New GMC 4 banger, 310 hp, 420 ft-lb torque

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IBTripping

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I continue to be amazed at the power truck makers get out of smaller engines. The base 2022 GMC Sierra has a 2.7L 4-cylinder turbo with 310 hp and 420 torque. The peak torque is in the 3,000 rpm range, so you'd need to rev it going up hills. But still..... However, I wouldn't want it for TT towing. But it should be capable of towing ultra-light TTs. Here's a link to the story: How GM Squeezed 420 Lb-Ft of Torque From the GMC Sierra's Four-Cylinder
 

DonTom

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I continue to be amazed at the power truck makers get out of smaller engines.
What amazes me is they don't design any LARGE four cylinder RV / light truck engines.

If Harley can (and has) make a large two cylinder engine that is so smooth you "cannot even tell you're on a motorcycle" and meets all the smog requirements, why can't somebody do the same with an RV engine with four cylinders?

When Harley first designed the M8 engine in 2017, it had 100% balancing and was way too smooth. The fix was 75% balancing so riders could tell they were on a motorcycle:

"When an engine with complete vibration cancellation was tested, riders rejected it; some vibration is an essential element of Harley’s unique feel. "

I would think that would be very efficient in an RV. Say a 7.5L four cylinder gasoline engine. It should have a lot of torque along with an extra good MPG. Should be great for towing.

At least get down to six cylinders in a large engine.

-Don- Reno, NV
 

DonTom

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steveblonde

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Stick that bad boy in a Colorado lol
Gm is released the c8 z06 next week rumoured to have 600+ hp in a car that weights nothing
 

Ex-Calif

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As you all might gather I am a technologist, engineer and wrench turner. The only Road Sports I watch is Formula 1 - US GP F1 tomorrow.

For years they have been cutting the displacement and the cars keep going faster. Regenerative braking and electric motor assist is developed in this arena.

They push the limits, nothing practical for a road car but the technology is incredible. 1.6L V6 and about 1000hp... Of course the torque curve isn't much use for an RV - LOL...

PS - I lied. I also watch Australian Super Cars. That crap is insane.
 

DonTom

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A large engine with 6 cylinders is already here
I don't follow what they do with diesels. I never owned one.

But why can't they make large gasoline engines with less cylinders?

There was a time when more cylinders meant a smoother ride. But these days, all it means is more moving parts for nothing and less efficiency.

-Don- Reno, NV
 

Utclmjmpr

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Usually the downside of a diesel engine is weight,, the high compression ratio needs very strong parts to handle internal pressures that are created,, thus a heavier overall weight..>>>Dan
 

Gary RV_Wizard

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But why can't they make large gasoline engines with less cylinders?
How big do you want? 230-300 cubic inch in-line 6's used to be common back in the day. The Dodge Power Wagon of the 40's & 50's was a beast that could haul or move most anything - I saw one equipped as a tow truck pull a loaded semi truck/trailer up over a mountain.

The major drawback to large cylinders is the inertia of a large piston. Remember that the piston has to stop and reverse direction 20-50 times each second. A big piston and its connecting rod have a lot of inertia and make that a mechanical challenge unless the rpms are kept very low. More smaller pistons are easier to engineer and more reliable over the long term.

Now powertrain engineers get more power from less displacement and use more gears to make the power available and useful.
 

DonTom

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A big piston and its connecting rod have a lot of inertia and make that a mechanical challenge unless the rpms are kept very low.
Yes, and when the engines are large the RPMs are low. That is what I like, low RPM engines that have power.

How big do you want? 230-300 cubic inch
In an RV, I would like a large six cylinder low revving engine above 8.2L/500 CI. IMO, that is where they should start with the mid to larger RVs.

-Don- Reno, NV
 

Alontheway

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Blowing 5-30 psi into an engine intake does wonders for power! Heck, even blowing in zero psi would make a difference over an engine having to suck air in.
I had a cummins and would not push it past 18psi for durability reasons, but guys would tweek their truck to blow in 40, 50, 100 psi and make incredible power, 1,000 horse power was possible. The downside was the engines wore out pretty quick.
Gas or diesel, it doesnt matter, it's the air, the main fuel source for engines, that makes power and torque. It is just that diesel engines are not worth a flip without a turbo so are known for turbo chargers.
I would not hesitate to tow big with a truck, 4 banger or not, that put out this kind of torque.
 

Gary RV_Wizard

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The small displacement engines just have to rev up a lot higher to produce the Hp, even witha turbo charger. That means more wear if they have to do it all the time, but most routine driving doesn't need continuous high Hp. Towing an RV, however, does mean a big increase in Hp demand, even on the level. Towing on a weekend trip is no big deal, but towing every day is a lot of work for a small engine. The big diesels trade a big displacement (and weight) to gain low rpms and a long operating life.
 
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