danmas Dan Masters Alcoa, Tennessee (578 posts) Registered: 10/28/2007 12:11AM Main British Car: 1974 MGBGT Ford 302 |
Horsepower is horsepower, right?
Reading through a DOD report on an analysis done by the Navy on captured WWII German U-Boats, I ran across a description of one of the Diesel engines used.
430 horsepower. Doesn't sound like much does it? A good Chevy 350 can easily top that. Ah, yes, but.....that was at 375 rpm! Doing the math, that works out to be 6,020 ftlbs!!!! Holey moley! That would smoke some tires. Horsepower and torque numbers without the rpm don't mean much, do they? |
kstevusa kelly stevenson Southern Middle Tennessee (985 posts) Registered: 10/25/2007 09:37AM Main British Car: 2003 Jaguar XK8 Coupe 4.2L DOHC/ VVT / 6sp. AT |
Re: Horsepower is horsepower, right?
The TKO or Tremec will not stand that kind of torque. Maybe if we add ZZDP and silicone brake fluid, the steering can survive with just oil instead of grease.. Did we miss any controversity? Have a safe and Happy New Year.
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Re: Horsepower is horsepower, right?
Different vehicles benift form different engines.
These are the engines my brother builds: [www.carcraft.com] [www.thunderv12.com] The stock engine makes 630ft lbs at 2400 rpm which is only 275hp....stock........ People say a 302 could do that if reved to the high rpm. These are not engines for light weight sports cars. Would you want an over reved 302 In these? [6066gmcclub.com] [www.thunderv12.com] [www.ssrfanatic.com] [files.conceptcarz.com] [www.carbodydesign.com] [media.motortopia.com] [i1.ytimg.com] |
BMC Brian Mc Cullough Forest Lake, Minnesota, USA (383 posts) Registered: 10/30/2007 02:27AM Main British Car: 1980 MGB '95 3.4L 'L32' SFI V6, GM V6T5 & 3.42 Limi |
Re: Horsepower is horsepower, right?
---Anybody know if you can mate a T5 to one of these engines?---
I know we have the technology and skill. It will be an unholy mating and who knows what would become of it but if you are willing to pay... -Here, hold my drink and watch this! -BMC. Edited 1 time(s). Last edit at 01/02/2014 12:10AM by BMC. |
danmas Dan Masters Alcoa, Tennessee (578 posts) Registered: 10/28/2007 12:11AM Main British Car: 1974 MGBGT Ford 302 |
Re: Horsepower is horsepower, right?
A top fuel dragster engine puts out an estimated 8,000 horsepower, and is limited by the rules to 8,400 rpm. Doing the math, that equates to 5,000 ftlbs.
Holey moley! I have a hard time wrapping my head around that. |
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roverman Art Gertz Winchester, CA. (3188 posts) Registered: 04/24/2009 11:02AM Main British Car: 74' Jensen Healy, 79 Huff. GT 1, 74 MGB Lotus 907,2L |
Re: Horsepower is horsepower, right?
Burn up enough "calories", and any dyno will sweat. Nitromethane is the mother them for piston engines, as long as your afr is around 2/1 ? Cheers, roverman.
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BlownMGB-V8 Jim Blackwood 9406 Gunpowder Rd., Florence, KY 41042 (6470 posts) Registered: 10/23/2007 12:59PM Main British Car: 1971 MGB Blown,Injected,Intercooled Buick 340/AA80E/JagIRS |
Re: Horsepower is horsepower, right?
Turning liquid directly into smoke, one combustion chamber full at a time. My oh my. Can you say "Hydrolock"?
Jim |
Re: Horsepower is horsepower, right?
The Regency Hotel in Atlanta has a restaurant that the whole seating area (many tons of concrete and steel) rotates one revolution per hour. Driven by a 1HP elec motor.
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DiDueColpi Fred Key West coast - Canada (1366 posts) Registered: 05/14/2010 03:06AM Main British Car: I really thought that I'd be an action figure by now! |
Re: Horsepower is horsepower, right?
A friend of mine, Dave, runs a top fuel dragster that his son drives.
He sent me an interesting list of facts that he never really considered before. He generally looks at every pass as a huge economic event. As a top fuel engine runs at it's stoichiometric mixture of 1.7 to 1 (for nitro) it compresses the mixture into a near solid at full throttle. Spark plugs run at roughly 44 amps per and are completely melted at 1/2 track. The engine diesels for the rest of the run. The only way to shut the engine down is to cut off the fuel flow. The cranks twist so badly during the run that the cams are generally ground to compensate for the rear cyls out of wack timing. Some cams differ by 20 degrees from front to back. The one spec that woke me up was the fact that the engine only made 520 or so revolutions during a run! The other was that the exhaust exiting the headers provides around 1100 lbs of downforce. My engines tend to last a little longer. But they come up a little shy on horse power. cheers Fred |
Dan Jones Dan Jones St. Louis, Missouri (280 posts) Registered: 07/21/2008 03:32PM Main British Car: 1980 Triumph TR8 3.5L Rover V8 |
Re: Horsepower is horsepower, right?
> Horsepower and torque numbers without the rpm don't mean much, do they?
Engine torque needs RPM to be meaningful (so you can convert it to HP). If you know HP (specifically the average HP between shift points), you don't need RPM to determine the acceleration. Torque is the rotary equivalent of force and is what accelerates a car but it's the torque at the rear wheels that accelerates the vehicle, not the torque at the crankshaft. However, horsepower (at the crankshaft) is the measure of how much RPM can be traded for rear wheel torque via gearing. If two engines have the same power but different torque, they will still accelerate the same vehicle at the same rate if the gearing for each is optimal. The engine with less torque will have to spin at a higher RPM to do so. Gearing is the reason you accelerate harder in 1st gear than you do in 4th or 5th (there's also an aerodynamic drag effect but that is relatively less important for the purposes of this discussion). It's the overall gearing provided by the the transmission, rear end, and tire diameter that is important and this also assumes the same average power over the RPM spread between gears, not just equal horsepower peaks. > It's a calculation of the 2 but I can't remember what it is Horsepower is the rate of producing torque, so the two qualities are functions and directly related to each other: HP = (TQ*2.0*PI*RPM)/33000.0 TQ = (33000.0*HP)/(2.0*PI*RPM) where: TQ = torque in ft-lbs HP = power in horsepower RPM = engine speed in revolutions per minute PI = the mathematical constant PI (approximately 3.141592654) Note: 33000 = conversion factor (550 ft-lbs/sec * 60 sec/min) In general, the torque and power peaks do not occur simultaneously (i.e. they occur at different RPMs). However, since the curves are functions of each other, the curves will always cross at 5252 RPM when the units are torque in ft-lb and power is in Horsepower. There's nothing magic about that number and it will have a different value for different units. If you assume power in Watts and torque in Newton-meters, you'll get a different cross-over RPM. Dan Jones |