Diesel vs gas......................

[blt2ski]

OK folks, there have been a few to many diesel vs gas threads that have shall we say gone to "Hell and a hand basket"! So if all of you would put in you BEST, no flaming reasons for going gas vs diesel, pro and con, I will either leave your thread, or copy and paste pertinant info to the 4 posts of pro and con of diesel or gas. This can include the GM 8.1 vs Dmax or Ford V-8/10 vs PSD etc too.

Be real and honest in you answers, not hear say, flaming etc PLEASE!

If posts are good ones, I will leave, if inflamatory or trolling in nature, they will be deleted! I will get this stick'd to the top for future parusing for those that need this type of info.

Added 6-23-04

We are getting closer to answers I am looking for etc.

Stuff like Ken's - T-Bone posts are good. There are a few others of you that have not posted, some with a 9 point question and answer type to figure out how you went with one or the other. If you are one of those, PLEASE repost in this thread. I may have to look up whom has done this and PM you, but if you think this is you, you now know what to do.

Also, for those of you with $ per gallon for either fuel right now, I would prefer to see a post with ...."in my area, diesel is typically .10 less than unleaded" then explain your numbers. As currently in the Seattle area, diesel and unleaded are any where from 2.05 -2.30 per gallon, with mid test .10 more and premium about .20 more, with equal high low splits. Two weeks ago those prices were upwards of .30 -.40 per gallon more. people were posting $ per gallon that were for me. "I wish" If someone is reading your post a year from now, they may want to know where your paying 1.65, when the price of fuel is over $3 per gallon. Let's keep prices out of it if possible.

Bert and tin tipi, got into a good discusion on the pros and cons of RPM's, drive train etc. I would prefer to NOT see the quote of the other in responding threads, maybe just write a quick wording of re tranny gearing, instead of the whole 40 words or so in that paragragh, so the repsonse is shorter if possible quicker and easier to read etc.

I have deleted some 15+/- posts, that were off topic etc. Please note, I am trying to keep this at the top, as the ONLY gas/diesel thread in this area. So if one is trying to decide, we do not have to go thru this BS any more. As such, I will be deleting ANY future posts close to resembling this type of topic. I may have to change "this" title to a better one, if one has a better sounding title, to be more positive, better claification, let me know here, or in a PM/e-mail, what ever you feel most comfortible with.

Again thank you for all of you that are keeping responses positive, etc.

Also we could use a few more positive reasons to go gas, as many can see I have both gas and diesel, both have a place! Both have positive reasons to buy that fuel, lets keep the threads etc to that purpose only!

Marty

[Madhatter1]

Everyone wants to point out what others have missed so here I go. If you have a high rpm gas engine the peak torque will be at or near the peak RPM and you can use that calculation to find peak torque. The peak tourqe of most diesels is before the peak HP and RPM. Since we are using tanks and aircraft as examples I will use the 5.9 CTD's on my boat. Rated at 270HP at 2600RPM you get 545lbs torque. If you take the HP numbers from the chart (I do not still have this but remember the peak torque from when I did this in 98) the peak torque is 760+lbs around 1600 RPM. I was considering Yanmar engines of a higher HP but they run at 3600rpm and produce very little torque untill over 2000RPM. Sooooo, what does this mean in the real world? My 66 Hatt planes off no problems with dirty props and Yanmar powered boats make lots of black smoke but can't get to the power RPM with dirty props. Big torque numbers low in the range is what gets loads moving with ease. Some will argue all day that a gas V-10 pulls big loads as well as any Diesel but we all know that is not true. My 08 6.7 will run away from my 05 5.9 unloaded with all that Hp in the high RPMs but hooked up to my trailer the only difference in performance is from the new 6 speed tranny. High RPM HP is useless for towing big loads. OK, beat me up now.

[dubdub07]

The engine has torque without the gears or transmission. The gears can create more torque but is limited to how fast it is delivered to the transmission based on the horsepower. Also, you can create a ton of torque from any motor with the tranny and rear end, but that effects top speed. Once again, the screaming of the HEMI. You need engine torque combined with decent hp to get a big load moving at a decent rate.

This applies to your steam engine as well. The torque exists through the leverage in the arms connected to the wheels. A steamer is a piston on a rod.....like internal combustion, maybe?

You can google this all and it will tell you. I am not making it up.

[Rvndave]

Well torque is what turns my wheels. You can pick whichever number you like to satisfy what you want to justify is the best engine. I will run with the torque numbers as this is again what turns my wheels. I use the horsepower to determine where my power band is. As I shift with a heavy load I keep above the highest RPM where there is the most torque and below the RPM where maximum horsepower is.

I believe only torque can be measured, horsepower is only a calculation of torque and RPM. Without knowing torque and RPM you can not obtain horsepower. Correct me if I am wrong.

I agree on the point made as the air gets thinner the naturally aspirated gas engine is going to lose large amounts of power.

[BertP]

Very well stated.

Bert

[Hannibal]

Why do we get all torqued up about torque and horsepower. Horsepower (in our application) is simply the rate at which we apply our available torque. The faster our engine can apply as necessary, the more we can multiply our available torque through gear reduction. Since the math comes into play, and the math does work, you can conclude that horsepower is the final and first part of the equation necessary to determine how much torque you'll need for a given road speed at your desired rpm. Otherwise, you simply calculate how much horsepower you need and let it roar in 2nd to multiply the lesser torque by 1.67 into equal torque at the rear axle as I do with the little Hemi. It works. Other forms of horsepower are used as examples to show that torque is not necessary in every application to move the load from point A to point B in a given amount of time (horsepower). A Steam locomotive doesn't produce the first hint of torque. It doesn't twist the wheels. It pushes them half round one side at a time. The example makes the point that horsepower is the number necessary for moving the load at a given speed. Torque and rpm is simply how we reach that number in our application. Without torque, all the rpm available won't move the load. Without rpm, all the torque in the world won't move the load. The two together are known as horsepower. We find a happy balance between the two based on several factors. Mostly our inconsequential "perception" of what is screaming or lugging.

[dubdub07]

Ace! wrote:
I put the smiley/wink in there because I realize what's true and not in regard to the engines, and I thought the arguments back and forth were as funny as my post, but maybe my post was even a little funnier.

Sorry about that, I don't get the images because I am at work, they lock out certain aspects of web pages.....I am actually surprised they haven't locked this site! These forums are great!!!!

[Ace_]

I put the smiley/wink in there because I realize what's true and not in regard to the engines, and I thought the arguments back and forth were as funny as my post, but maybe my post was even a little funnier.

[dubdub07]

Ace! wrote:
And that my friends is why the Ford Triton V10 is better than the competition's diesels 😉

Dude, that is not true. IF ANYTHING, it would be an ample substitute. Pull a mtn pass @ 7500 ft and tell be again how superiour an air aspirated motor is without air. And he is wrong, so don't quote what he says.....

[Ace_]

And that my friends is why the Ford Triton V10 is better than the competition's diesels 😉

[BertP]

dubdub07 wrote:
*********"So we now know that horsepower and torque are basically two different views of the same thing - change one and the other most also change."*********

To show that HP and T are not the same thing, consider the situation where we have zero rpm like we might with an electric motor. You can increase the torque output of that motor until the cows come home or you burn out the motor - whichever comes first - and as long as the motor does not turn, you will have zero HP. You can hve all the torque in the world but if the motor doesn't turn, you have zero HP.

Bert

[BertP]

The max torque of the Abram's engine is just under 400 lb ft as Marty stated. To use the formula you provided:
HP = T * rpm / 5252
HP = 2750 * 22,500 / 5252
HP = 11,781

I think that we can both agree that the engine in the Abrams does not produce anywhere near 12,000 HP! Where the confusion comes in is that the 2750 lb ft of torque is measured at the output of the power pack which includes both the engine and a set of step down gears. The engine itself produces:

HP = T * rpm / 5252
T = HP * 5252 / rpm
T = 1500 * 5252 / 22,500
T = 350

Bert

[dubdub07]

The Honeywell AGT1500 gas turbine engine is the main powerplant of the M1 Abrams series of tanks. The engine was originally made by Lycoming and is now built by Honeywell Aerospace. Its peak power is 1,500 hp (1,120 kW) and peak torque is 2,750 lb-ft (3,754 N-m).[1] The engine can use a variety of fuels, including jet fuel, gasoline and diesel.[1]

The AGT engine is built in Anniston, Alabama at the Anniston Army Depot.


For you tank lovers.........check the torque rating. This a turbine motor...so does that spell two arguements with one quote?

[dubdub07]

BertP wrote:
Yes, this is basic stuff. But, your formula HP = T * rpm / 5252 assumes that you have rpm. In our gas and diesel engines, yes you have rpm. My point is that HP also exists in situations where there is no rpm: jet engines, rocket engines, steam engines, horses, us, etc, etc.

Secondly, your assertion that if you chage one of HP or torque then the other must change is not correct. Without reference to rpm, no such claim can be made. If you claimed that, at a given rpm, if you change HP or torque then the other will change then you would be correct. Without that reference to rpm, though, it is impossible to determine what, if any, change is caused in one of those values by a change in the other.

Dynos also do not always measure torque. Chassis dynos, for example, measure HP and calculate torque. Other types of dynos measure other valuse and calculate both HP and torque.

Bert

Can a human have HP?

[dubdub07]

*********"So we now know that horsepower and torque are basically two different views of the same thing - change one and the other most also change."*********

[dubdub07]

I am not making this up. What in the world. We are a bunch of old guys talking about truck motors and now we are jumping into spacecraft! It is very easy to find the source documents on this stuff, I prove it to you guys and you are STILL in disbelief....wow.
I am now banging my head on a wall.

I think you have it backwards; tank motors had about 500hp and produced lots of torque.