I did a bit of reading on this a few years ago,but boy does it make for a complicated and busy camshaft

[Wild one]

Here's the WORLD'S FIRST CVVD Engine! | Here's the WORLD'S FIRST CVVD Engine! | By Engineering Explained | Facebook

Here's the WORLD'S FIRST CVVD Engine!

www.facebook.com

 

[Jwithing]

Very interesting. Time will tell for that one, but I wonder how long until we start seeing it in more performance oriented applications. I want to see the fancy Lego cam blow apart lol.

 

[savage_46]

This is why I want to see combustion engines live on & be further developed. There's so much untapped potential out there for efficiency & emissions to be improved upon. Unfortunately, as it seems right now, EPA & CAFE are gonna win and eventually imposing fines (my guess) on combustion engines soon(ish). Just like the gas guzzler tax now. Where everything is currently at, I think Freevalve is the best possible option....infinitely variable.

I'm too young for it, but who grew up with carburetors? They were the standard for 100 years. 2 barrel, 4 barrel, tri power,.... They were improved upon for efficiency & performance. Then TBI came out & was easy to adapt to the current engines. Seems like within 10 years after that, carbs were obsolete. Then the switch to MPI, and then SMPI. Add in VVT & VVL depending on the engine, DOHC becoming common place, V6 that can keep up with a V8 from 10 years ago. Pardon the pun, but advancing valve timing tech is the next step to keeping engines alive

 

[Wild one]

This is why I want to see combustion engines live on & be further developed. There's so much untapped potential out there for efficiency & emissions to be improved upon. Unfortunately, as it seems right now, EPA & CAFE are gonna win and eventually imposing fines (my guess) on combustion engines soon(ish). Just like the gas guzzler tax now. Where everything is currently at, I think Freevalve is the best possible option....infinitely variable.

I'm too young for it, but who grew up with carburetors? They were the standard for 100 years. 2 barrel, 4 barrel, tri power,.... They were improved upon for efficiency & performance. Then TBI came out & was easy to adapt to the current engines. Seems like within 10 years after that, carbs were obsolete. Then the switch to MPI, and then SMPI. Add in VVT & VVL depending on the engine, DOHC becoming common place, V6 that can keep up with a V8 from 10 years ago. Pardon the pun, but advancing valve timing tech is the next step to keeping engines alive

I'm waiting for them to start spending more time developing a variable compression ratio cylinder to.I agree there's still more in the internal combustion engine,but with the push for electric,i wonder if we will see much more in the way of gasoline engine development

 

[savage_46]

I'm waiting for them to start spending more time developing a variable compression ratio cylinder to.I agree there's still more in the internal combustion engine,but with the push for electric,i wonder if we will see much more in the way of gasoline engine development

I think it was Mazda that had a prototype engine a few years ago that could run on gas & diesel, auto switch between the two just like a E85 setup. Haven't heard anything on it since it was shown (don't remember if running). Can't remember if it was SEMA or one of the big auto shows.

To me, it would seem that a variable compression engine could be done with a VVL valve train. Probably leave exhaust valve open on the start of the compression stroke. But also need a fail safe down to low compression mode for limp in or system failure. The same way a 3.6 pentastar oil pump fail safes to high pressure if there's an issue. It would be interesting though

 

[RacerRon]

Technically , throttle valve controlled engines are variable compression. The dynamic compression is very low when not at wide open throttle because the cylinder is not filled. This is the idea behind EGR valves. It helps volumetric efficiency by adding post combustion glasses to the poorly filled cylinder. Variable valve timing would be the best way to control cylinder pressure and allow a higher static compression starting point. This is where the diesel efficiency advantage is in that the cylinder is always full of air and only enough fuel is injected for the needed output. They always run at %100 VE or greater if boosted.

 

[HEMIMANN]

Whatever happened to solenoid valves? Trade Rags used to yap about that on occasion.

They made it work on multiple injection diesel fuel injectors - breathing valves still too much mass compared to injector pintles?

 

[Docwagon1776]

This is why I want to see combustion engines live on & be further developed. There's so much untapped potential out there for efficiency & emissions to be improved upon. Unfortunately, as it seems right now, EPA & CAFE are gonna win and eventually imposing fines (my guess) on combustion engines soon(ish). Just like the gas guzzler tax now. Where everything is currently at, I think Freevalve is the best possible option....infinitely variable.

I'm too young for it, but who grew up with carburetors? They were the standard for 100 years. 2 barrel, 4 barrel, tri power,.... They were improved upon for efficiency & performance. Then TBI came out & was easy to adapt to the current engines. Seems like within 10 years after that, carbs were obsolete. Then the switch to MPI, and then SMPI. Add in VVT & VVL depending on the engine, DOHC becoming common place, V6 that can keep up with a V8 from 10 years ago. Pardon the pun, but advancing valve timing tech is the next step to keeping engines alive

Of course, EPA and CAFE were major driving forces behind those tech advancements. Chevy had tried fuel injection decades before it went mainstream with limited to no interest. Even now you see guys driving new trucks with new tech getting a bajillion horsepower with unheard of fuel economy and pretending to want to be driving an 'old simple truck'. They are lying, either to themselves or us, because if they *actually* wanted to they would be. Those old simple trucks didn't disappear and buying one and completely refurbing it is still cheaper than buying a new one. But the appeal of nostalgia for whatever 'simpler times' they remember as well as the inertia of the status quo makes adapting to new technology very hit or miss regardless of the merits of the new technology. That's not to say all new tech is good, mind you.

While there's doubtlessly still efficiency to be found in ICE motors, the issue of energy wasted as heat will always mean overall efficiency is low. Diesels may approach 1/2 of the energy in the fuel being converted to mechanical energy, gas does is closer to 1/3. Absent some technology that subverts are current understanding of thermodynamics that's not likely to change substantially.