Zeus

Have you ever even WATCHED F1 before?

There was JUST a big controversy because the slot between the two elements of the Ferrari cars' rear wings was opening and closing based on the speed of the car. People were saying it should be illegal because it does the same thing as a variably controlled wing.

Ferrari's response was that you can only make wings so stiff and it's only natural that it bends.

Hell, even in the Grand Prix of Europe this past weekend there was more talk about it because one of the Renault's front wing was flexing.

Old SStroker

Well back in those days we only had flat lifters, and the edge of the lifter just shaved off the rubber so every time we ran the rubber cam the lift got less and less until it wouldn't even start. Every time we went to the drags we had to install a new cam with the tall rubber lobes. We did great during first round of eliminations, but each succeeding round was slower so we never made it to the finals. We did try cam flanks with very mild (soft?) initial velocity (lift/degree) which then got very aggressive so the lifter would jump off the top of the lobe rather than shave it. It looked sorta like a ski jump. Someone at Comp (I think) later adapted that technique and called it 'lofting'. He probably now designs many of the winning Cup cams.

Finally we decided to just street race for pinks with one run for all the marbles. That was a better deal. Many years later we got some network folks to make a TV show out of racing for pinks. They screwed us out of the idea without paying us much, so now I just hang out on car forums.
.
.
.
.
.
.
.
.
.
.

.
.
.
.
.
.
.
Guys, it's a joke! Don't take me seriously.

Jon B.

iTrader: (5)

Watched the race over the weekend actually. I dont keep up with the news however. If anyone was listening to me, i'm sorry, i'm mildy retarded. I was just reading the rules from the book for 2006. My bad.

Jon

njn63

haha, and in 1998 the Honda community believed the same thing. Then we learned how to tune.

The reason a lot of the higher power Hondas lose the VTEC is oil pressure fluctuation and valvetrain weight. The cars that lose it are pure race cars though and have terrible low end power (worse than before ).

As far as VVT being a joke and not needed, just watch this:
http://www.youtube.com/watch?v=iRQuO66mYxc
I believe that system only controled cam timing and it created noticible gains. You really think a V8 could NOT benefit from that?

note: i hope that's the right video (that shows the Mine's skyline with and without the VVT system). I'm on dialup right now so i can't watch it

Ballistic Jello

Well, I just watched it, and I don't think they talked about variable anything, just how responsive and fast the Mine's car and the Amuse Supra were...

This topic is great, I'm learning a ton.

XxGarbSxX

Actually, anything that would let you spin a motor faster would create the potential for more horsepower. Getting an LSx to hold 400lb.ft. of torqe from say 3k to 9k (about where the R34 was) would be beneficial. Period. Actually doing so is easier said than done, though. It's all in the tune.

LTSpeed

But they don't dictate thickness, direction of grain, or shape. Like Indy cars, F1 cars do have self-modifying wings--front and rear. FIA is not unaware of this.

Third Gear

iTrader: (3)

The only way I think you could give a pushrod engine a secondary cam like VTEC would be if you were able to create a cam lobe made out of multiple pieces and create some device that would make the lobe "grow" in relation to the base lobe slightly thereby giving it additional lift and duration. I just can't think of how to activate the secondary mode... maybe by centrifugal force or something?

I still like the thought of running a stock cam up until 4500 RPM and afterwards running something ridiculous like a Trex up until redline. But it just adds complications, costs, and more difficulty tuning.

These engine do so well with heads/cam or boost we really don't need any of those cool little tricks.

cantdrv65

iTrader: (3)

Hmmm. Why have to push or pull a valve at all. Let the solenoid and valve become ONE assembly (integrated in the head), like an industrial solenoid valve. Im sure a cooling system could be made for the valve actuator. I think you have to think outside the box, and redesign the head.

MrDude_1

iTrader: (4)

one of the problems i have with all modern engines, is the design of the valve.

why in the world do you want a valve that obstructs the airflow when "open"?? if you could design some kind of valve thats fully open, and seals properly, takes the heat, miles, ect..... then you would have a massive increase in efficiency, power, ect... and while you're at it, it could be designed to be controlled with a variable timing system from the start...




of course, theres alot of obstacles to overcome...namely a valve design that works and lasts..... and thats why we're not all doing it at the moment.

joecar

I agree with you both...

But to get something going asap with minimal changes requires keeping the good-known-working aspects and avoiding major design changes (for now)...

the one advantage of the current valve shape (that has made it successful for 100 years) is that combustion pressure pushes on the valve helping it to seal.

XxGarbSxX

Here's an idea I came up with, minimal changes. Simply put the valve on a hinge and use a rod to push it open.

Another Idea would be to make the valves themselves the throttle bodies. It would be prettymuch the same thing as ITB but instead, the valves themselves would be the t/b. Of coarse, that would be rediculously complicated, if not impossible. With how fast the plates will be opening and closing, you'd probably see some flex in the plate after a few hundred miles. I think my hinged valves are a much better idea.

Old SStroker

Actually, the poppet valve, as used for over 100 years doesn't really obstruct the flow once it gets open about 1/4+ of the valve dameter. The shape of the port, valve seat and valve itself helps direct the flow into the cylinder.

You might do some more research on this. Smokey Yunick discussed it 20+ years ago, David Vizard has some good info on it also.

Try this link:

http://speedtalk.com/forum/viewtopic.php?t=757

You might also look deeper into the "Coanda effect".

DavidNJ

http://jnaudin.free.fr/html/coanda.htm

Third Gear

iTrader: (3)

This is the **** right here...

http://www.coatesengine.com/index.html

MadBill

Leaving aside the rotary and solenoid valve exotica, it would not be that difficult to achieve a VVL function on a pushrod engine. Starting with a hydraulic roller LSX for example, one could use a double wall lifter with the inner roller element operating off a central cam lobe. It would be flanked by a pair of high lift, high RPM lobes upon which would ride a cylindrical flat tappet-style sleeve. As in OHC VVL systems, at low RPM this would ride freely on the lobes, held in contact by a light 'rev kit' type spring. For high RPM use (also as per OHC practice) an ECM-controlled, hydraulically-activated pin would lock the sleeve to the central lifter, thus transmitting the aggressive lobe profile motion through the inner element to the pushrod.
It would be possible to reverse the lobes to enable the roller element to operate on the high speed lobe, but I suspect an OEM application would choose to garner the fuel economy benefit of the low friction roller in the low speed mode.

rocketrider93

oh man what a crazy idea that was sick. i wonder when they will start making retrofit kits for old v8's i wonder if they will ever do it for old pontiac v8s

drivefastgto

I can't possibly see how any sort of multi-profile lobe could ever work out in the long run. You could never have enough contact surface between the lifter and lobe for any sort of durability unless the engine was 4 feet long. I would be shocked to see any kind of VTEC, etc. on a pushrod engine.

However, the concept of retro-fitting an electric/pneumatic valvetrain would be the greatest thing since overhead valves. The tuning possibilities of an infinitely adjustable valvetrain would be limitless. I read a magazine article a few years ago (Hot Rod?) about how Siemens was developing something like this. I never heard any more about it though. Somebody's gotta do this...

EdmontonSS

Multi-lobe, no, but a "variable" lobe is easy. The lifter in your LS1 doesn't rotate, nor does the roller on the lifter need to have a flat profile, nor the cam lobe itself. Like mentioned above, Ferarri already does this. A system like the Ferrari system would be very easy to incorporate into a OHV V8.

cantdrv65

iTrader: (3)

Solenoid/air/hydraulic valves cant be that far off from being developed in street engine. A ton of extreme duty and very reliable designs are already in service in different industries. Yes, it will change the game.