New Gen 5 GM V8

[puttputt]

For those of us looking for an engine, GM is introducing the new gen 5,
seems it will still be a pushrod OHV, but with direct fuel injection, as well as continously variable valve timing (how they do CVVT with pushrods is beyond me), fuel consumption for the 6.2 L will drop to 9l/100km or 26mpg in American speak, that is amazing, the LT1 version will produce 335kw and 610nm.

I was keen on the 6.2 gen 4 gen but was concerned about the heavy fuel usage, as much as 14,5 to 15 l/100km. This is the way to go. Lets hope they are not too expensive.

[Modena]

all the good info here, it is set to be a pearler, very interesting with the 150BAR mechanical fuel-pump setup;

Gen V "LT1" Small-Block - Popular Hot Rodding Magazine

[Aussie Mike]

Originally Posted by puttputt

how they do CVVT with pushrods is beyond me

Easier than an OHC motor. Only one cam to advance or retard. There will be a mechanism incorporated into the cam drive to advance or retard the cam timing as required. That's all variable valve timing is.

It's about time we saw direct injection on production petrol engines. Diesels have been using it for years. The extremely fine fuel atomization means you have a much better homogenized mixture in the chamber and a more efficient burn. You are also not reliant on the vagaries of cylinder vacuum and port flow to ensure you get the right ammont of fuel and air in the cylinder at the right time.

Funny thing is an Aussie pioneered a lot of this technology. Look up a fellow named Ralph Sarich. He came up with a lot of these ideas back in the 70's

Cheers

[Jerry Clayton]

Yep Mike--a lot of tech in the 70s was down played and swept under the table by the governments and oil companies---if we couldn't develope a fuel shortage, we wouldn't need OPEC and the world oil economy!!!!!!!!!!!!

[puttputt]

Isn't it wierd, yesterday I was deciding on whether I go 6.0L doing 12L/100km, or more powerful 6.2L but only 14.L/100km, so I thought maybe if I google 'new GM V8" I will get lucky, and bingo.... now how do I get my hands on one ?

[Jerry Clayton]

If they do it like the LS7 and ZL1, you can probably go to Wixom, Mich engine plant and put it together---You just can't fly in on a corporate jet--------

[Gaz64]

Direct injection is ok for a while, but some engines carbon up really bad from no fuel in the inlet port to keep the back of the inlet valves clean.

Seen many issues with DI.

[Zedn]

It's coming out in the new hsv but I suspect it will be a while before the cheap crate motors start to circulate. Chances are the money you save on fuel will be spent on the motor. You then need the tuning houses to get them figured out.

Is fuel consumption really an issue? I haven't really even considered it when building a replica of a race car.

[joyridin']

I can't speak for Aussie land, but here in the USA, they really haven't started manufacturing them yet. I visit the GM casting/rough machining facility and the blocks are piled up waiting to be machined. They did about 200 of them a while back for prototyping and testing, but none for production purposes yet.

[Gaz64]

I'll take my Holden hat off that I've worn all my mechanic working life, now 34 years.

AFM (formally known as DOD - displacement on demand) is a great theory and does work well UNTIL an AFM lifter rotates in the poorly designed lifter guide.

And it will happen, seen a few failures.

Then it is heads off and camshaft change.

Each to their own about petrol direct injection, but the new Gen 5 is the next step forward (or back in some eyes) for emissions.
The hard fact is proof in pudding. The inlet valves are more prone to carbon buildup with no fuel sprayed at them.
To have high flowing cylinder heads ex factory that carbon up and lower potential airflow into the cylinder is backwards step.
Current port EFI engines can stay almost as new on high quality PULP.

[Aussie Mike]

Originally Posted by Gaz64

The inlet valves are more prone to carbon buildup no fuel sprayed at them.

Is this what you have seen from the SIDI V6 motor?

How does the carbon build up on the valve? Is it blown back out of the chamber as the inlet valve opens?

I wonder if a water injection system would help. It's a side effect I've seen turbo motors with water injection that they have clean combustion chambers when pulled down.

Carbon buildup is a problem on direct injection diesels more because of the EGR systems used which recirculate exhaust gasses into the intake for a 2nd burn. I pulled the whole setup off my land rover diesel when I did a VNT turbo conversion. It was really gunked up in there.

Cheers

[Gaz64]

Originally Posted by Aussie Mike

Is this what you have seen from the SIDI V6 motor?

How does the carbon build up on the valve? Is it blown back out of the chamber as the inlet valve opens?

I wonder if a water injection system would help. It's a side effect I've seen turbo motors with water injection that they have clean combustion chambers when pulled down.

Carbon buildup is a problem on direct injection diesels more because of the EGR systems used which recirculate exhaust gasses into the intake for a 2nd burn. I pulled the whole setup off my land rover diesel when I did a VNT turbo conversion. It was really gunked up in there.

Cheers

Mike,


Of the SIDI motors I've had the intake off, the reason is to ascertain the cause of pinging and oil consumption.

The majority of these have the buildup, I've yet to see a "good one", certainly haven't seen anything as good as my own cars.

The carbon on the back of the inlet valves is blowby engine oil from the rocker cover/inlet manifold combo.
Poor ventilation system design. Could also be valve guide lubrication past the guide seal.

One of my cars runs AEM water injection and 98 PULP. The inlet manifold and inlet ports are spotless.

[sideshow]

direct common rail injection on diesels is ok till u get water in the fuel
once water gets into the rail and the rail rusts then in a hilux to fix it can be up towards 8000 bucks to repair
thats a 1/4 of the price of the car if its 2 or 3 years old
they run around 26000 psi fuel pressure in rail and when u get tiny water particles in the fuel and then in the rail the hi pressure pushes the water into the porous metal tube inside the rail

i wonder if this issue will be similar with the direct petrol injection too

[Gaz64]

Originally Posted by sideshow

direct common rail injection on diesels is ok till u get water in the fuel
once water gets into the rail and the rail rusts then in a hilux to fix it can be up towards 8000 bucks to repair
thats a 1/4 of the price of the car if its 2 or 3 years old
they run around 26000 psi fuel pressure in rail and when u get tiny water particles in the fuel and then in the rail the hi pressure pushes the water into the porous metal tube inside the rail

i wonder if this issue will be similar with the direct petrol injection too

Another reason why I don't like direct injection.

[sideshow]

i did a day diesel course down in canberra a year ago
was very interesting stuff about new diesels
nissan also has a new petrol v8 in their new patrol
except the car is worth 105 thou

[Gav]

Originally Posted by Gaz64

Another reason why I don't like direct injection.

I'll go out on a limb here and say I reckon you want to start to get used to it!

[Aussie Mike]

I don't know what the fuss is about. I've had 3 direct injection diesels now and not had any injection trouble with any of them.

The Land Rover I had used an extra cam to drive a piston pump on each injector to achieve the ultra high pressures. The fuel pump was actually not much higher pressure than a regular petrol pump. I think our VW uses the same system. A bit more complicated than common rail.

They all have a water sensor in the fuel filter and an idiot light on the dash. So as long you don't do anything silly like running it with the light on and doing nothing about it you shouldn't have any trouble.

Cheers

[sideshow]

Yes but the two percent of us that know what the lights mean we will stop

But the rest will keep driving till she stops hehehe
But the ecus are getting smarter
Like any car. If u don't maintain it then it will fail
And cost a ****loads to fix afterwards

[sambo]

Volkswagen have been using FSI (fuel stratified injection) since 2000. It was adapted from their Le Mans car. I've had the TFSI engine (turbo FSI) in two GTIs since 2006 and they keep being awarded engine of the year, so direct injection isn't necessarily a bad thing.

They do get carbon build up on the intake valves and intake runners, which hurts performance over time and in really bad cases can damage intake valves and other components. A catch can lessens this to an extent, but my mechanic recommends spraying a decarbonising solution down the intake from time to time. Eventually with enough kms all of these engines will benefit from a tear down and a proper clean. This is recommended at the same time as they do timing belts, cam followers, etc. I doubt many Cobras will be doing that many miles though - in the order of 100,000+.

[tomcat racing]

Run Moreys fuel additive in your petrol or diesel engine and the carbon build up, black smoke, and fouled injectors is a thing of the past, 1 litre does 650 ltrs of fuel, THE best product going around, ive been using it for years.