The Inevitable Comparison: GM 6.6 vs. Ford 7.3

2016HD · February 7, 2020

3 hours ago, KARNUT said:

This is unreal. If you can maintain speed at 3K RPM there’s no reason to downshift. If you need to run 4-5 K for a prolonged period of time you need to regear or go diesel. No gas engine is going to run hour after hour at 4-5K and live very long. Before diesel in P/Us I hauled with gas one tons. Engines usually barely made 100K just running 3K with out rebuilding. Diesel became popular in 3/4-1tons simply because they made max TQ at lower RPMs, maximizing life. Six - ten speed transmissions allow gas engines to stay in TQ range at lower engine speeds. Steep grades occasionally running higher engine speeds is to be expected. Otherwise no need.

So How many small blocks have you owned?? Reason for them not living past 100000km was do to a lack of proper maintenance And OR the lesser quality of materials used for production along with cylinder wash down from improperly tuned carbs. I've never had an issue getting a 350-400hp small block to live past 100000 other than the old style oil pan and main gasket issues. You state running a gas engine at its torque range!! So what exactly do you think the torque range of a modern Ls Or l8t is?? These engines are designed and built to run in the 4000 Rpm range all day long!! And that is where they work the best. If i own a gas 3/4 its because I dont need Or want a diesel!! And yes my gas engine pulling 7000lbs with a fully loaded box will Pull second gear doing 50mph at 4500-4800 consistently during our summer vacations in the mountains. At an 8% grade it wouldnt hold speed even at 3000 rpm because you are under the torque curve and way below the Horse power range. Diesels became popular because they make more than 500lbs of torque and are slightly more efficient along with Diesel was a lot cheaper at the time. Oh wait and you can ROl Coal!- waste, But we are all allowed our opinions and experiance.

KARNUT · February 7, 2020

5 hours ago, 2016HD said:

So How many small blocks have you owned?? Reason for them not living past 100000km was do to a lack of proper maintenance And OR the lesser quality of materials used for production along with cylinder wash down from improperly tuned carbs. I've never had an issue getting a 350-400hp small block to live past 100000 other than the old style oil pan and main gasket issues. You state running a gas engine at its torque range!! So what exactly do you think the torque range of a modern Ls Or l8t is?? These engines are designed and built to run in the 4000 Rpm range all day long!! And that is where they work the best. If i own a gas 3/4 its because I dont need Or want a diesel!! And yes my gas engine pulling 7000lbs with a fully loaded box will Pull second gear doing 50mph at 4500-4800 consistently during our summer vacations in the mountains. At an 8% grade it wouldnt hold speed even at 3000 rpm because you are under the torque curve and way below the Horse power range. Diesels became popular because they make more than 500lbs of torque and are slightly more efficient along with Diesel was a lot cheaper at the time. Oh wait and you can ROl Coal!- waste, But we are all allowed our opinions and experiance.

We sold hay from our farm pulled our equipment to job sites and went to horse shows on weekends. Did it with gas one tons in the sixties until diesels were available. We ran Chevys and Fords, small and big blocks usually modified. We would add gear vendors to our transmissions to do the opposite of what you say your doing for engine longevity. For fun we built cars to race on the weekends when we had time. When diesels became available the had around 160 HP 400 ft lbs of TQ. The had less HP around the same TQ reached at lower RPMs. Today there’s more gears and HP- TQ to do the work. Extreme RPMs are reserved for extreme conditions, not the norm. How many trucks have I’ve experienced? Dozens on the family farm and our business.

KARNUT · February 7, 2020

1 hour ago, KARNUT said:

We sold hay from our farm pulled our equipment to job sites and went to horse shows on weekends. Did it with gas one tons in the sixties until diesels were available. We ran Chevys and Fords, small and big blocks usually modified. We would add gear vendors to our transmissions to do the opposite of what you say your doing for engine longevity. For fun we built cars to race on the weekends when we had time. When diesels became available the had around 160 HP 400 ft lbs of TQ. The had less HP around the same TQ reached at lower RPMs. Today there’s more gears and HP- TQ to do the work. Extreme RPMs are reserved for extreme conditions, not the norm. How many trucks have I’ve experienced? Dozens on the family farm and our business.

I will add that 6.0 reaches its max TQ approaching 35-4K RPMs It’s not much lower at 3K RPMs. The only reason to go pass that is to shift to the next gear if pulling a load or grade. Holding 4K RPMs is a waste.

Edited February 7, 2020 by KARNUT

kenny_r · February 7, 2020

I found in my 17 6.0, it seems to do its best work around the 3-3500 rpm range which is like 4th I believe. I do wish it had a lil more down low because in a good wind with the trailer, it seems to lock into 4th and it won’t come out. It’s annoying at times. Oh well.lol

Carolina · February 7, 2020

11 hours ago, KARNUT said:

This is unreal. If you can maintain speed at 3K RPM there’s no reason to downshift. If you need to run 4-5 K for a prolonged period of time you need to regear or go diesel. No gas engine is going to run hour after hour at 4-5K and live very long. Before diesel in P/Us I hauled with gas one tons. Engines usually barely made 100K just running 3K with out rebuilding. Diesel became popular in 3/4-1tons simply because they made max TQ at lower RPMs, maximizing life. Six - ten speed transmissions allow gas engines to stay in TQ range at lower engine speeds. Steep grades occasionally running higher engine speeds is to be expected. Otherwise no need.

You do realize that a diesel running 2500-3000 rpms is the the same as a gas running 4000-5000? Like I said 300,000 miles and I’ve changed a battery . My duramax has had the transmission control module changed , thermostats and glow plug after glow plug

Edited February 7, 2020 by Carolina

KARNUT · February 7, 2020

5 minutes ago, Carolina said:

You do realize that a diesel running 2500-3000 rpms is the the same as a gas running 4000-5000? Like I said 300,000 miles and I’ve changed a battery . My duramax has had the transmission control module changed , thermostats and glow plug after glow plug

What?! I have no words.

Carolina · February 7, 2020

1 hour ago, KARNUT said:

I will add that 6.0 reaches its max TQ approaching 35-4K RPMs It’s not much lower at 3K RPMs. The only reason to go pass that is to shift to the next gear if pulling a load or grade. Holding 4K RPMs is a waste.

KARNUT · February 7, 2020

2 minutes ago, Carolina said:

Nice of you to prove my point. Look at the TQ.

Carolina · February 7, 2020

15 minutes ago, KARNUT said:

Nice of you to prove my point. Look at the TQ.

You stated holding 4K is a waste . It doesn’t reach max until 4200 . The torque is still at the level of 3500rpm when you reach max horsepower so in fact running 5k will give you more torque than 3500 rpm and a lot more horsepower which will pull better

2016HD · February 8, 2020

13 hours ago, KARNUT said:

We sold hay from our farm pulled our equipment to job sites and went to horse shows on weekends. Did it with gas one tons in the sixties until diesels were available. We ran Chevys and Fords, small and big blocks usually modified. We would add gear vendors to our transmissions to do the opposite of what you say your doing for engine longevity. For fun we built cars to race on the weekends when we had time. When diesels became available the had around 160 HP 400 ft lbs of TQ. The had less HP around the same TQ reached at lower RPMs. Today there’s more gears and HP- TQ to do the work. Extreme RPMs are reserved for extreme conditions, not the norm. How many trucks have I’ve experienced? Dozens on the family farm and our business.

Well you are a bit older than I. However raised on a farm myself. Along with 15 mins from local drag strip. Tons of engine builds along with transmission builds etc. And yes very familiar with Gear Vendors. I think you miss understand what im saying. I dont run 4000rpm on flat ground!! While towing. No need with 400flbs. However when Towing a trailer and fairly loaded box. Up 5-8% Grades, you need to keep the engine at or slightly above its torque peak!! This means second or third gear depending on grade and load. You absolutely should not be pulling steep grade while loaded at 3000rpm. Unless you want to risk losing a rod bearing or main do to fuel knock and Lugging. This can be safely sustained for 20mins or more as this is what the gas engines of modern design are built to withstand. This is why the 6.0l stayed in the HD for so long. Durability testing. The 6.2 420hp engine for example will not last under these same conditions as its built as more of a hot rod engine even though its in the 1/2ton trucks. Not sure why you think i would run above 4000rpm under all conditions? This is about towing and where I live. There is a ton of Mountains and no way around it. SO 4500rpm second gear around 7500lbs trailer and 2500lbs in the bed. Minimum 10 min straight on most trips. Have owned and built 6 small block 355 in half and 3/4 tons. First 2 are still around at over 200000km on the build tons of towing and work hours. Latest truck before my 16 was a 2001 2500hd Lq4 Basic rebuild when purchased along with trans rebuild. Cam/headers/ tune etc. Great towing truck! Sold at 250000km no leaks or repairs after my build. Towed great! Even picked up 3rd gear with the 4l80e doing the same towing up 8% grades, While at 110-120kmh in 3rd at 4500RPM. Each there own we all have our experiences! I hate diesels! and the FAD that they created. Great for working and if i towed 15000lbs daily I might own one. Or id Supercharge an LS. Peace.

2016HD · February 8, 2020

14 hours ago, Carolina said:

Edited February 8, 2020 by 2016HD
wrong quote

Ray Pickle · February 8, 2020

So someone intimated that you a3hould always tow at 4 grand? Talking about the ike weren't we? These conversation always go to the ridiculous. I would bet towing at close to torque peak these two trucks would be within 200 yards of one another at the top of the ike

Carolina · February 8, 2020

11 hours ago, 2016HD said:

Torque moves shit and Horsepower keeps it moving.

The truck has more capability to accelerate at 5000 rpms because it has more torque than at 3500 and will be harder to slow down because it’s near it’s peak horsepower and will have the least chance of slowing down at its max horsepower. That’s why you punch the bitch to keep speed

Edited February 8, 2020 by Carolina

Carolina · February 8, 2020

13 hours ago, KARNUT said:

What?! I have no words.

Your concern of the gas engine lasting . The wear is similar on a diesel at those rpms.Also downshifting gives it the opportunity to have more horsepower to keep it from slowing down. Nobody is trying accelerate up hills there trying to maintain speed . If you don’t think diesels have to rev on hills you must have never towed with one with a big load up a hard grade . I’ve watched my duramax loose speed many times and had to floor it only to watch it fall

07HD · February 8, 2020

On ‎2‎/‎7‎/‎2019 at 1:18 AM, C/K Man said:

We don't know the whole story yet, but some of my observations so far: Looks like GM simply when with an enlarged Gen. V version of the current L96. Other than increased displacement, the only new features appear to be a forged crankshaft and direct injection. The horsepower and torque figures are impressive and should be more than adequate even in a medium duty truck. The engine has nothing in it that has not been in other LS engines for years, and should be completely reliable and as durable, if not more so, than the L96. The Ford 7.3 is a completely new engine platform unrelated to any existing Ford engine. Ford had to take this approach supposedly because the 6.2L was unsuited for medium duty truck use. The 7.3 is not technically advanced and is strikingly similar in some regards to the LS. It's bore spacing is a little larger than the LS. Since Ford was not constrained using an existing engine's tooling, they probably figured what displacement they wanted and sized the block accordingly. Ford has not released H.P. and torque figures yet. I expect the 7.3 to have a little more H.P. and torque than the 6.6, but I think the 6.6's direct injection will largely make up for its smaller displacement. I also think the 6.6 will be more fuel efficient. And, I think GM spent a lot less money to develop their new engine.

But the 7.3 is still old school technology ?