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An interesting article and accompanying videos at the following site-https://www.roadandtrack.com/new-cars/car-technology/a30753008/fords-73-liter-v-8-can-make-600-naturally-aspirated-horsepower-with-basic-mods/?source=nl&utm_source=nl_rdt&utm_medium=email&date=020420&utm_campaign=nl19309505
 

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An interesting article and accompanying videos at the following site-https://www.roadandtrack.com/new-cars/car-technology/a30753008/fords-73-liter-v-8-can-make-600-naturally-aspirated-horsepower-with-basic-mods/?source=nl&utm_source=nl_rdt&utm_medium=email&date=020420&utm_campaign=nl19309505
No replacement for displacement

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If a 3.6 Pentastar makes 290hp, it would stand to reason that an engine twice the size can make twice the hp.

My question is why did they tune it so low in the first place?


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If a 3.6 Pentastar makes 290hp, it would stand to reason that an engine twice the size can make twice the hp.

My question is why did they tune it so low in the first place?


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I think they tuned it for long life and more torque at lower RPMS as well as for fuel efficiency. Various things I have read seem to indicate they are really going for the commercial HD market with this engine. Their argument is reliability and on the job time and lower purchase cost more than outweighs the fuel cost hit by not going to a diesel. Remember most commercial companies are not in a position to flaunt the emissions law and cannot delete their trucks. I saw the trend several years ago when the new trucks that UPS were buying were gas that replaced the diesels. Fedex also is arriving at my house with fewer and fewer diesel powered Sprinter or Mercedes vans as they wear out and are replacing them with gas engined trucks. It strikes me that if anyone fully understands and analyzes the life cycle cost of various options it is people like UPS.
 

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If a 3.6 Pentastar makes 290hp, it would stand to reason that an engine twice the size can make twice the hp.

My question is why did they tune it so low in the first place?


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Agree with Howie on that one. Longevity more than likely. That's a lot of mass rotating, kind of like a semi engine. Pistons weigh like 40 pounds so turn it too fast and itll come apart.

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The 3.6 is considered a reliable engine by most accounts...just sayin’.

Reliability should come standard. If they have to de-tune it to make it reliable, is it really reliable?? I guess the marketing research for “really neutered this engine so it doesn’t fly apart” didn’t go over well. They marketed the old school push rod design the reason for being more reliable anyways.

If it is for efficiency, getting more power from the same displacement is usually a good sign that an engine is more efficient, all things being equal. Just look at the ED, I think it is a fair to say a well tuned truck is more fuel efficient (with more hp and tq) and more reliable. That might not be an apple to apple comparison, but I have tuned every gas vehicle I’ve owned for the last 15 years and always got better fuel economy as an added benefit.

Maybe they are sandbagging for future power upgrades?

I’m not a Ford guy, but if I was, would have been hoping for more. I guess that’s my only real point. Reminds me of the V-10 truck engines from Ford and Dodge, really seemed to miss the mark in the power department.


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There is more to reliability than just can the engine stand up to the power, its also can the drive train last 300k at the power level and how much maintaince well it need to survive there. Look at medium duty trucks and buses they have 6.7 and 8.3 Cummins with under 400 hp some under 300 hp. The big thing ford is pushing for is sales and corporations dont care if the truck has a 600 hp but they do care about reliability and low maintaince costs.
 

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There is more to reliability than just can the engine stand up to the power, its also can the drive train last 300k at the power level and how much maintaince well it need to survive there. Look at medium duty trucks and buses they have 6.7 and 8.3 Cummins with under 400 hp some under 300 hp. The big thing ford is pushing for is sales and corporations dont care if the truck has a 600 hp but they do care about reliability and low maintaince costs.
I’m an engineer and reliability manager; my site had a record year last year at $60M in revenue. I know a little about reliability of equipment.

All I am saying is that if I was personally looking to buy a big gas truck because I didn’t want a diesel, I would be disappointed in the numbers that engine puts out. I understand big corporations might not care; but the diesel torque wars are still raging, are big corporations driving that?


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The 3.6 is considered a reliable engine by most accounts...just sayin’.

Reliability should come standard. If they have to de-tune it to make it reliable, is it really reliable?? I guess the marketing research for “really neutered this engine so it doesn’t fly apart” didn’t go over well. They marketed the old school push rod design the reason for being more reliable anyways.

If it is for efficiency, getting more power from the same displacement is usually a good sign that an engine is more efficient, all things being equal. Just look at the ED, I think it is a fair to say a well tuned truck is more fuel efficient (with more hp and tq) and more reliable. That might not be an apple to apple comparison, but I have tuned every gas vehicle I’ve owned for the last 15 years and always got better fuel economy as an added benefit.

Maybe they are sandbagging for future power upgrades?

I’m not a Ford guy, but if I was, would have been hoping for more. I guess that’s my only real point. Reminds me of the V-10 truck engines from Ford and Dodge, really seemed to miss the mark in the power department.


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I agree with your comment about the Pentastar and I own 2. However given the service the Pentastar is put into I expect it spends its life operating at a much lower % of its maximum output than the Ford engine will when in a commercial vehicle.

I will say what I was trying to say a different way. Optimum tuning for an engine going into a commercial vehicle is different than optimum tuning for a Mustang or some individual consumers.

All the best,
 

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I’m an engineer and reliability manager; my site had a record year last year at $60M in revenue. I know a little about reliability of equipment.

All I am saying is that if I was personally looking to buy a big gas truck because I didn’t want a diesel, I would be disappointed in the numbers that engine puts out. I understand big corporations might not care; but the diesel torque wars are still raging, are big corporations driving that?


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Ford also knows individuals might be unhappy with the low (if you can call them that) power numbers so they leave some room to grow. Tuning with a naturally aspirated gasser usually doesnt make big power numbers so they intentionally left room in this engine.
 

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To me peak horse power means nothing. Sure a hemi makes 400+ hp.... at 6000 rpm. To me running at that rpm is not a good recipe for longevity. They upped the displacement to gain power at a lower usable rpm. All the custom tuning etc you do has its greatest affect at the peak of power curves which in an industrial application are likely never used. A more aggressive cam would definitely give more power etc. but it comes at the expense of shorter valvetrain life etc.

It makes complete sense to me why they did what they did. And im sure if it proves to be a solid base there will be many to build from it.
 

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I agree with your comment about the Pentastar and I own 2. However given the service the Pentastar is put into I expect it spends its life operating at a much lower % of its maximum output than the Ford engine will when in a commercial vehicle.
You make a good point. If the engine makes more power, in theory it would operate at a lower % capacity to achieve the same amount of output.


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You make a good point. If the engine makes more power, in theory it would operate at a lower % capacity to achieve the same amount of output.


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Yes, you are correct but that isn't the picture I was trying to get across. First, I should have said maximum design output. I was thinking about fatigue life of various engine components. AS I expect you know fatigue is a complex process and depends upon a lot of variables. However I will generalize that there is a stress level at or below which the fatigue life is extremely high and not an issue as stresses rise above that point the fatigue life goes down and then it starts to decrease very rapidly as stress levels rise further and can become very short. I don't know crap about the details of engine design, I am just a civil engineer with some structural engineering, material science, statics and dynamics courses in the distant past.

Given the above my thought process goes like this 1-A fatigue failure in an engine is a catastrophic failure and extremely expensive to repair and inconvenient for the owner. 2-Wear of an engines in the cylinders, cams, bearings etc is a gradual process that gives the observant operator signs that the engine is becoming in need of a rebuild/repair/replacement. Something an owner can plan for and organize. 3-Surely the design philosophy must be to avoid fatigue failures at the stress levels expected to be seen during the desired life of the engine. 4-If the stress levels rise above the design basis the fatigue life goes down and the risk of a catastrophic fatigue failure goes up. At some point the stress increases drastically reduce the life of the engine. I have no idea where that is on the Ford engine or any others. 5-Given the issues of weight and fuel mileage that are such a big deal nowadays and the much better analytical methods available I expect modern engines have less inbuilt surplus strength. 6-Therefore it is reasonable to expect that an engine that is designed to produce 300 hp and operate at 90% of that output 90% of the time will have a much longer life before a fatigue failure than that same engine tuned to 600 hp and operated at 90% of 600hp 90% of the time with the same basic internal parts.

I am now off this horse but perhaps Crash or someone with knowledge about how engines are actually designed can chime in.

All the best,
 
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