Interetsing new Engine Technology - Fiats new Electro Hydraulic Valve System

Very cool in my opinion. I understand the %ages quoted are almost meaningless.. but if I understand correctly.. you can run the wildest (or close to) cam profile ever and have complete drivability (or considerably improved) throughout the entire rpm range.

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Andrew M
Onterrible
30ish

Caterpillar has had variable valve timing since '04 they call it "ACERT Technology". And yes, it's way cool to be able to program valve timing with a laptop computer.

-Tim

Tim Taylor Wrote:
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> Caterpillar has had variable valve timing since
> '04 they call it "ACERT Technology". And yes,
> it's way cool to be able to program valve timing
> with a laptop computer.
>
> -Tim

I knew that you could take new cat engines and just "magically" dial in the HP you wanted.. but I guess I hadn't taken the thought step as to why.

It seems like we're not far off from having really really fun engines that you can live with everyday.

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Andrew M
Onterrible
30ish

http://hubpages.com/hub/how-does-the-MULTIAIR-fiat-works

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Andrew M
Onterrible
30ish

hudson Wrote:
-------------------------------------------------------
> Tim Taylor Wrote:
> --------------------------------------------------
> -----
> > Caterpillar has had variable valve timing
> since
> > '04 they call it "ACERT Technology". And
> yes,
> > it's way cool to be able to program valve
> timing
> > with a laptop computer.
> >
> > -Tim
>
> I knew that you could take new cat engines and
> just "magically" dial in the HP you wanted.. but I
> guess I hadn't taken the thought step as to why.
>
> It seems like we're not far off from having really
> really fun engines that you can live with
> everyday.
>
>
>
> Andrew McNally
> Hamilton, ON
> 29


Cool as it is it didn't work out to well for Cat. ACERT didn't make the cut for 2010 emissions and they are pulling out of the truck engine market altogether. No Cat engines in big rigs no more.
http://www.truckflix.com/news_article.php?newsid=5750

Most large diesel engines come in multiple HP/torque ratings and it is all done with engine management and has nothing to do with variable valve timing.

Fiat stuff looks cool. When will it show up in Chryslers I wonder.

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Quote
Morison
[jvl] Ohh noooohs! There's an h'off tawpik thread in the gent-urinal dick-cushion four-hum. THINK OF THE CHILDREN!!![/jvl]

RallyTaco Wrote:
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> Cool as it is it didn't work out to well for Cat.
> ACERT didn't make the cut for 2010 emissions and
> they are pulling out of the truck engine market
> altogether. No Cat engines in big rigs no more.
>
>
> Most large diesel engines come in multiple
> HP/torque ratings and it is all done with engine
> management and has nothing to do with variable
> valve timing.
>
> Fiat stuff looks cool. When will it show up in
> Chryslers I wonder.

To be honest I don't follow big truck motors at all. That's interesting that they can make the emissions cut.

There is already talk of the Fiat system showing up in Chrysler vehicles very soon.

Which excites me because I want to mess around with it.. I figure it won't be impossible to retrofit it to any DOHC head. There will be problems with the system I'm sure.. but the thought of having a no compromise bump stick is pretty exciting.

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Andrew M
Onterrible
30ish

tuning this would be a lot of fun, especially if it was on an interference motor! yikes.

brianallmotor Wrote:
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> tuning this would be a lot of fun, especially if
> it was on an interference motor! yikes.

I think you're being a bit paranoid To tune it you would input your max "safe" intake lift, duration etc and then tune it down for lower rpms.. You certainly wouldn't start off with the intake valve being open all the time

I get your point though.. if something went wonky you could have a valve open at a costly and unfortunate time.

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Andrew M
Onterrible
30ish

It looks like there is a max cam profile that is still defined by the cam. Then you are giving it a % to open or you can do 2 stage openings. When you give wide open throttle it will run off the full cam profile. You can't go beyond that and keep a valve open 100% of the time.

This is more for low-rpm and part throttle tuning and more a variable VTEC, instead of an on/off low/high rpm cam profile you have an infinite variable cam profile to driving situations. That way you can have crazy race cams and get an OEM like idle because you dial back the cam profile.

BillyElliot Wrote:
-------------------------------------------------------
> It looks like there is a max cam profile that is
> still defined by the cam. Then you are giving it
> a % to open or you can do 2 stage openings. When
> you give wide open throttle it will run off the
> full cam profile. You can't go beyond that and
> keep a valve open 100% of the time.
>
> This is more for low-rpm and part throttle tuning
> and more a variable VTEC, instead of an on/off
> low/high rpm cam profile you have an infinite
> variable cam profile to driving situations. That
> way you can have crazy race cams and get an OEM
> like idle because you dial back the cam profile.

Yeah that's what I'm saying.. or was trying to say.

You figure out just how wild of a cam your engine can handle.. and then you dial back for part throttle, idle etc.. and when you're done you've made a pretty killer power band I'd imagine.

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Andrew M
Onterrible
30ish

with that sort of design, a failure case comes to mind where you just lose the ability to subtract lift/duration, and you'd be back on the full cam all the time, so no blown motor hypothetically during a "fancy valve-system thing" failure.

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------------------------------------

http://www.ckrally.com

cblakely Wrote:
-------------------------------------------------------
> with that sort of design, a failure case comes to
> mind where you just lose the ability to subtract
> lift/duration, and you'd be back on the full cam
> all the time, so no blown motor hypothetically
> during a "fancy valve-system thing" failure.
>
>
>
> ------------------------------------
>
>

That or it stays subtracted.

I don't know how the system accounts for hydraulic oil temp either.. but frankly does it really matter that much? Maybe just tune it for hot oil and get on with your life.

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Andrew M
Onterrible
30ish

Hm, there is really no reason for the cam to be in the head, a pump that is timed with the crank could provide pulses of oil pressure that could be directed to open valves or return to the reservor. Got to move that oil quickly, both in and out of the slave piston.

Derek

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In the long run reality always wins.

derek Wrote:
-------------------------------------------------------
> Hm, there is really no reason for the cam to be in
> the head, a pump that is timed with the crank
> could provide pulses of oil pressure that could be
> directed to open valves or return to the reservor.
> Got to move that oil quickly, both in and out of
> the slave piston.
>
> Derek

A remote cam is just going to add compliance and fluid friction drag-->more heat to the system. It will consume much more energy than a mechanical camshaft. Full servo-hydraulic valve timing has been done before too. It was only on a test engine though because the Moog servo valves cost about $2K each and it took one per valve.

-Tim

F1 does away with valve springs in favor or pneumatic valve return to alleviate float at 19,000 and reduce drag.

Siemens and others have developed electromechanical systems available that do away with cams altogether. Solenoid or electrohydraulic systems seem way more logical to me. Program the rise and fall and ditch the cams completely.

In fact, while we're at it, if you have new ways of opening valves, I think we could rethink the valves themselves, too!

The IC piston engine is the most polished turd that man has ever developed. More man hours have been spent on how to make this (inefficient by concept) linear motion to rotary motion converter more powerful and efficient than any other engineering endeavor in the history of mankind.

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Lurch
Eric Burmeister
The west coast...of Michigan