Ever read something cool in an article way back when and then later can't find the article in your stacks of car magazines ?

Months back I read about some new roller lifter design that used plastics (or some other super light weight material) for major weight reduction on a roller valve train. I've been searching for the article for hours and still can't find it !

Has anyone else heard/read about these lightweight roller lifters ?

thx in advance,
RP.

 

Plastic I haven't heard...

BUT

I have heard that alot of companies have succesfully done testing with ceramic valve train components. They are much lighter compared to traditional steel versions thus helping minimize the pumping loss from a poppet valve system.

As far as advances in valve train technology this is not big news.... look up "camless engine" if you have a few hours to spare... or pay coatesengine.com a visit.

 

For those who don't have 2 hours to blow:

Where the CSRV really shines is in its airflow potential compared to a poppet valve Bench-marking a 5.0 L engine from a Lincoln, the stock Ford casting (when tested at 28 inches of H2O) flowed approximately 180 cfm on the intake port at static. The rotary valve for the engine in comparison flowed a whopping 319-cfm at the same test pressure. Equipped with the poppet valve head, the Lincoln engine dynoed at 260 hp and 249 lb.-ft of torque. When equipped with the CSRV head at the same 5,500 rpm test protocol, it made 475 hp and 454 lb.-ft of torque, with no changes to the block or rotating assembly: The higher power was a result of diminished frictional and pumping losses, but the inherent airflow benefit of the spherical valve was the major contributor. With a conventional poppet valve, it can take 34 degrees of crankshaft rotation or more to reach a fully open position, wasting energy and limiting volumetric efficiency. With the CSRV, a comparable port area is exposed in only 2 degrees of crank rotation. The CSRV allows for superior surface flow coefficients from its spherical shape. With the standard 4-inch Ford bore, the factory poppet valve covers only 15.8 percent of the total bore area, while the rotary valve is measured at 20.5 percent.

The design of the CSRV, which at first glance resembles an OHC cylinder head, allows for the central placement of the spark plug in the bore. By varying the spark plug location when referenced to the bore centerline, the most desirable position is in the center. This will allow the cylinder pressure build in the minimum amount of crank rotational degrees past TDC.

Since horsepower is defined as work over time, the CSRV allows for an extremely high rpm potential. Test run at Coates' facility have seen a Ford 5.0 liter engine spin to 14,750 rpm! Though the CSRV removes the valvetrain rpm limitations, the need to have a rotating assembly that can withstand the engine speed becomes the essential element. Another benefit of this design is the extended oil change intervals, with the lubricating system not being exposed to the rigors and pollution from the poppet valve.


http://www.coatesengine.com/eGallery...erformance.htm

****Clif's Notes **********************************
Camless engines have the potential to be wicked fast
***********************************************

 

Whats the downside? Theres always a downside... Im sure its pricey as pricey can be but anything else?
greg

 

The downside is that alot of people don't believe George Coates solved the sealing problem. Many people believe that the cerami-carbon berrings wear quickly. As for cost, it's actually cheaper to build the coates engine than a traditional valve-train.

As far as racing goes... the cerami-carbon berrings will definitely last a race... Coates recently signed a contract to build an engine for McLarren.

There are other alternative valve systems... one of the cooler ones is EMV - Electro Mechanical Valves. The camshaft is eliminated... and the valves are fired by noids with computer generated signal.. much like EFI. EMV is only good to 6,000 RPM as of now.... but is already being mass produced on ford diesels starting next year.

 

This is coming out next year? I read about it in a mag and they were calling it a concept idea that might be out in 10 or so years... They were also talking about upping the system to 48 volts to support the added solenoids for the valves and such. Sounded pretty good but I am sure they made it sound like a thing of the distant future. Imagine the tunability if it was put on a performance engine :lala:
greg

 

Oh and btw good job on the new av!
That old guy was really starting to creep me out...
greg

 

http://www.findarticles.com/cf_0/m30.../article.jhtml

This article is pretty old... but it says that Fords will be getting camless in 2003. It also says that ALL Navistars will be camless by 2007.

I came across another article where a frickin kid built an EMV engine to run his RC boat... he's got it up to 1,200 RPM.

 

I read about EMV's a while ago and thought about what you could do to a modern fuel injected turbo motor utilizing distributorless ignition:

Without getting a spec of dirt on you could:

change your cam, whatever cam you want, whether it exists or not!

"re-curve" your "distributor"

raise/lower boost levels

modify fuel curve ("change jets")

It's really amazing to think that before too long you could probably buy a new car, PLUG IN a user programable engine management system, and dial in an extra 100 hp, without even breaking a sweat, and think of the trial and error you could do..(add a few thou. of lift, tighten up lobe separation angle a couple degrees, ahhhh, a few more degrees of duration.. that should do it )

Tools?? who needs em' :lala:

 

Problems with EMV systems:

1) solenoids do have "delay times" to retract- so what would have formerly been known as cam timing is still limited on an EMV system

2) solenoids may get weaker over time which would likely start to display itself as erratic engine operation- but not as audible "noise"- so when a failure hits it is more than likely that your average car owner won't notice until engine is running on less than all cylinders- and quite possibly loading up fuel in the intake system as one 'valve' won't open- or, worse- backfiring through intake system if it's an exhaust valve solenoid that fails or becomes disconnected.

#2 is the most relevant to us lowly car owners- how much damage can be incurred to the engine/intake system overall in the case of a defective or disconnected solenoid? Is it engine rebuild time everytime a solenoid craps out and takes something else with it? This surely must sound great to dealer service departments- but not to me, a consumer without an unlimited budget for engine work.