Corvette & SBC: The King is Dead, Long Live the King

[Tom and Vipers]

LS1/6 Gen III will be replaced by 3-valve variable cam Gen IV.

"...Corvette engine will rev to 7000 rpm with a 30% margin of safety. It can go to 8000 rpm safely..."

"The 6.3-L version of the engine will produce 500 hp..."


http://www.sae.org/automag/techbriefs/09-2003/1-111-9-26.pdf

Multi valve will lay to rest all previous 2-valve designs. (not to mention variable cam timing.)

 

[monnieh]

Torque is what it's all about. 8.+ Liters beats 6.+ anyday.

 

[Craig 201 MPH]

Just more stuff to break. Let them have it.

 

[Vic]

Scroll down that article, and there is a piece on Lotus' camless engine. Proven Formula 1 technology.

You can do more with electronic valve control than you can with various cam grinds. Infinitely variable, constantly adjusting timing, lift, and duration on demand for conditions, maintains torque better throughout the rpm band. More power out of the same amount of gas, and more power out of the same displacement, means lighter engines, hence faster sportscars. Less moving parts, virtualy no valve train inertia, except for the valves themselves. Quick, high and free revving, less parasitic losses. Longer oil life, less friction and heat.

All a cam is is an information sequencer, telling the valves when, how far and how long to open. This method is as antiquated as a mechanical adding machine, verses a calculator.

 

[Vic]

Just more stuff to break. Let them have it.

Thats what my dad said when electronic fuel injection and electronic ignition started to become common place. Now he can't remember the last time he jetted a carb, set the idle speed, adjusted timing advance and dwell, changed points and condenser. Fact is, nowadays, no one has to do those things anymore. Technology has gotten better in this area. Early elec ignition used to crap out very often, but its a rare thing now.

Gotta change with the times, man!

 

[riverflyer]

Scroll down that article, and there is a piece on Lotus' camless engine. Proven Formula 1 technology.

You can do more with electronic valve control than you can with various cam grinds. Infinitely variable, constantly adjusting timing, lift, and duration on demand for conditions, maintains torque better throughout the rpm band. More power out of the same amount of gas, and more power out of the same displacement, means lighter engines, hence faster sportscars. Less moving parts, virtualy no valve train inertia, except for the valves themselves. Quick, high and free revving, less parasitic losses. Longer oil life, less friction and heat.

All a cam is is an information sequencer, telling the valves when, how far and how long to open. This method is as antiquated as a mechanical adding machine, verses a calculator.

Vic, good post and well presented. You should offer a mechanics primer for all of us "mechanically challenged" enthusiasts!! If its made out of wood, I can see, build or modify it but engines are still not as clear in my mind and I appreciate posts like yours that help me understand things in a different light. thanks, John

 

[JGK95]

WOW!! That Definately makes for better competition between the Vette and Viper! The WInner: US!! (and unfortunately the parking lot racer RED5 as well)

Jay K.

 

[DEVILDOG]

Just more stuff to break. Let them have it.

Thats what my dad said when electronic fuel injection and electronic ignition started to become common place. Now he can't remember the last time he jetted a carb, set the idle speed, adjusted timing advance and dwell, changed points and condenser. Fact is, nowadays, no one has to do those things anymore. Technology has gotten better in this area. Early elec ignition used to crap out very often, but its a rare thing now.

Gotta change with the times, man!

That's fine...I'll wait until all the bugs are out after applied to production cars. As far as proven in F1...yeah they run for 2 hours (if they don't blow up) and then they have to rebuild them or throw them away. As far as the new C6 engine I'm not worried about it...TQ rules. Besides it will probably prove to be just as reliable as the BMW M3 engine.

 

[Vic]

Yeah, DD, I always wait until its been out for a while, too. I don't wanna be the first-model-year test-dummy either.

 

[Torquemonster]

The Vette 3 valve with variable cam timing is 80% of a good thing. 4 Valves offers huge gains, adding just 3 is simply another cost cutting method that you won't see in a Japanese performance engine, any European exotic or anything else worthy of mention. It's like buying a home made apple pie that has a slice cut out of it already.

The variable cam timing is a good idea - but as mentioned - complex - lets see if they do it as good as Lexus or Honda - which do not give any trouble.

There is a company called Aaro Engineering - they build 4 valve conversions for Chev (SB and BB) and Ford (SB and BB) using stock OHV cam location and cores. The 4V is most of the gain to be had. OHC essentially offers real gains over 10,000rpm - so quad cam is not a big deal as their advantages do not offset the added weight for street and most racing applications - not worth a conversion.

I'd love to see Aaro build 4v heads for the Viper - the SB Chev is good for an easy 650hp at 350 cubes and be fully streetable! That is unheard of without boost or NOS. Imagine - the Viper at 930hp without boost and streetable - with plugs fitted from the top like a hemi!!! Easier maintenance, unbelievable power at all rpms with no loss of bottom end but a top end that carries on to 8000, the only down side being mechanical tappets meaning periodic lash adjustments and a bit more width/weight in the heads - a small price compared to the gains.

4V is the most detonation resistant head config available.

They breath over 400cfm in SB form and up to 600cfm in BB form - the best part is they flow hard at low lifts - which is why they are so good on the street and make such good torque. The smaller valves are light and require less spring - so last longer!

re electronic valve tech - Vic - that offers a lot of promise - I'd love to see more on that. F1 spins at 15,000rpm+ - so at half that should be very reliable - plus on a 500 cube engine - everything is bigger and therefore stronger. There's definite potential there added to 4V and direct injection!!! There are already people develing retro direct injection - so the future of hot rodding is looking very exciting.

 

[DEVILDOG]

Yeah, DD, I always wait until its been out for a while, too. I don't wanna be the first-model-year test-dummy either.

Vic,
I'm with ya on that man!

 

[Russ M]

Torquemonster,

The company is called Arao, I have known the owner for over 10 years now. His product is capable in the flow department, but dont expect longevity. His biggest problem is breaking valve train, and he has had the same problem since I have known him.

They will be more than happy to design a Viper cnc 4 valve head, but it is gonna cost you. Figure about 30k in design and development work, followed by many many years of headaches.

 

[Torquemonster]

Torquemonster,

The company is called Arao, I have known the owner for over 10 years now. His product is capable in the flow department, but dont expect longevity. His biggest problem is breaking valve train, and he has had the same problem since I have known him.

They will be more than happy to design a Viper cnc 4 valve head, but it is gonna cost you. Figure about 30k in design and development work, followed by many many years of headaches.

Thanks Russ - good to know! I wondered when I looked at his rockers - like miniture Hemi rockers - fine on a Hemi - but at half size??? I wondered why after all that engineering and flow they didn't use SS rollers like Stage V engineering does on their Hemi's, or a Jesel setup? Then it is just a matter of CNC'g to make a perfect geometry fit each time... ??? Why is he not solving this problem in your opinion?

The other question would also be - are the breakages up around 9000rpm+ - or less?

Maybe he is out of ideas - seems like it may be worth getting a fresh brain in - maybe getting bare castings that flow but leave plenty of material for someone else to perfect the geometry and valvetrain? There are a couple of names that spring to mind....

I like the concept but wonder why everyone who tried this in the past went out of business - MacGee, Batten and several others all tried 4V conversions some with quad OH cams. Seemed to me the Batten and MacGee at least made huge power but got penalised or outlawed whereever they went, and in Top Fuel - the MacGee was just too weak with the smaller moving valvetrain parts. Anything less than Top Fuel - I'd have thought the MacGee could have dominated - esp. ProStock (not eligible of course). The Batten V12 was rumoured to make 2000hp on race gas no boost or NOS.

 

[Russ M]

They keep designing new valve train, but the end result is all the same.

I think it comes down to funding, they are a very small opperation. Their harley 5 valve heads seem to work well, but they cant seem to get the 4valve v8 heads down.

If you are interested I can give them a call and discuss what a Viper version would cost, but I would be very hesitent to use them on my car as a test bed.

 

[Torquemonster]

you have PM

 

[Tom and Vipers]

3 valve is a big improvement.

The intake is what really needs curtain help.

Exhaust is high pressure flow and not a problem like the intake.

3-valve also puts the spark plug in the center of the chamber which is a big improvement.

But the real bit is variable cam timing.

The first big American engine that gets variable valve timing will have the advantage. Hopefully, Benz will feed Dodge.

Of course, the LS1/6 are now toast and the aftermarket will now even be less interested in investing in ANYONE's new high tech engines since they will be obsolete in 5 years. (Like there is no engine aftermarket for Ferrari - so it will be for even Chevy and Dodge.)

Oh, DOHC is very nice for implementing 4-valve configurations. You use simple valve/spring configurations and proven OHC design.

Lingenfelder will have a field day with this if they make it. BTW, I heard he was toast, then getting better. What is the latest on him? I sincerely hope he recovers. He is a treasure.

 

[Torquemonster]

Hey Tom - check out www.feuler.com they may have been involved in the R & D.