350 HP ICE vs. 350 HP Diesel?

Daveinet wrote:

hardtobe wrote:
yes but we are not talking cordless impact wrenches.What gas people fail to undertstand here is putting a 410HP/500LB gas engine in a 34000(net) diesel pusher is pure nonesence and not feasable FOR SEVERAL reasons.If it was feasible and do the job(which it will not) then one would see this done all day long

If these so called reasons exist, why do you continue to not be able to actually verbalize those reasons.

You will need to support your reasons with scientific fact. So far all you have done is play trial lawyer, with hyped emotion, rather than bringing real evidence to the table.

Yes, please list the SEVERAL reasons why it is not FEASABLE and WILL NOT WORK. Note, those are your words after letting us know how little we understand, you did not say desirable or unreliable...

hardtobe wrote:
yes but we are not talking cordless impact wrenches.What gas people fail to undertstand here is putting a 410HP/500LB gas engine in a 34000(net) diesel pusher is pure nonesence and not feasable FOR SEVERAL reasons.If it was feasible and do the job(which it will not) then one would see this done all day long

If these so called reasons exist, why do you continue to not be able to actually verbalize those reasons.

You will need to support your reasons with scientific fact. So far all you have done is play trial lawyer, with hyped emotion, rather than bringing real evidence to the table.

As far as suggesting why this has not been done, you seem to have forgotten the UFO, which is a 26,000 chassis, on a gas engine with only 338 HP. Talk to any of the owners, and they are very satisfied. Proportionally the Hemi in a coach weighing 4Klbs more is actually a little better.

I just have to put in one more jab and then I am done with this thread. I once had a high out rice burner motorcycle that would blow the doors off a Harley. I finally got a chance to ride the big Harley and I come away with "now that's a motorcyle" because you could put in in gear and go and didn't have to constantly shift because the Harleys torque was spread over a lot bigger range of rpms, making it a pleasure to drive and who cares about the quarter mile as a person drives a lot more than running the quarter mile. There are irrigation pumps that use the automotive engines that run on Nat gas. They usually run in the 1800 rpm range and not the 4500 to 6000 that gasser people talk about. But to each their own and happy that the gasser people are happy with their gasser. But I am sticking with the diesel.;)

All a classical example of "mines bigger than yours"....!!!!:E

hardtobe wrote:

rgatijnet1 wrote:

Daveinet wrote:
Seems there is a failure to understand gearing as it relates to RPM and torque. If you have forgotten high school physics, the the torque is the inverse of the gear ratio. So if you divide the gearing by half, you double the torque.

So very simply, if the engine is turning twice as fast, the gearing doubles the torque for the same RPM output. Example: Your diesel is rated 1200 ft-lbs at 1500 RPM. My 502 is 600 ft-lbs at 3000 RPM. Since my engine is turning twice as fast, it has to be geared down to 1500 RPM. 2:1 gear ratio. That gearing of 2:1 will double the torque.

Your drivetrain goes through multiple stages of gearing to achieve road speed. If the source engine is designed to spin twice as fast, it will be geared down twice as much to achieve the same road speed. This extra gearing multiplies the torque.

Some of the DP people seem to have trouble understanding torque. Like you mention, torque has everything to do with gearing, not HP. For instance you can buy a cordless impact wrench that puts out 1000 ft. pounds of TORQUE to tighten or loosen lug nuts. Total motor HP of the cordless driver might be 1HP but the torque is huge, due to gearing. :)

yes but we are not talking cordless impact wrenches.What gas people fail to undertstand here is putting a 410HP/500LB gas engine in a 34000(net) diesel pusher is pure nonesence and not feasable FOR SEVERAL reasons.If it was feasible and do the job(which it will not) then one would see this done all day long

I would opt for that if I were in the market for a coach that heavy. Especially if they could equip it with a very small supercharger and maybe some regenerative braking to offset the lack of that exhaust brake. Why would it not do the job out of curiosity? I'm not a complete fool and I know the reasons why one would want a full DP CHASSIS but why would a Gas engine with enough HP not do the job?

Shoot, Spartan is looking at gas chassis now due to demand.

rgatijnet1 wrote:

Daveinet wrote:
Seems there is a failure to understand gearing as it relates to RPM and torque. If you have forgotten high school physics, the the torque is the inverse of the gear ratio. So if you divide the gearing by half, you double the torque.

So very simply, if the engine is turning twice as fast, the gearing doubles the torque for the same RPM output. Example: Your diesel is rated 1200 ft-lbs at 1500 RPM. My 502 is 600 ft-lbs at 3000 RPM. Since my engine is turning twice as fast, it has to be geared down to 1500 RPM. 2:1 gear ratio. That gearing of 2:1 will double the torque.

Your drivetrain goes through multiple stages of gearing to achieve road speed. If the source engine is designed to spin twice as fast, it will be geared down twice as much to achieve the same road speed. This extra gearing multiplies the torque.

Some of the DP people seem to have trouble understanding torque. Like you mention, torque has everything to do with gearing, not HP. For instance you can buy a cordless impact wrench that puts out 1000 ft. pounds of TORQUE to tighten or loosen lug nuts. Total motor HP of the cordless driver might be 1HP but the torque is huge, due to gearing. :)

yes but we are not talking cordless impact wrenches.What gas people fail to undertstand here is putting a 410HP/500LB gas engine in a 34000(net) diesel pusher is pure nonesence and not feasable FOR SEVERAL reasons.If it was feasible and do the job(which it will not) then one would see this done all day long

Daveinet wrote:
Seems there is a failure to understand gearing as it relates to RPM and torque. If you have forgotten high school physics, the the torque is the inverse of the gear ratio. So if you divide the gearing by half, you double the torque.

So very simply, if the engine is turning twice as fast, the gearing doubles the torque for the same RPM output. Example: Your diesel is rated 1200 ft-lbs at 1500 RPM. My 502 is 600 ft-lbs at 3000 RPM. Since my engine is turning twice as fast, it has to be geared down to 1500 RPM. 2:1 gear ratio. That gearing of 2:1 will double the torque.

Your drivetrain goes through multiple stages of gearing to achieve road speed. If the source engine is designed to spin twice as fast, it will be geared down twice as much to achieve the same road speed. This extra gearing multiplies the torque.

Some of the DP people seem to have trouble understanding torque. Like you mention, torque has everything to do with gearing, not HP. For instance you can buy a cordless impact wrench that puts out 1000 ft. pounds of TORQUE to tighten or loosen lug nuts. Total motor HP of the cordless driver might be 1HP but the torque is huge, due to gearing. :)

OhhWell wrote:

hardtobe wrote:

Daveinet wrote:
Total weight the powertrain is pulling up the hill. It was intended as a point of reference. The 502 is not stock. If I run in 3rd, my drive wheel torque is the same as a DP with 1200 ft-lbs of torque.

Per the 410 HP hemi, you could easily put it in a coach weighing 30K+ lbs. It would accelerate fine. If you measure performance with your speedometer, it would hold speed on the the hills. That is indisputable fact. But so that no one is mislead, you would probably want to gear it, so it was turning about 3K RPM at 65 mph, which is very similar to how the early 80s 454s were setup. A setup like that would work just fine. 3K RPM would give you the same amount of drive wheel torque as a diesel turning 1500 RPM with 860 lb-ft of torque - a pretty common spec amongst large DPs. (assumption of both engines running in top gear)

I call BS. on 1200 lbs of torque in the 502? puts u at like 950-1000HP

At the wheels... goodness.... :S
At the wheels!

your correct I missed that all together my bad.

Seems there is a failure to understand gearing as it relates to RPM and torque. If you have forgotten high school physics, the the torque is the inverse of the gear ratio. So if you divide the gearing by half, you double the torque.

So very simply, if the engine is turning twice as fast, the gearing doubles the torque for the same RPM output. Example: Your diesel is rated 1200 ft-lbs at 1500 RPM. My 502 is 600 ft-lbs at 3000 RPM. Since my engine is turning twice as fast, it has to be geared down to 1500 RPM. 2:1 gear ratio. That gearing of 2:1 will double the torque.

Your drivetrain goes through multiple stages of gearing to achieve road speed. If the source engine is designed to spin twice as fast, it will be geared down twice as much to achieve the same road speed. This extra gearing multiplies the torque.

hardtobe wrote:

Daveinet wrote:
Total weight the powertrain is pulling up the hill. It was intended as a point of reference. The 502 is not stock. If I run in 3rd, my drive wheel torque is the same as a DP with 1200 ft-lbs of torque.

Per the 410 HP hemi, you could easily put it in a coach weighing 30K+ lbs. It would accelerate fine. If you measure performance with your speedometer, it would hold speed on the the hills. That is indisputable fact. But so that no one is mislead, you would probably want to gear it, so it was turning about 3K RPM at 65 mph, which is very similar to how the early 80s 454s were setup. A setup like that would work just fine. 3K RPM would give you the same amount of drive wheel torque as a diesel turning 1500 RPM with 860 lb-ft of torque - a pretty common spec amongst large DPs. (assumption of both engines running in top gear)

I call BS. on 1200 lbs of torque in the 502? puts u at like 950-1000HP

At the wheels... goodness.... :S
At the wheels!