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Gm's new 6.6l gas engine

The DI stuff also cools the intake charge much faster, there is a lot of little details I think are left out here with the comparison of the Port injected motors to the DI, the DI motors almost always show a significant torque increase down low. If you compare a 5.3 ls to the LT motor that is very obvious and the other side of this is the VVT is far more capable, add in the super high inj pressure making the atomization less of an issue.. this all adds up. But that doesnt mean GMs gonna come out full tilt, they never do that. So these numbers are likely a conservative calibration that runs stoich all the time. DI creates lots of particulates as it burns the fuel which probably means GM has to do extra to mitigate the dirty burn. Knowing how much was left in my gen iv 5.3 makes me feel like these are easy 100hp gain with a tune and no hardware.. the gen v is a freaking beast when tuned. I for one am stoked about this.
 
yellowK20 said:
The 6.4 Hemi has 410/429 and has been out a few years now ,

These numbers from the 7.3 ford and New 6.6 don’t seem too impressive to me ,

But then again neither does the Hemi
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Man, I'm feeling old here. Still remember when Chevy went from carbs to TBI in the late-80's and everybody was talking about how much more powerful the engines were. There were all types of magazines showing the trucks doing burn-outs and such......and this was with a whopping 200 HP! I think it's amazing you can now get 400+HP out of a "small block" truck V-8 that runs on pump gas, gets reasonable fuel economy, easily starts during any weather, and will run for 250,000+ miles.........

Overall it sounds like the truck market is starting to drift away from the diesel fanfare a little. Sure, the diesel engines definitely have their place in the market but I will say that a LOT of people have spent an extra $10,000 for the diesel engine that they do not really need. With all of the emissions requirements on diesels lowering fuel economy and the increased fuel costs it is definitely closing the fuel savings gap which was a big argument for a diesel. Add in some good horsepower numbers on a gas engine and there you go.
 
6.2Blazer said:
Man, I'm feeling old here. Still remember when Chevy went from carbs to TBI in the late-80's and everybody was talking about how much more powerful the engines were. There were all types of magazines showing the trucks doing burn-outs and such......and this was with a whopping 200 HP! I think it's amazing you can now get 400+HP out of a "small block" truck V-8 that runs on pump gas, gets reasonable fuel economy, easily starts during any weather, and will run for 250,000+ miles.........

Overall it sounds like the truck market is starting to drift away from the diesel fanfare a little. Sure, the diesel engines definitely have their place in the market but I will say that a LOT of people have spent an extra $10,000 for the diesel engine that they do not really need. With all of the emissions requirements on diesels lowering fuel economy and the increased fuel costs it is definitely closing the fuel savings gap which was a big argument for a diesel. Add in some good horsepower numbers on a gas engine and there you go.
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I agree, the gas engine is becoming more appealing when the diesels are getting too costly and inefficient to run as a dd.
 
6.2Blazer said:
Man, I'm feeling old here. Still remember when Chevy went from carbs to TBI in the late-80's and everybody was talking about how much more powerful the engines were. There were all types of magazines showing the trucks doing burn-outs and such......and this was with a whopping 200 HP! I think it's amazing you can now get 400+HP out of a "small block" truck V-8 that runs on pump gas, gets reasonable fuel economy, easily starts during any weather, and will run for 250,000+ miles.........

Overall it sounds like the truck market is starting to drift away from the diesel fanfare a little. Sure, the diesel engines definitely have their place in the market but I will say that a LOT of people have spent an extra $10,000 for the diesel engine that they do not really need. With all of the emissions requirements on diesels lowering fuel economy and the increased fuel costs it is definitely closing the fuel savings gap which was a big argument for a diesel. Add in some good horsepower numbers on a gas engine and there you go.
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The same person that doesn’t need a diesel is the same person that doesn’t need a 3/4 or 1 ton truck ,

As for the cost associated with diesel, some say it doesn’t pencil out . And for the trade it in every 2 year crowd , and the ones who tow a 18ft boat to the lake that’s probably true . But for those that tow heavy , and keep their trucks for a long time the diesels make sense.

Resale value , you get that extra purchase price back at the end and then some .

When a 10 yr old diesel is still selling for 30-35,000 and the comparable gas truck is around 10-12,000

Power , even though the new gassers are impressive on paper , out on the road they are sucking wind compared to the diesels
 
All valid points. I'm not against them as the old L96 6.0 is very long in the tooth.

The 6.6 is a good step forward for a non diesel HD truck. I know we have sold a few 2500 and 3500 gas trucks lately where the customers didn't need max pulling power since they might tow a couple times a year. It will be more as the cost of diesel goes up both for the fuel and the trucks.

Me personally I want them to go further. I've a got a 2004 c4500 roll back wrecker that has 300k on it. I'm on the 4th dirty Max in 15 years. I want to replace it with a gas medium duty and I'm not sure the 6.6 would work for the application. Maybe the 8 or 10 speed trans would help, I'm not sure.

One think to keep in mind on the 8 and 10 speed transmissions. They are busy suckers. Always changing gears up or down. I've seen the 8's do 3 or 4 gear downshifts while climbing. Average John Q. Public don't understand what the hell is going on when it does that like most of us here do. But going from sub 2000 rpm to 4500 or better in a snap to maintain speed is startling. It's definitely something you have to get used too. We saw a lot of that in the switch from 4 speeds to the 6 speed autos.

I'm going to reserve final judgement until I get to drive one.
 
ZooMad75 said:
All valid points. I'm not against them as the old L96 6.0 is very long in the tooth.

The 6.6 is a good step forward for a non diesel HD truck. I know we have sold a few 2500 and 3500 gas trucks lately where the customers didn't need max pulling power since they might tow a couple times a year. It will be more as the cost of diesel goes up both for the fuel and the trucks.

Me personally I want them to go further. I've a got a 2004 c4500 roll back wrecker that has 300k on it. I'm on the 4th dirty Max in 15 years. I want to replace it with a gas medium duty and I'm not sure the 6.6 would work for the application. Maybe the 8 or 10 speed trans would help, I'm not sure.

One think to keep in mind on the 8 and 10 speed transmissions. They are busy suckers. Always changing gears up or down. I've seen the 8's do 3 or 4 gear downshifts while climbing. Average John Q. Public don't understand what the hell is going on when it does that like most of us here do. But going from sub 2000 rpm to 4500 or better in a snap to maintain speed is startling. It's definitely something you have to get used too. We saw a lot of that in the switch from 4 speeds to the 6 speed autos.

I'm going to reserve final judgement until I get to drive one.
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Sounds like the rollback needs an 8.1 :thinking:
 
SpeedlabDan said:
Sounds like the rollback needs an 8.1 :thinking:
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8.8 DI sounds better. We'd never go through the effort of a diesel to gas swap on that truck. Too old and not cost effective. Cheaper in the long run at this point to buy a new truck. Latest quote I got for a 2020 c4500 diesel was like $88,000 with the wrecker body fitted. I've got the owner at least on the same page to look at a gasser and not buy anything yet.
 
ZooMad75 said:
8.8 DI sounds better. We'd never go through the effort of a diesel to gas swap on that truck. Too old and not cost effective. Cheaper in the long run at this point to buy a new truck. Latest quote I got for a 2020 c4500 diesel was like $88,000 with the wrecker body fitted. I've got the owner at least on the same page to look at a gasser and not buy anything yet.
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8.8di gas?
 
ZooMad75 said:
Psi is working on an 8.8L big block with direct injection and possibly variable cam timing too. Gonna be a hell of a school bus engine...
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Like previously mentioned, there's gotta be some GM engine guys kicking themselves over that one.
 
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i somewhat understand the point about the transmissionses having 8,10,12 gears and have taken that into consideration. i still want to see the torque curves of both the 6.6 and 6.2.

Like a few others, i'm perplexed about the need for this new 6.6 engine, when the 6.2 produces similar peak numbers----at first glance. Again, let's see the torque curves.
 
yellowK20 said:
The same person that doesn’t need a diesel is the same person that doesn’t need a 3/4 or 1 ton truck ,

As for the cost associated with diesel, some say it doesn’t pencil out . And for the trade it in every 2 year crowd , and the ones who tow a 18ft boat to the lake that’s probably true . But for those that tow heavy , and keep their trucks for a long time the diesels make sense.

Resale value , you get that extra purchase price back at the end and then some .

When a 10 yr old diesel is still selling for 30-35,000 and the comparable gas truck is around 10-12,000

Power , even though the new gassers are impressive on paper , out on the road they are sucking wind compared to the diesels
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I disagree with this. Many people absolutely need the strength of a 3/4 or 1 ton, but don't need the added costs of a diesel. My example is Fords, but it applies to most. My boss bought a small fleet of '12 F350's and ordered only a few options, he only picked the ones needed to get the job done, and a few for operator convenience. Those trucks have pulled a lot of heavy loads (20-25k) with the gasser 6.2's and while they are not a good truck engine, they do get the job done. Other than some coils, wires and a couple alternators, they have needed very little maintainence in their 200k+ service life and the service they have needed was cheap. They are still in service now too. Another plus, being a gasser, we can leave them in remote locations for weeks or months at a time, and when we get back to them, they start right up no matter how cold it is.

For what we have used them for, there's no way we could have done the same kind of work with a 1/2 ton truck. And while the resale value may have been higher with a diesel, it doesn't matter because the trucks will continue to get used until they are literally worthless besides scrap.

Also, I don't think it's wise to purchase a vehicle based on expected resale value. People currently pay stupid amounts of money for diesel trucks with limited amounts of life left, just so they can say they have a strong diesel. The diesel craze may not last that long. It could, but it may not.
 
ZooMad75 said:
Psi is working on an 8.8L big block with direct injection and possibly variable cam timing too. Gonna be a hell of a school bus engine...
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I assume PSI sells the current 8.8 in crate form for replacement purposes, any idea on cost? I looked around on the internet a bit with no luck.
 
@ZooMad75 that seems crazy that your dealership has a truck on its 4th engine. I know a guy who has 260K on a D-max which he has put the trans in limp mode more than twice while towing in "extreme " on his tuner. No, he doesn't tow with it daily, but it has a service bed on it full time. And one of his other trucks drove 50 miles with no fan to get into town. I accidentally got a blister trying to change the idler pullies. The guy said the temp gauge was pegged when he shut it off, but I thought that an hour was long enough to tackle it.
:doah:
It still is going.

Sorry for the derailment.
 
USSkoval said:
I disagree with this. Many people absolutely need the strength of a 3/4 or 1 ton, but don't need the added costs of a diesel. My example is Fords, but it applies to most. My boss bought a small fleet of '12 F350's and ordered only a few options, he only picked the ones needed to get the job done, and a few for operator convenience. Those trucks have pulled a lot of heavy loads (20-25k) with the gasser 6.2's and while they are not a good truck engine, they do get the job done. Other than some coils, wires and a couple alternators, they have needed very little maintainence in their 200k+ service life and the service they have needed was cheap. They are still in service now too. Another plus, being a gasser, we can leave them in remote locations for weeks or months at a time, and when we get back to them, they start right up no matter how cold it is.

For what we have used them for, there's no way we could have done the same kind of work with a 1/2 ton truck. And while the resale value may have been higher with a diesel, it doesn't matter because the trucks will continue to get used until they are literally worthless besides scrap.

Also, I don't think it's wise to purchase a vehicle based on expected resale value. People currently pay stupid amounts of money for diesel trucks with limited amounts of life left, just so they can say they have a strong diesel. The diesel craze may not last that long. It could, but it may not.
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Fleets I can kind understand going with gas trucks , I was talking about the average joe consumer.

And like out not , a gasser with 200,000 vs a Diesel with 200,000 Diesel wins hands down .

Residual value IS important , not as important to fleets because they can write it off but to the guy trading his truck in on a new one it makes a huge difference. 10,000 in trade in equity makes a huge difference on that new payment.

(I never trade mine in just saying)
 
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