Ok, he is making 500hp at what rpm??? Horsepower doesn't move you, torque does. What good is all of that power at 7000rpm when you are trying to move 10,000lbs of truck and trailer? None. Torque is what you want for pulling power. This is why the PowerStroke pulls so good. It has 565ft/lb of torque. The horsepower numbers are lower because it is useless for towing. Horsepower is a realitive term for how fast a motor will rev, not how hard it will pull.
Jimmy

 

yes a streetable 351 is what I was getting at. This car is driven multiple times a week.

I stand corrected the car made 500.1hp and 432rwftlb's of torque. He had well over 390 rwftlbs of torque at 2500rpm. That is a crapload of torque. How much rw torque does a new 6.0 powerstroke have? If it had 565 crank with a 20% driveline loss that is 452 rwtq or so. This 5.4 is only a couple ftlb's off of that mark.


BUT I am not saying this engine would pull like a diesel, that was not its purpose. The purpose of my post was to reinerate that these modular engines can produce a massive amount of power and maintain decent fuel economy.

BTW.
He revs the car to 7250rpm's.

 

I'm with you tow. I dislike the modulars strongly. 393 being planned.

 

With all the talk about push rod engines, why don't we just go back to am radio and 78's. I have been a big fan of the modular design from the beginning. OHC are the way to go. Why do you want to run a single cam through push rods then to rocker arms and finally opening the valves. I have had the 351 C/W, the 300 six and the BB460 along with my 5.4 and I would take the modular any day.

TECHNOLOGY RULES!!!

BTW, the Hemi thing that dodge has is a big marketing ploy. Most new engines today have hemi heads or something close to it. They used to be something back in the day but everyone has caught up and dodge thinks it can market it again. The rednecks might fall for it.

Mark
99 Expy XLT

 

Technology rules if it is applied right. Why run pushrods? Because they work. Do you really gain much with ohc's other than making a wider engine? Why does the new 3 valve and 4 valve make 40 hp and 10-20 tq over the 2 valve? Wouldn't you expect more out of such a significant increase in airflow? I have many more ?'s that lack good answers concerning the Triton's.

 

Remember where the modular V8 came from... it was originally designed for a front-wheel-drive chassis, making motor length crutial. So, they used narrow main bearings. I think only the Lincoln Continental came out with the 4.6 in it. Then, they decided, hey, the 302 is old, let's use the 4.6 in the rear-wheel-drive vehicles too! Like Crown Vic's. Then, the t-bird/Cougar in '94, then the Mustang in '96, Mustang Cobra, trucks, etc.

Turned out the 4.6L just didn't have the guts for trucks (or SUV's) and those thin main bearings. Out comes the 5.4L with a higher deck and more stroke. Then, the V10 is built using the 5.4L geometry.

Overall, Ford took a "stepped in it" kind of approach with the modular motors. I don't think they ever intended to use it in everything, but trying to save money and time, they used the OHC design because it was what they had at the time.

Me, I'm proud to have had two 4.6L's in a '96 t-bird/'97 Cougar, and my V10 is the best truck GAS motor I have seen for torque. OHC is not just for high RPM, it's for the less restricted heads that are made possible because you don't need to angle the intake ports around the pushrods. Pushing around all those pushrods also takes a toll in friction and wasted power. The OHC design moves force from the cam to the valve much more efficiently. Look at the width of the cam lobe in a pushrod motor and compare to the width of Ford modular cam lobe. The Ford lobe doesn't have to be that wide because it doesn't have to take the extra load you have with pushrods. Valve springs are heavier for pushrods because not only do they have to close the valve, they have to push the pushrods back too.

Aluminum heads are not a bad thing.

An '02 V10 puts out 350ft/lbs of torque at 1000RPM according to a Ford torque curve in the brochure. It only puts out 425 PEAK. That flat torque curve is helped by well-breathing heads that can move a lot of air at LOW rpms. My FE390 can't do that, and I spent a lot of time and effort trying to bring up the low-end torque. It's scary for a 292/292,.554"/.554" cam to put out what my FE390 does, but the V10 just plain beats the pants off of it.

ak

 

The Dodge is the first Hemi V8 pushrod motor in years. It has 17 mor cubic inches and 85 more HP. Not bad for an old pushrod motor. I saw a 1500 Hemi truck yesterday and that thing ran like a striped ape!!
I don't have a problem with the overhead cams, I just think that they could have done better in the power dept. Heck it took them 7 years to correct the sparkplug popping out of the head issue, then 6 months later, they bring out the 3 valve motor with an "all new spark plug design".
Oh, and my old 77 460 with a 3.00 gear and 32" tires will outpull my 5.4L anyday!!
Jimmy

 

No replacement for displacement?

Pushrods and OHCs are both good engine designs if done correctly. The tale about my Mustangs are proof that any pushrod engine (in my hands, at least) can be a real dog. As another example, just think about when all the smog restrictions came out in the mid 70's and a new stock V-8 had horsepower numbers like todays OHC big 4's and V-6's, but still had crappy gas mileage.... it's all in how they're engineered. What about the 255 V-8? What was up with that? You learn as you go, sometimes it requires a step back.

The DOdGe Hemi? It's a marketing ploy...Diamler Chrysler owns the Hemi name as a trademark. Yes, all the manufacturers use a hemispherical head design in most of their engines today. More cubes should mean more power. If they came up with 100+ more horses and 75+ more pound ft of torque over the new 5.4's numbers, then I'd drop my jaw. Good numbers, but I'm not that impressed.

-Kerry

 

I guess my point is after driving 5.0 & 5.7L pushrod engines for years would the buyer of a new truck with a 4.6 or 5.4 notice a big improvment in torque or horsepower?

I have built a few performance engines and I understand the theoretical efficency of OHC designs I also know that at the RPM truck engines operate in (max 6000) the advantage over a well designed pushrod setup with roller cam and rockers is negligable, certainly not enough for the driver to notice.

Simply put when the salesman (or engineer) starts talking about all of the advantages of the modular I say ok so you must have outstanding torque and horsepower numbers to show me compared to other V8s this size right? No. Ok then this thing must get 25MPG right? No.

Ford had a pushrod "Hemi" engine it was the 1969-1970 Boss 429! That Boss was a great race engine but it had no low RPM torque, a regular wedge head 429 CJ was a much better street engine.

Overhead cam V8s aren't the latest modern high tech idea remember the SOHC 427 from the mid 1960's?

 

It's getting VERY tedious to hear all you people talking about peak HP numbers.

Get it through your collective heads (no pun intended!) The peak HP number is hardly a number you should put any value in. Likewise, peak torque.

A higher-RPM with the same torque will yield a higher HP number ( torque*RPM/5252=HP ). Likewise, peak torque can be tweaked upward until the motor's useless for street driving.

Spin a motor at a higher RPM with the same torque and you magically increase HP. Why do Honda 4-bangers put out so much HP? Because they produce a reasonable amount of torque but at a VERY high RPM. Down low, they hardly do anything even with variable valve timing.

Torque is that seat-of-the-pants feeling of acceleration.

YOU MUST COMPARE TORQUE CURVES. Sports cars, trucks, land-yachts, motorcycles, it doesn't matter. You have to look at the ENTIRE torque curve. What's the point of getting 500ft/lbs peak torque when near idle it's 50?

A motor with a near-flat torque curve may only put out 425ft/lbs at say, 3000RPM (think V10). A motor with a rounded curve will put out 600ft/lbs at 4000RPM and have a higher peak HP. BUT - which is faster on the street? probably the one with the flat torque curve, because in the ENTIRE rpm range, there is GOBS of torque, while the other one is still trying to get moving.

The torque curve on the V10 is very flat. 350ft/lbs of torque at 1000RPM! That's basically 82% of peak torque at near IDLE. I'd love to see a Dodge Hemi torque curve, it probably doesn't make more than 200ft/lbs at 1000RPM.

Likewise, comparing my old FE390 to my V10, the FE makes nothing even CLOSE to 350Ft/lbs at 1000RPM, but it certainly has way more HP than the V10. Which is the better truck motor, or for that matter, plain street motor? The V10, even in a heavier vehicle (1000lbs more).

The 2-valve 4.6L has a pretty good torque curve. Not a high peak, but overall a nice decent motor. For 281 cubes, it's actually a decent car motor. Nice, wide torque curve.

Come to think of it, comparing my FE390 to the V10, one is 390 +.030" over, the other is 415 cubes. Pretty close. The 390 is worked witha big cam, high compression (10.5:1), cam degreed for low-end grunt, almost no porting on intake, plenty on exhaust. I was trying for low-end grunt. Got it too, it puts out much more than the stock 390 or 360 at 1000 RPM. BUT - it's NOTHING compared to the V10. With the V10, I can roast the tires up through 2nd gear STOCK. Much less HP then the 390, but it outperforms it in every way except at 5000RPM

ak

 

Yes, the V-10 has a great torque curve, but we are talking 5.4L's here and mine doesn't really start pulling hard until about 2500rpm, by then, I'm over 20mph. I was hoping for more get it rolling grunt. The new 3V 5.4L is supposed to have most of it's torque at 1000 rpm too, due to the redesigned head and variable cam timing. My 2001 does not!! I would have thought that 3.55 gears and the wide ratio tranny would help in the grunt dept.
If I ever get another one, it will have 4.10's front and rear. I can't afford to change the ones that I have now so I'll just wait until mine is payed down more, give Ford time to work the bugs out of the 2004-up models and I'll trade her in on one of those.
Jimmy

 

I know very well what a torque curve is and comparing a fuel injected 10 cylinder engine to a carbureted 8 cylinder is apples to oranges even if the displacment is nearly the same. On a multi port fuel injected engine the intake manifold plenum and runner length can be optimized for torque because the intake flows air only not air & fuel. Also the EFI's fuel managment system is constantly adjusting A/F ratio, timing etc for optimum power regardless of temperature, altitude or other variables.

The broad, flat torque curve of modular truck engines comes from several factors, stroke, port & valve sizes, intake manifold runner length ECM programing etc...but not from mounting the camshafts overhead.

My point is mounting the cams over the heads provides no performance (torque) increase for the RPM range these engines operate in. It adds complexity and makes repair in the field much more time consuming (expensive) and difficult but returns no noticable advantage.


I know the theoretical advantage behind the high tech overhead cam design, problem is I don't notice any real advantage behind the wheel!


If the 5.4L modular were designed with iron heads a single cam in block, pushrods, roller lifters & rockers moving the valves the same spec the torque and HP would be identical. But the engine would be more durable, cost less to build and repair and externally much smaller.

Speaking of pointless overcomplication someone explain the advantage of an electrical motor opening and closing the throttle(2004 5.4L 3-valve Triton) instead of a simple cable attached to the accelerator pedal.

 

Isn't technology grand?

The automakers are trying to make all vehicles "drive-by-wire." There are many of us who'd prefer to work on the vehicles then have to give out our hard earned dollars at an ungodly hourly rate. It is the auto manufacturers, as well as the environmental government agencies and any of those who sit behind a cover and claim to love the environment while lining their pockets with your money, that are making the past time of home repair fade away. It may be adding to the economy and saving the environment, but it's emptying our pockets to do so.

I see you point, towboat, it finally took the last line in your statement to wake me up.

The ease of maintenance, not how much horsepower or torque in any range, is the reason they should bring back the simplicity of the design of a good old iron block pushrod V-8.

For now, though, I'll have to live with society and drive my ecologically consciencious, modular powered, ...... gas guzzling (teehee ) 2000 Ford truck.

-Kerry

 

If anyone can't get good amounts of torque out of 4 plus inches of stroke, they should quit while they are behind. If OHC's are so much better than pushrods, wouldn't everyone use them by now? Want something to beat up on a v-10. A 393 Ford Motorsport crate engine with a little tweaking (truck oriented cam) should do the trick. And it won't have piston slap and spark plugs that go on vacation.

 

Gee we have opened up a big ole can of worms here!!!
Jimmy