Link attached of some cool video files of the new GM 6.2L LT1 (C7 Corvette) engine. I did the testing development work of the AFM (active fuel management) part of the motor. Some good video footage running in the test cell at the GM Pontiac facility. I ran the same test schedule here and not all survived as it is a pretty brutal GED test. Tested and developed for about three years and finished up my work on it about three months ago.
Oops, did I log in to the wrong site?
It worked for me.
Holy cats. That’s some rigorous testing. I’m not a valvetrain engineer, but it reminds me of some of the testing that Porsche does in their dev facility. Impressive!
That CVVT stuff had to be a piece of cake to engineer. 
The money I made went to buy more Cougars, so it is relevant and Cougar related… OK that’s a stretch 
, but I enjoy working on all of them, and knowing the good and bad of a engine before it goes into production.
Nice video BossElim69, I would LOVE to own the new C7 Corvette 
Manta Ray Vert anyone?
How is the amount of fuel controlled with direct injection.
What’s the line pressure on that injection, must be extremely high. I know it’s done regularly these days, often with diesels; but diesels aren’t all that often used in “performance” applications, with the vehicle and engine being tossed around as it was on that one dyno video. I know it works, but whats the PM schedule and projected MTBF?
Sounds like I’m trying to “pick it apart”, but I’m not. Just a little hunger for “How does it work?” knowledge on a Monday morning!
The computer controls the amount of fuel being sprayed in the Direct inject system looking at engine load, timing, o2 sensor, throttle position etc… Gas is supplied to a high pressure fuel pump that runs off a multi lobe on the camshaft. This produces fuel line pressures to the injector at around 2,000 PSI and higher. We test at much higher pressures. Leaner more controlled burn with performance and emission gains.
Actually Diesel engines in some application get more aggressive tilt testing. Cat has a nice tilt bed table to mount a dozer, load etc on to test at very steep angles. A dozer working in a minning operation gets put in a lot of steep angles and has to maintain an oil supply to the oil pump. One time I was there they were tilt bed testing a dozer for Alaska mining at 60 below 0. Marine engines as well get a lot of tilt testing.
whats the PM schedule and projected MTBF? Depends on the test, but usually change oil every 100 hrs. The changing exhaust temps and multi speed changes make the exhaust system flex couplers fail about every 80 hours. That goes for about every dyno test. We use high grade stainless and mandrel bent pipe just to get it to survive that long. In the video it is hard to tell with the lights on, but the exhaust is cherry red running around 1,700 F. Lots of air gets moved in the test cell to keep things like the spark plug boots and wiring harness cooled so they don’t melt.
Cam phasers were developed in the early 90’s so kind of old tech now. Most of the early ones were two step, but now most are going to the continuous phaser. We developed the continuous phaser early before the two steps were on the market. We were too early, expensive and missed the market. Sold the rights, now all the manufactures are using the continuous phaser.
So, do the power levels of this engine make it a challenge in terms of materials, or has that been sorted for a long time?
Materials are “very” challenging, but not due to power levels. Emissions and commodity costs is the driving force that put the materials to the tests. Today’s engines are calibrated to get really hot really fast for a leaner burn that cuts down on emissions (un burnt fuel) going to the converter and stay running at a hot temperature. Really hard on exhaust valves and we have developed several different materials because of this running condition. Better valve material also means more cost and the engine manufactures usually go between a few different materials based on the cost like nickel. The majority of the exhaust valves are Inconel, 21-2n, Crutinite and Eatonite. These articale are a little dated, but contains some good information on materials.
http://www.enginebuildermag.com/Article/2564/valve_alloyswhat_makes_them_so_special.aspx
What is the computer connected to that controls the amount of fuel.
Inconel? expensive stuff.
What does a set of valves cost.
Inconel? So that’s why we’re having a hard time getting wing bolts…
Interesting info, all well above my head. LOL
What is the computer connected to that controls the amount of fuel.
Connected to the piezoelectronic fuel injectors. They have extremely fast response time that allows multiple injection events during each cycle.
Inconel? expensive stuff.
What does a set of valves cost.
Inconel is very expensive, and is the go to material when others fail to work in a given environment. Valve cost is based on: materials used (commodity price) valve manufacturing process and volume. Valve steel material is expensive due to it’s higher quality. No seams, voids and a consistant molecular structure of the steel.
What is the life cycle rating of those.
I know.
I had a contract machining inconel nozzles for the M1 Abrams tank engine.
Very expensive and a b!tch to machine.