Anyone ever heard of or seen this product at .v-tech for v8's . Variable Valve Actuation for your pushrod engine sounds kinda interesting yet some how lame to me.



figured some of you might wanna read up, pretty interesting stuff

 

It certainly does look trick, but the advertised hp gains don't justify the expense for me personally. I guess if you were in competition then every gain - no matter how minute - counts.

By the way Un4givn - NICE NEW RIDE - If I didn't tell you already.

 

the VTEC concept is really only useful on smaller ci motors..liek hondas. V8's have no need for such a system....even if it did exist. We have rhodes lifters...but there are alot of horror stories about those.

 

I posted that link a while back, along with the rotary valve site. I think we're all waiting for someone to volunteer and test the durabiltiy and performance over a long time. The theory is sound, but Detroit is finding other solutions to a similar end.

 

Wow.. I went to teh website. Never knew they made such a thing for SBC's. That is very very cool, but it cost $995.00 + $30.00 handling. Now with that money your could make more hp then this can i assume. Will this thing break after a few 1000 miles?

 

We don't need V-Tec!!!! You gotta to be joking.

 

VTEC is varible timing and lift, this is only variable lift. In a Honda, basically there are two cam profiles on one stick, with two rockers for each valve, and it switches between the two to be in the optimum powerband.

I think this would be awesome for a SBC. You wouldn't have to worry about the powerband of the cam, it could make power from idle to 8000rpm, instead of dealing with an unstreetable car if you want to make power up high.

That said, where do the other pushrods, lifters and rockers go in a SBC?

 

Well the point is its only lift that varies. I have long thought of a system for variable duration (no not the lifters) and wondering if they would ever make such a thing. THAT to ME is whats important. My 355 could sit at a light with a stock stall converter and be @ 200 Duration @ .050 lift, then i step on it, experience the thrill of a torquer camshaft, pulling all the way up to its REDLINE @ 3500 RPMS then suddenly, WALAA the duration snaps to 244 @ .050 and i Experience all the thrill of a high-end drag race camshaft, pulling stright up to my new redline at 6500 RPMS all the while pulling like crazy and actually getting good gas mileage around town, not to mention the SLEEPER it would make my car into, and all the fact i can use a stock-stall making it a perfect daily driver / drag race car. A quality bottom and an a small blower on 7 PSI of boost should put me... oh say... 520 Ft.Lbs of torque around 1200 RPMS and, well, should carry me all the way to 680 Ft.Lbs of torque to my redline at 6500 RPMS. Horsepower too, imagine the gains! <- /rant ->

 

There are a lot of patents for variable timing chains like 6,289,860 - but no one has brought em to market

most of the simple mechanical types (no hydraulics or electricity) retard the cam with rpm increase -

I'll volunteer to do the R&D if I could get my hands on one

click here and type in the patent number
http://www.uspto.gov/patft/index.html

 

What about the solenoid controlled valves a couple of manufactures are trying out?

 

I think the biggest problem is the fact ANYTHING other than a Standard pushrod V8 style setup is going to be very COSTLY, Time Consuming, and probably no one would be willing to switch over, it would probably require lots of block work and all kinds of crap. DOING it isnt the problem, its making the swap EASY, QUICK, and AFFORDABLE thats holding everyone back. NO one wants to rip their engine apart to get $400.00 in block machine work done so they can use hydroulic valve setup which cost them $2200.00 to begin with. Not for the street anyways.

 

F VTEC.....valves operated buy solnoids(my father deisgned a concept like this when he was 14.....ahhhboring school days). Lets 1 cam, 2 cams....or infinity cams??? hummm hook the valves up to the computer and the dur and lift can be controled indefitly and can change for get small rpm increase...eliminating the cam from limiting the RPM powerband..... You could have setting ont he computer......1) Best MPG 2) Towing(not us...trucks) 3) Mild street 3) Performance 4) ***** TO THE WALL and of couse number 5 for the shows....SOUND....ohhhh ***, could you imagine how cool you could make a SBC sound......

 

I personally think the solinoid actuated valves would be really cool. Especially if the change between cam profiles was made smoothly and automaticly. The only block mods should be altering the oil flow passages. The cam oil passages should be blocked and oil rerouted to the heads. Then all the changes would be in the heads. If it could be done for a reasonable price, I'd be in. Reasonable for me is 3 grand, tops. I think Indy cars are experimenting with those things, and I heard those engines run at 10,000 rpm sometimes.

 

I can't remember if it's Porshce, Mercedes or BMW, I think its's BMW, is developing an electronic valve.
You don't need to worry about cam profiles, cause you wouldn't have a cam. The computer monitors the throttle position, rpm, engine load, and adjusts lift and duration accordingly. Max torque at low RPM, max HP at High RPM and max economy cruising. Of course there has to be a switch for 'Woodward' mode, where it pops and crackles like a Winston Cup car. Couple all of this with adjustable intake runners (BMW), throttle-by-wire (C5 'Vette), and adjustable flow mufflers (Nissan), and you have a car that is a quiet, mild mannered daily driver (won't scare the neighbors), but nail the gas, and WHOA, MOMMA!

 

What about a device that would the push the lifter retainers towards and away from the cam lobes? Your economy cam profile would be the say the "tip" (not literally but you get the idea) of the cam lobe for just driving. This would occur by pushing the lifters away from the cam lobes a little so they only touch that part. WHen you mash on it, it lower the lifters so they could go over the whole cam lobe, which would be very agressive, for racing and such. The problem here would be that the valves would be somewhat open and out of adjustment when the lifters are raised up in "economy" mode. What i was thinking of was clutched lifters. There would be a special system to evacuate all the oil from the hydraulic lifters to compensate (lifters can't lift they don't have oil in them, at least the hydraulic ones) for how far they are raised. After this point a magnetic clutch takes over (turned on and off according to which profile is being used) to lock the lifter together at a certain point so they keep the valves closed when they're supposed to, essentially making it a shorter solid lifter in economy mode. When its time to race, the magnetic clutch is disengaged and the lifters are filled with oil as they are lowered back down on the cam. The cam profile would definately have to be "unique". Cheap? No, but none of this stuff is going to cheap anyway you cut it.

Just my .02.

 

...and whatever happend to the rotary valve idea?

 

What Rotory Valves?