving cams with hydraulic pressure. It seems like you could have infinitely tuneable valves with computer controlled solenoids. I guess you would need super strong, super fast solenoids.
 

·
Registered
Joined
·
4,276 Posts

·
Registered
Joined
·
4,263 Posts
Yea.
That is currently called freevalve.
The last time I checked a ton of cash and ton of tuning still resulted in problems that placed the idea on a shelf till later.

Here is how VVT and VVL lift work. Now there are variations on the layout/number of solenoids and oil pathways. but it is a good general explanation on how these systems work.


Note that when we are talking about VVT that is mostly to reduce power or reduce emissions when it is not needed.
While VVL is used to increase power(often with a turbo) by changing that profile with some form of sliding of the cam lobe as needed.

The explanation of the different types of VVT used by Honda(who everyone basically copies) below will give a nice understanding on the benefits of the system.


Finally we add Variable Compression to the mix of valve manipulation with different types of injection.

This little puppy has some severe potential. It does a complex thing in a simple way.




This all being said the ICE engine is the flaw here. To have two different modes (power/efficiency) the best way is to have two different "engines". That is why you see electric ICE hybrids. Generally when people think hybrid they think of the IC engine as a means to charge the electric motors battery pack. But that IC engine can also be used to provide power on top of the electric motor when short term high output is required as well as charging when that high power is not needed.

Now, I am for all electric power trains. They are simply better then ICE setups with more potential. But unless you want to lug around a huge battery pack you still need onboard charging station. So we dust off what I consider a very simplistic designed engine the rotary. By using a small rotary engine you can charge a small lightweight battery pack to power a high output AC motor.


The motors have come a long way also. For years people could only dream of using AC motors in cars. It is more a cost, weight, and power demand thing then technical. But the lack of affordable availability of the engines and battery packs had most people hitting a wall. Now these engines are coming out and the new wall is working within the programing and tuning to have the engine work the way you want it to for the application. To my understanding a universal "swap" AC motor that you could grab from your local junkyard and hook up to run standalone with minimal tuning "like you currently can with a LS" is simply not out yet.


Tuning aside charging/storage has been a wall stopping most rides from really making power.

Say hello to high output electric cars little friend.

This reinvented rotary engine will allow for charging to the point that the battery pack can be greatly reduced.
So, what you have is a lighter engine, lighter battery pack, lighter power train, better packaging, and crazy power when you want it while having lower emission and fuel economy then any ICE engine with any kind valve and compression manipulation could ever hope for.

Hopefully I have not strayed off to far in the above post. There have been alot of developments to keep the ICE engine as a prime mover. In some form ICE will always be "under the hood". But at some point it will make sense to use it solely as a means for charging.
 

·
Registered
Joined
·
279 Posts
Looks like Koenigsegg has a camless Freevalve engine in production. Limited production, probably. 600 HP from 2.0 liters, turbochrged.

Freevalve is apparently a sister company of Koenigsegg.

 

·
4 chevys and a ford
Joined
·
614 Posts
Discussion Starter · #9 ·
Looks like Koenigsegg has a camless Freevalve engine in production. Limited production, probably. 600 HP from 2.0 liters, turbochrged.

Freevalve is apparently a sister company of Koenigsegg.

I try to kinda keep up. because im so fascinated by machines, and physics . I had never even heard of a Koenigsegg before a few days ago. Maybe im reaching the age where stuff is moving faster than I can keep up with. I did , however, see the inherent, current, problem with electrically operated valves. Power, speed, and some longevity. Maybe as computers get better, metallurgy will also get better, and super strong little electric motors, and solenoids, will improve more than even thought possible. very cool. Maybe the gas engine of the future, will beat an electric, with efficiency, and power, and torque. maybe? A pint of gas, or a lot of energy used, to produce the energy needed, to plug in the family car. creeping up on the perpetual motion engine (which I do not believe is possible....at least until einstien is proven wrong, and thermodynamics is as old as the idea of heliocentric universe)
 

·
4 chevys and a ford
Joined
·
614 Posts
Discussion Starter · #10 ·
Looks like Koenigsegg has a camless Freevalve engine in production. Limited production, probably. 600 HP from 2.0 liters, turbochrged.

Freevalve is apparently a sister company of Koenigsegg.

Wow.
I wonder if the foer fathers of combustion engines thought about being able to adjust all the parameters of a running engine?
I bet some of them did. Maybe some of them did envision a continuously changing, tuning engine. "what if combustion volume could change, gas delivery and exhausting could be varied, ignition timing could be controlled?"
I bet problems of ignition timing, flame propagation, and piston and combustion speed, etc...seemed insurmountable at the time. Use some springs to keep it going, and thats it. That was ingenious for sure. Someones name should be known. How to time ignition, to keep a combustion engine going!
The leap from there, to electronic ignition, was probably foreseen for a while, but absolutely incredible, none the less.
Could they have imagined an engine that could monitor itself, and change itself based upon that monitoring? Maybe some would see the Koenigsegg as super natural,
and others as " oh... thats how you do it"
 

·
Registered
Joined
·
4,263 Posts
Some of the things we think of as new are far from it.


One of my favorite old engines is a autounion v16.

Single overhead cam driving the valves on the 16 cylinders. Supercharged forcing air in through a throttlebody into one beautiful intake.
The thing is both simplistic and highly servicable.

526704


Image pulled from this great read.
526705



Look at the throttle body.

Fuel injection, timing control, and potentially a variable cam, could quite easily be added to this engine design. Frankly the engine had alot more potential. It was limited by the chassis and (improving) aero which still put out some amazing numbers before it's end.



The freevalve system is overcomplicated and not a true camless setup. It is a electronic assist and control. But, the minior tuning benifits for the reduced reliability is what killed it.

There are better ways currently to control valves or eliminate the valves completly.

Sometimes simple just works.
Adding layer upon layer of frosting on to a horrible tasting cake still leaves you with a horrible tasting cake at the core.
The simpliest way to fix the problem is to toss out that horrible recipe and make a new one with fewer layers of frosting.
 

Attachments

1 - 11 of 11 Posts
This is an older thread, you may not receive a response, and could be reviving an old thread. Please consider creating a new thread.
Top