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Is the 6.4 liter 392 a direct injection Engine?
sorry I do not know much about the 392. I have read that Direct injection is new for gas engines?
GM is changing silverados from the 6.0 liter to a 6.6 with direct injection? Made me wonder if the
392 is a direct injection engine?

I love it Now w/ 1735 miles I cant stop smiling
 

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I've heard direct injection is not good since it puts fuel directly in the cylinder and bypasses the intake valve.

This creates carbon buildup on the valves and the fuel additives that prevent carbon buildup isn't being introduced through the valves.

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If that was true and direct injection is bad for valves, then how is it diesel engines don't suffer from this?
 

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Nope, port injected. Direct does tend to carbon up valves since they don’t get washed by fuel. Some are going both port and direct these days.
 

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If that was true and direct injection is bad for valves, then how is it diesel engines don't suffer from this?
Some diesel engines do suffer from this. There was a lot of talk about this when I bought a 2002 VW Golf TDi. Owners were going crazy coming up with all sorts of things to deal with this.

The problem arose not from the direct injection per se but from the exhaust gas recirculation which was intended to keep combustion temperature below the threshold of NOx formation.

It did this but a big negative was the exhaust gas recirculation introduced soot into the intake and this combined with crankcase vapor to in some cases coke up the intake to the point the engine would barely run over idle speed.

Just prior to selling my Golf TDi about 6 years after I bought it and with just under 150K miles I checked the intake and found while the intake walls were coated with an oily black layer of soot the thickness was just oil film thick. There was no build up.

What I did and I guess it "worked" was to 1) Change the oil often. Every 5K miles often. The factory called for 10K mile oil changes but oil run this long is prone to excessive vaporizing and this just means more vapor to possibly foul the intake; 2) Avoid real low RPM operation. Many owners treated their TDi like a big rig engine and short shifted the engine -- automatic equipped cars already did this -- (mine was a manual) -- and this low RPM operation was apparently particularly bad from an intake fouling point of view.

I didn't run the engine at redline all the time but I kept the RPMs up some. And the result was intake fouling coking up never happened.
 

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Nope, port injected. Direct does tend to carbon up valves since they don’t get washed by fuel. Some are going both port and direct these days.
While the backs of intake valves do not get "washed" by port injector spray combustion gases back flow into the intake -- which is one contributor to the buildup of deposits on the backs of the intake valves -- combined with the right gasoline -- Chevron with Techron -- when combustion gases back flow into the intake the Techron in vapor form helps to keep the intake valves clean.

My MINI JCW is a direct port injected engine and I run a tank of Chevron gasoline oh every 5th or 6th tank for this reason.

To minimize oil vapor and it contributing to intake valve deposit formation I change the JCW engine oil every 5K miles -- vs. 10K miles the factory calls for -- and I also avoid real low RPM operation. While the engine produces good torque at lower engine speeds I avoid real low RPM operation. By operating the engine at higher engine speeds this minimized combustion gas back flow and reduces the amount of deposits Techron has to remove.
 

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I think a direct injection engine would benefit the most from a catch can too.
Nah. I'm not a fan of catch cans. Gasoline has a bit over 1/2 ounce of oil in it from the refinery. So over 5K miles at 30mpg average that's 166.7 gallons of gasoline and over 166.7 ounces of oil. That's approx. 1.3 gallons of oil.

If people were pulling around that much oil out of a catch can over 5K miles I might think a catch can necessary. (Or a better engine.)

The engine doesn't appear to have any oil in the intake based on the fact I have never ever seen it smoke on cold start.

OTOH, with my other cars smoking upon cold start was while infrequent something that I observed happening at any time but most often towards when it was getting time to change the oil.

And the JCW does not use any oil. I check the oil level right after an oil change and it is at the max level. Then after every refueling and over 20K miles the engine has not used any oil.
 

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The Honda 4 cyl DI engines have had a problem with oil dilution. They had a TSB and the oil needed to be changed & some software needed to be updated, and in some cases a control part needed to be replaced.

Apparently oil dilution is a fairly common issue with DI.

If you Google the problem you’ll get a bunch of results.

I’m glad the 6.4L is not DI.
 

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Is the 6.4 liter 392 a direct injection Engine?
sorry I do not know much about the 392. I have read that Direct injection is new for gas engines?
GM is changing silverados from the 6.0 liter to a 6.6 with direct injection? Made me wonder if the
392 is a direct injection engine?

I love it Now w/ 1735 miles I cant stop smiling
No, it is not. Diesel engines are due to the nature of the compression ignition combustion cycle. Direct Injection for a spark ignition engine is a flawed idea. Spark ignition engines depend on the turbulence of the air going through the valve to help air-fuel mixing. It's also why carbureted engines tend to put out more power at W.O.T. if properly set up because the mixture is more homogeneous going into the cylinder.
 

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FWIW, While living in Japan, I owned a few Japan only vehicles that were direct gas injection. ZERO issues, great performance, great mileage.
 
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