quote Originally posted by Exotic Rida: hell a viper a 8.3 liter!!! thats a lot of DISPLACEMENT!!!!! but only 500 h.p.?? why ????? BAD DESIGN!!!!! not saying it wont get the job done but too much engine for so little hp

Bad design? Perhaps. Dodge wants to keep the nostalgia of a pushrod motor. Imagine if a viper was a 40 valve DOHC?

quote Originally posted by crzyone: Back in the turbocharged days of F1 they had 1.5L engines making 1000hp with 60psi of boost. Not like they had a displacement restriction, thats just the lightest most powerful combination they could make. You can't tell me those engines arn't reliable.

Those engines weren't in their infancy years, ('77-'81)

Some of the Old Skool "displacement means power" guys need to give it a rest.

I'll take a small displacement forced induction motor over a large displacement NA motor any day.

A turbocharged motor can make 500hp and get good fuel economy, big displacement motor can not. Dodge is trying with the new hemi's with displacement on demand, but they are still only getting 20mpg.

Yes, I know why Nascar outlawed the hemi, its because it had an unfair advantage. Nascar is all about everyone having the same setup. One manufacturer can not have a different type of engine in their car. It would be like putting dohc heads on a nascar today, it wouldn't be allowed because it would offer an advantage. They need rules or teams will do anything they can for more power. But you knew that, and assumed that I didn't.

Pushrod engine< Hemi<Dohc

A few points.

A F1 engine is constantly being rebuilt race after race. Try and run one for 60,000 miles with little to no maintenance other than an oil change and see how reliable it is.

A boosted small displacement engine can produce more power than a n/a larger displacement engine, but the smaller engine has to work a lot harder to do so. As you increase the load the stress on the engine increases dramatically. To tow a heavy trailer up an incline the smaller engine has to run closer to it's max capacity to attain the same results leading to premature engine wear.

Boost creates alot of excess heat (turbos especially). This heat has to be gotten rid of somehow. Most smaller boosted engines only have to operate under max boost for a few seconds at a time, and therefore the cooling systems in theese cars are designed accordingly. To maintain max boost for the time needed to tow a trailer (depending on where you are going that could be hours) the cooling system would need to be larger than the space available in most small cars. Your turbo'd 4banger would quickly overheat and die. Also most small turbos don't have a duity rating intended for continous max boost.

Finally THERE IS NO REPLACEMENT FOR DISPLACEMENT. If you apply the same level of technology to a larger engine as to a smaller engine, the larger engine would win...period.

Some factors:

Piston ring linear speeds against the cylinder wall are limited. High-rpm race motors can do so because they're really short strokes, so the piston rings actually aren't moving much faster.

Pushing force against the piston is caused by expanded air, mostly nitrogen, that expansion is caused by heat from burning oxygen and fuel. The more mass of air that can be crammed into a cylinder the more push.

The further away from the crank centerline the connecting rod journal is, the more leverage turning the crank, but that also means more stroke, so lower RPM limits to keep the ring speeds down. Also, bearing side forces increase dramatically with larger strokes, limiting RPMs before the oil film shears.

The bigger the piston area (larger diameter) the more push assuming you can get more air mass into the cylinders.

So, a short stroke large bore engine with some way to cram more air mass in, like a turbo or supercharger, would be the way to go for ultimate horsepower, it would seem to me.

Oh, car engines are designed and rated to produce peak horsepower less than 1% of their service lives, but industrial motors are rated to produce peak power all of their service life. Typical car engines will last around 2000-3000 hours, large industrial motors are designed to last much longer. That's why when you see automotive-derived industrial engines, like GM's 3.0 L L4 sold for welding applications, they're typically rated for something like 40 horsepower instead of the 150-175 that they could easily do in a car.

JazzMan

JazzMan

quote Originally posted by JazzMan: Some factors: Piston ring linear speeds against the cylinder wall are limited. High-rpm race motors can do so because they're really short strokes, so the piston rings actually aren't moving much faster. The further away from the crank centerline the connecting rod journal is, the more leverage turning the crank, but that also means more stroke, so lower RPM limits to keep the ring speeds down. Also, bearing side forces increase dramatically with larger strokes, limiting RPMs before the oil film shears. JazzMan

i dont understand the specific logic behind, "speeds are limited" the short strokes of a engine with high RPMs will make them spin much much FASTER in reality. At high rpms, the pistons are moving up and down very, very fast, but they arent going much more DISTANCE than an engine with low RPM's and a long stroke, even when the piston is moving much SLOWER.

for this to seem logical to me form my perspective the statement should read-

Piston ring linear distance against the cylinder walls are limited. High-rpm race motors can do so because they're really short strokes, so the piston rings actually aren't moving much more distance.

I am only a high school student, i have taken physics,and Advanced Algebra only. They are fresh in my head, but i dont know as much as engineers, but i read too much on motors and cars, i have studied at MSOE for a week in a crash course on engineering. So many people are commenting on how cars motors are built and how the behave with out proof of their conclusion, im sure the best way to resolve this issue is through the scientific method, through actual races, or through pumping out a mathmatical simulation. All I know is that the actual torque curve and final drive not # of cylinders will dictate the peformance of the cars. There is no HP vs TQ; they are both simply dirivatives of each other. It's more af analysis of how they are placed in relation to each other on the TORQUE CURVE.

Sure back in the 60s/50s people managed to make cars perform extremely well out of their garage by shoving more cubes in thier engines, but with the advant of improved technology and improved engineering and manufacturing techniques (technology) motors are able to produce numbers limited to motors by their displacement. but keep in mind not all motors are created equal, some aren't well engineered/manufactured to deliver their theoretical potential some have differnt tolerences and such, some are built/engineered well. this might explain why hand built small displacment motors can be more powerfull other mass built motor of bigger or the same displacment. the desing of the sytem makes a huge difference.

So the trucks torque curve combined with its gearing is well suited to towing becuase its desinged that way. The hondas torque curve is difficult to really analyze lightly becuase the turbos and forced induction really make this thing complicated; but if its setup to be modded with more high end power and not much more torque its powerfull yes, but the gearing becomes an issue, the cars is orginally geared to be an economy car, sure there are ways of changing the gearing but these cars are FWD, the geraing isnt as flexable as the rwd trucks live axle and its not always done on hondas, so the towing concept might not work well with the civic becuase the motor will work harder with a lower final drive of a economy trans not multiplying the torque as much as the ram's does.

This is my understanding of the situation. If it's flawed tell me so their isn't just another false knowlendge in database of bad assumptions in the hot topic of horsepower and torque on the internet. This topic is really getting crazy, everyone knows everything but noone knows the same thing

teenage know-it-all rant is officialy over

[This message has been edited by FieroWannaBe (edited 07-30-2005).]

Why would anybody say a 350HP v8 woudl beat a 400hp 4cylinder? I mean, obviously (And I've seen it done a million times) you can't take the gearing and the setup for the curve of the other engine and expect it to be faster in the other engine, but once you get a drivetrain setup that takes advantage of the specific motor, it will win.. Cylinders are pretty inconsequential for point of a race.. Torque does not 'win races'.. Was this said in a 60's commercial or something? I don't care if you have 1000 ft/lb if it runs out of breath in a second.. Sorry if that has been previously said in the thread.

I'm still wanting to see someone pull the load mentioned, with a 4 banger, up a hill, rolling start or not.

Kevin

quote Originally posted by Lambo nut: I'm still wanting to see someone pull the load mentioned, with a 4 banger, up a hill, rolling start or not. Kevin

Well for one thing I'm not going to go out of my way to build a car for the sole purpose of pulling a load up a hill.. Obviuosly trucks are meant to do that..

quote Originally posted by JohnnyK: Why would anybody say a 350HP v8 woudl beat a 400hp 4cylinder? I mean, obviously (And I've seen it done a million times) you can't take the gearing and the setup for the curve of the other engine and expect it to be faster in the other engine, but once you get a drivetrain setup that takes advantage of the specific motor, it will win.. Cylinders are pretty inconsequential for point of a race.. Torque does not 'win races'.. Was this said in a 60's commercial or something? I don't care if you have 1000 ft/lb if it runs out of breath in a second.. Sorry if that has been previously said in the thread.

Thats what i tried to say, but I said to much in saying it.
its all in geraing and curves, the right setup will win.
noone knows for sure what a car is capable of just by saying the motor is a 400hp 4cyl, or a 350hp v8 you need the other variables too,
let go of the bias and asses the situation, look at all the possible variables, then one can find out. im too lazy to

[This message has been edited by FieroWannaBe (edited 07-30-2005).]

quote Originally posted by FieroWannaBe: i dont understand the specific logic behind, "speeds are limited" the short strokes of a engine with high RPMs will make them spin much much FASTER in reality. At high rpms, the pistons are moving up and down very, very fast, but they arent going much more DISTANCE than an engine with low RPM's and a long stroke, even when the piston is moving much SLOWER.

On an engine with a 4" stroke, each revolution of the motor moves a piston 8 inches. At 4,000 RPM that piston is moving 4,000 x 8" x 60 minutes/hour = 1.92 million inches per hour, or 363 mph. Now, the speed isn't linear, the piston moves slowest at top and bottom and moves fastest at exactly half stroke, I don't remember how to calculate the instantaneous speed at half stroke, but for purposes of comparision we can probably ignore that. Now, take a 3" stroke motor, 4,000 x 6" x 60 minutes/hour = 1.44 million inches per hour, or 273 mph. That's a nearly 25% reduction in speed, so a shorter stroke motor can spin higher RPMs (all else being equal) before running into problems with velocity-induced oil film failure on the rings and ring flutter.

What import does this have on a race motor? Horsepower is basically (torque*RPM) divided by 5252. From a more practical standpoint, each cylinder gives a push on the crank every other engine revolution, so to get more pushes in a given length of time you need to spin the engine faster. To spin the engine faster you need a shorter stroke to reduce piston speeds, and a shorter stroke also reduces rod bearing sideloads. Now, shorter stroke reduces torque, but power is made up for by having more strokes such that the accumulated total is increased.

For example, I've seen quoted figures of 96mm bore and 41.4mm stroke on the Cosworth CR-1 F1 engine of a few years back, that's a ratio of 2.32:1 compared with the stock Fiero 2.8 numbers of 89x74mm, 1.20:1 ratio or the Iron Duke 2.5 numbers of 4" bore, 3" stroke, 1.33:1 ratio.

JazzMan

quote Originally posted by JohnnyK: Well for one thing I'm not going to go out of my way to build a car for the sole purpose of pulling a load up a hill.. Obviuosly trucks are meant to do that..

I didn't mean anyone in particuler. Just seems there are so many of these "400" or more horse power, four cylinders around, surely someone can talk their buddy into putting a trailer hitch on one and giving it a try. Make a video while they are at it too, please.

quote Originally posted by crzyone: HP is work. The more hp you have, the more work your engine is capable of doing. A 400hp 4 cylinder is more powerful than a 350hp hemi period.

This being said, I just want to see it, that's all.....

Kevin

quote Originally posted by JohnnyK: Why would anybody say a 350HP v8 woudl beat a 400hp 4cylinder? I mean, obviously (And I've seen it done a million times) you can't take the gearing and the setup for the curve of the other engine and expect it to be faster in the other engine, but once you get a drivetrain setup that takes advantage of the specific motor, it will win.. Cylinders are pretty inconsequential for point of a race.. Torque does not 'win races'.. Was this said in a 60's commercial or something? I don't care if you have 1000 ft/lb if it runs out of breath in a second.. Sorry if that has been previously said in the thread.

You're a Johnny come lately to the discussion Pun but no harm intended. So maybe you missed the fact that this whole discussion is based on a very specific scenario which involved pulling a large heavy load up a steep hill. So granted a 4cly can be built to do that, but how would that gearing affect how it behaves in other areas? My point as before, while it can be done it's just not as practical as the hemi doing the same thing.

quote Originally posted by Unrivaled: You're a Johnny come lately to the discussion Pun but no harm intended. So maybe you missed the fact that this whole discussion is based on a very specific scenario which involved pulling a large heavy load up a steep hill. So granted a 4cly can be built to do that, but how would that gearing affect how it behaves in other areas? My point as before, while it can be done it's just not as practical as the hemi doing the same thing.

The exact same way that the gearing has on a truck meant to pull a trailer.. A massive pickup with low end torque is great for pulling a trailer up a mountain, but it's not going to do much at the track.. I dunno, my basic contribution to argument was 400hp is 400hp.. Doesn't matter if your making it with 2 cylinders, 4 cylinders, 8 cylinders, or a giant pulling your car down the track..

Lets look at the situation a diferent way:

In The Dodge Ram, you could get a 5.9L Cummins Diesel it makes 500 lb/ft torque, and 300HP since it is a diesel it is low reving. Then you get the Hemi, 345HP and 375 lb/ft torque it is higher in HP, and lower in torque, and higher reving. Then you get the L4 with 400HP and 200 lb/ft torque, and is the highest reving.

I know people with both the CTD Ram and a 5.7L Ram, and people say the Hemi doesnt tow very good, the CTD tows like there is nothing behind it. The CTD has more torque, but less HP, on a flat road going a constant speed, both the 5.7L and CTD pull the same, but when you have to accelerate or climb hills, the CTD easily walks away, and it has 2 less cylinders.

The Hemi has a higher torque and HP peak than the engine it replaced the 360. I also know people who have had an earlier Ram with that engine, then went to a Hemi, and they all said the 360 pulled better because of its lower torque curve, the 360 only had 245HP.

Anything can to something the same speed on level ground, but it is the torque that is needed to get the mass moving.

Semi's only have 500HP or so, but over 1000 lb/ft of torque.

If the L4 got 400 lb/ft of torque it would pull great, if you could keep the engine reving right where it gets that torque, but with the smaller displacement, it would be higher in the RPM's. Not many people would rev a vehicle to 6000+RPM to accelerate from a stop.

I heard somewhere that below 30MPH you use mostly torque, above 30 MPH is it mostly HP.

[This message has been edited by befarrer (edited 07-30-2005).]

quote Originally posted by befarrer: I heard somewhere that below 30MPH you use mostly torque, above 30 MPH is it mostly HP.

Statements like that really irk me..

quote Originally posted by JohnnyK: The exact same way that the gearing has on a truck meant to pull a trailer.. A massive pickup with low end torque is great for pulling a trailer up a mountain, but it's not going to do much at the track.. I dunno, my basic contribution to argument was 400hp is 400hp.. Doesn't matter if your making it with 2 cylinders, 4 cylinders, 8 cylinders, or a giant pulling your car down the track..

Johnny that's fine and dandy if you're talking about a track that is a flat level surface. But we aren't so maybe that is where the confusion comes in.

This is Bonzo Sr. The driver of the Ram.
I don?t know how to quote some of you guys but I'll do it this way.

Bfarrer,
To say the Hemi doesn't tow very good and to never have done it. You don't know what you are talking about. This isn't my first truck. This thing will tow my load like there's nothing back there. Pull a 3+ ton load up a 4% grade and accelerate the entire time. I?m not saying the little 4 banger can't do it I'm just defending my truck.

JohnnyK,
This thing will get up and fly when asked to. It may not smoke a sports car but it can do an 1/8 mile in about 9 secs and ¼ mile in 14 secs.

The bridge I was pulling this load up was 2 miles long and 175 feet high. That?s about a 4% grade. I didn't floor the truck because some of the cargo was loved ones. I'm not sure what it would have done if I gave it all it had.

Bonzo Sr.

[This message has been edited by bonzo (edited 07-30-2005).]

quote Originally posted by FieroWannaBe: There is no HP vs TQ; they are both simply dirivatives of each other. It's more af analysis of how they are placed in relation to each other on the TORQUE CURVE.

To be specific, HP is a dirivative of torque. Torque is a force and can be measured. HP can only be calculated.

So, back to the original question.

Yes, a 400hp 4cyl engine will pull a load faster than a 350hp V-8.

Look at an SRT-4. It makes 230hp/250lb/ft with 2.4L. A turbo 4 cylinder that makes more torque than hp. It has a fairly long stroke for a 4cyl, and as a result also has a low redline of 6000rpm. Guys that upgrade these engines will make 400hp with 450lb/ft.

Honda uses "oversquare" engines that have a shorter stroke, thus increasing its rpm potential but cutting its peak torque.

To lump all 4cyl engines into the category of having no torque is false. With the SRT-4 engine, you wouldn't even need to get custom gear ratios, it has plenty of torque to get a load moving with the same gear ratios as the truck.

quote Originally posted by bonzo: JohnnyK, This thing will get up and fly when asked to. It may not smoke a sports car but it can do an 1/8 mile in about 9 secs and ¼ mile in 14 secs. The bridge I was pulling this load up was 2 miles long and 175 feet high. That?s about a 4% grade. I didn't floor the truck because some of the cargo was loved ones. I'm not sure what it would have done if I gave it all it had. Bonzo Sr.

Perhaps, but a 4cylinder with more hp/torque will tow it better, provided you keep it, the key thing, in the rpm range! Be it through stall converter, shifting, gear ratio, etc.

ive alos lined up, with a 01 cavalier, not the z24 the other thing. it has a cold air intake and exhaust, my fiero is all stock, im kickin his ass until about 60 and then he starts to pull away from me very slowly...he got bumper to bumper......althoyugh the fiero should have more horse power....140 for me and 120 for him, give or take a lil

I have driven a 2004 SRT-4 which the engine is rated at 230hp/250 torque
I had a 3.4L carb'd engine in my Fiero with 223hp/249torque (engine dyno rating)

I prefer the 3.4L carb over the turbo'd 4.

The 2004 SRT-4 (with a manual trans) "as tested" does 14.2 seconds @97mph (not me driving it, but what magazines have tested a stock car at.)
My Fiero with the 3.4L and an auto trans did 14.26@94mph (Great Lakes Dragway, Me driving.)

So Dodge used a "high-tech" 4-cyl and added a tuned turbocharger set-up and basically made the same power as a 20 year old technology pushrod engine with higher displacement and a carb. Both cars went about the same in the 1/4 mile.

A normally aspirated 3400 is 185hp, add a properly sized turbo and use the same boost levels as the SRT-4, and you'll have more power then the SRT-4.

Does more displacement mean more power? My answer would be "yes".

The point everyone is falling to see here is tow ratings. That 400 HP import will be rated at a much lower towing capacity than the 400 HP truck. Towing capacity is based on vehicle weight and has more to do with braking capacity of the vehicle, that is why the smaller import will not be able to tow a bigger load like the truck could, even though it has the same HP. It wouldn't be able to stop, even if it had good enough brakes, if the load is too big for it. It doesn't have the same mass the bigger vehicle has to handle a bigger load safely. If you don't believe me do a google search on how towing capacty is determined.
Anybody see the video of the small car towing a trailer home up a hill? Remember what happened when it stopped going up the hill? The load was so big that it dragged the small car backwards, down the hill out of control, with the brakes locked up.
The smaller high HP import would be able to tow the same weigh but it wouldn't be safe if it is beyond the vehicles towing capacity.
To put it in perspective a curve weight of 6076 pounds Dodge Ram truck 2500, when properly equipped it can tow over 13000 pounds with a 5.9 liter diesel engine that has a 325 HP rating and 610 of pound-feet of torque. Let's compare it to a curve weight of 3298 pounds Subaru STI with 2.5 liter engine that has 300 HP and 300 pound-feet of torque. This vehicle is rated to tow 2000 pounds. The truck can tow almost 7 times as much as the car and yet the are within 25 horsepower of each other. So tell me which one can do more work?

[This message has been edited by avengador1 (edited 07-30-2005).]

When dealing with cylinder quantities, remember that the more cylinders you have, the more power pulses you have per engine revolution, that increases torque across the board. The more cylinders for a given displacement, the flatter and broader the torque curve.

JazzMan

quote Originally posted by JazzMan: When dealing with cylinder quantities, remember that the more cylinders you have, the more power pulses you have per engine revolution, that increases torque across the board. The more cylinders for a given displacement, the flatter and broader the torque curve. JazzMan

Good point!!

quote Originally posted by Oreif: I have driven a 2004 SRT-4 which the engine is rated at 230hp/250 torque I had a 3.4L carb'd engine in my Fiero with 223hp/249torque (engine dyno rating) I prefer the 3.4L carb over the turbo'd 4. The 2004 SRT-4 (with a manual trans) "as tested" does 14.2 seconds @97mph (not me driving it, but what magazines have tested a stock car at.) My Fiero with the 3.4L and an auto trans did 14.26@94mph (Great Lakes Dragway, Me driving.) So Dodge used a "high-tech" 4-cyl and added a tuned turbocharger set-up and basically made the same power as a 20 year old technology pushrod engine with higher displacement and a carb. Both cars went about the same in the 1/4 mile. A normally aspirated 3400 is 185hp, add a properly sized turbo and use the same boost levels as the SRT-4, and you'll have more power then the SRT-4. Does more displacement mean more power? My answer would be "yes".

Orief you have to get with the new millennium, you know 4 bangers are untouchable.

Going Carb and a pushrod engine!!!!!!!!!!!!

holy sh!t you're a Caveman

quote Originally posted by JazzMan: When dealing with cylinder quantities, remember that the more cylinders you have, the more power pulses you have per engine revolution, that increases torque across the board. The more cylinders for a given displacement, the flatter and broader the torque curve. JazzMan

I will 2nd the good point and add

Anything you can do to a small displacment motor to make power

Can be done

To a larger displacment motor to make more power

You guys keep going around the original question.

Avengador, towing capacities are largly based on brakes. Trucks have hd brakes.

quote Originally posted by crzyone: towing capacities are largly based on brakes. Trucks have hd brakes.

If towing capacity is based largly on brakes, Then why does a 1987 GMC Jimmy with a N/A 4.3L have a towing capacity of 3500lbs and a 1987 GMC Typhoon with a 4.3L turbo, larger rotors with dual piston calipers only have a rating of only 500lbs?
It is obvious the Typhoon has more HP and torque and the engines are the same displacement, vehicle size, and weight, so why the towing capacity difference?

(Actually I know the answer, lets just see who else does.)

[This message has been edited by Oreif (edited 07-30-2005).]

Suspension too... Thats why when you see an F-150 chugging down the road with a load 3000lbs too much for it, the front of the truck is pointing skyward.

quote Originally posted by JazzMan: When dealing with cylinder quantities, remember that the more cylinders you have, the more power pulses you have per engine revolution, that increases torque across the board. The more cylinders for a given displacement, the flatter and broader the torque curve. JazzMan

I was just about to say that...beat me to it

quote Originally posted by Oreif: If towing capacity is based largly on brakes, Then why does a 1987 GMC Jimmy with a N/A 4.3L have a towing capacity of 3500lbs and a 1987 GMC Typhoon with a 4.3L turbo, larger rotors with dual piston calipers only have a rating of only 500lbs? It is obvious the Typhoon has more HP and torque and the engines are the same displacement, vehicle size, and weight, so why the towing capacity difference? (Actually I know the answer, lets just see who else does.)

I am guessing it has something to do with the tranfercase in the Typhoon, Being full time all wheel drive.

------------------
85GT 5spd MSD Everything,4.9 With Nitrous. www.captfiero.com

quote Originally posted by avengador1: Anybody see the video of the small car towing a trailer home up a hill?

I love that video

We now return you to the discussion already in progress...

Lotta posts here, dont have time to read them all

bottom line:

Rice is bad mmmmkkkaaayy...

quote Originally posted by 86GT3.4DOHC: Lotta posts here, dont have time to read them all bottom line: Rice is bad mmmmkkkaaayy...

I guess you werent here when all the RICERS came outta the closet.
This is the new RICE hangout.
Pay attention

quote Originally posted by Oreif: If towing capacity is based largly on brakes, Then why does a 1987 GMC Jimmy with a N/A 4.3L have a towing capacity of 3500lbs and a 1987 GMC Typhoon with a 4.3L turbo, larger rotors with dual piston calipers only have a rating of only 500lbs? It is obvious the Typhoon has more HP and torque and the engines are the same displacement, vehicle size, and weight, so why the towing capacity difference?

Typhoon has sportscar springs, not towing springs.
Go ahead and put a 5th wheel in a Syclone...

Rice? So, anything less than 8 cylinders and more than 16 valves is rice? Ghey.