[Tom Vaught]

Push-rods no more. GM’s recent patent for an LT5, along with leaked documents point to at least one Corvette model having dual overhead camshafts.

http://ls1tech.com/articles/the-2018...mpaign=content

You can play a lot of games with DOHC, 4 Valves, and BOOST!

Pontiac Engineers will never get credit for any of that earlier work, but we know it happened.

Tom V.

[tom s]

Tom,I saw a 2018 engine code list that showed a turbo dsl but dont know application.Bet it would be the Canyon mid truck.Also a hybrid 4 cyc engine.Tom

[Half-Inch Stud]

Coool, GM can catch up to the FORD DOHC 4.6L.

[Tom Vaught]

They will catch up fast, HIS, even though we did the first DOHC 4.6 stuff (in production around 1995 time frame).

The driver on this technology is the cylinder deactivation technology.

Tom V.

[Half-Inch Stud]

Originally Posted by Tom Vaught

.........The driver on this technology is the cylinder deactivation technology. Tom V.

You know, if the intake valves to a power-pair (example 1&6) could be kept closed, then the fuel injectors for that power pair could be turned off, for 8-6, shut another pair off for 6-4.
And that keeps the O2 sensors happy. The 8-6-4 Cylinder engine done the right way.

[Tom Vaught]

Agree HIS, exactly how it needs to be done.

But then you also play games with the exhaust valves to reduce Pumping Work.

Tom V.

[70 bird]

Yep, heard some talk from a gentleman that works at power-train performance center, GM's new direction is DOHC for the vette. The most interesting comment I heard was GM hated using boost to keep up with ford and chrysler and the main focus of the new powerplant was a spin to moon design! RPM's He couldn't tell me what kind of RPM's but just laughed and said its way up there!

[Dragncar]

My 07 Tundra has a DOHC hemi, and it freakng runs. Its so de tunned. When I first got it it would rev right away to 6300 or so, ET the 5700 pound truck at 14.56. Now it hits the rev limiter at 5400. sucks. Is way overbuilt , wide engine with a big cast aluminum oil pan. Holds almost 8 qts.
Bet if you shoved it into a 3400 car it would run 11s. Kind of wonder what the bottom end looks like.
And yes, PMD will never get credit for being OHC innovators. 3 valve OHC 428s, and 2 valve inline OHC 6s. Then the SOHC 427 Hemi modular engine. It all started with the WWII era gasoline aircraft engines. Smokey U, who was a B-26 pilot said they took the tech from planes to cars.
If it were not for WWII there would have still been flat heads from Detroit in the 60s.That war was the biggest single event in human history for tech innovation. Think of where we were before and after it.

[Tom Vaught]

I shifted the MULE 4.6L boosted engine many times in the 8000+ range so I can believe that deal.

Tom V.

[Jack Gifford]

Originally Posted by Tom Vaught

... You can play a lot of games with DOHC, 4 Valves, and BOOST!...

If it were me doing the "playing" I'd also want full-VVT- to heck with cylinder-deactivation nonsense.

[Tom Vaught]

Two separate systems as you know Jack but the VVT Technology is years ahead of the cylinder-deactivation. It is in production on quite a few engines today sourced from several vendors. Just need the camshaft VVT computer strategy in a decent computer package.

Variable Valve Timing (VVT) Components

Metaldyne Corporation in Plymouth, Michigan
100% Match: variable valve timing (VVT) components

Metaldyne SinterForged Products, LLC in St. Marys, Pennsylvania
94.9% Match: VVT components

Miba Sinter USA, LLC in McConnelsville, Ohio
75.8% Match: variable valve train (VVT) components

Metal Seal Precision, Ltd. in Mentor, Ohio
73.3% Match: variable valve timing

Mikuni American Corporation in Northridge, California
73.3% Match: variable valve timing (VVT) systems

Camcraft, Inc. in Hanover Park, Illinois
73.3% Match: variable valve timing control valves

DENSO Mexico S.A. de C.V. in Apodaca, Nuevo Leon
73.3% Match: variable valve timing sensors

EKK Eagle Sales America, Inc. in Farmington Hills, Michigan
73.3% Match: VVT solenoid valves

Metaldyne Performance Group, Inc. in Southfield, Michigan
70.9% Match: variable cam timing components

Tom V.

[taff2]

The new Freevalve technology will be the way of the future I think, pneumatic/hydraulic/electrical solenoids used to activate the valves,all controlled by the ECU. Valves could be opened and closed precisely when you want them to. Software companies will be able to offer a switchable economy map and a high performance map. Koenigseggs, the supercar builders have the technology now.

[Tom Vaught]

Thanks for the additional resource Taff2, very big technology shift for some but the favorable result of variable timing on the camshaft has been known since the Veri-Cam timing chain Sprocket from the 60s. P-Jack would remember that deal.

Tom V.

[694.1]

" It all started with the WWII era gasoline aircraft engines. "
J.Z. Delorean's previous employer (Packard) built 50K+ Rolls Royce Merlins for the war effort and I expect he was influenced by these engines. It's a great read, the history of the sea plane racing technology that spawned the development of the Supermarine Spitfire and the RR Merlin engine. More great reading is the development of the German technology from their pre war GP involvement. They were not supposed to be developing military tech after the Great War but their racing program served the purpose quite nicely.

[Goatracer1]

To Dragncar, I worked for AMC in the 60's and there were flatheads. They were still using a 196 cid flat head 6.

[Jack Gifford]

Originally Posted by Tom Vaught

... ft has been known since the Veri-Cam timing chain Sprocket from the 60s...

I remember it well. But the one I copied a few years ago was Ollie Morris's Cam-a-Go, which offered more flexibility compared with Vari-Cam's centrifugal deal. As sold by Offenhauser (Ollie was Fred's partner) Cam-a-Go moved the idler gear with engine oil pressure (or optional mechanical cable control). But I built an electrical servo to move the idler, based on a tach signal. It's in storage now, waiting for me to re-do it with helical gears, to quiet it down.

[Tom Vaught]

There are simple electric actuators that control the oil pressure to the phasers like the Ollie deal out there today. Ollie was way ahead of his time.
Your deal is impressive, Jack.

Tom V.

[nachomax]

How about camless like the Koenigsegg?

https://youtu.be/OZWeNPi2XkE

https://youtu.be/S3cFfM3r510

[Jack Gifford]

Almost "square" areas under the valve-lift curves. Yeah!
And every engine is its own Spintron- simply display/plot the output of the valve-position sensors. [I hope my sarcasm is obvious; no more need for a Spintron]

[seancarole]

sb4
http://www.mercuryracing.com/automotive/
if only ved , cvwhat , kre who , butler what , ETC. and so on would just do it. wow it would be wicked



Build it and they will come