I think you got that last sentence backwards
05 M6 YJ GTO 1 of 447
Jeremy Knox wrote:
The Cadillac XLR with 4.4 Northstar S/C
12PSI of boost and 443hp with a bore of 3.7 inches and stoke of 3.3 inches
The Ford Mustang Cobra with 5.4 SOHC S/C
13.5PSI of boost and 500hp with a bore of 3.552 inches and stroke of 4.165 inches
They're fairly similar and the Northstar has the advantage of making a lot more power for it's size, but look at that gigantinormous stroke advantage that the Mustang has. Lots of revving there. The Northstar's gonna make all it's power down low, Mustang's gonna keep going. Truth be told, I like em both. The "advantage" really comes down to whatever bias you may have.
you say the north star w/ less stroke will make its power down low whichi it should be making more up top. the stang should be making more power down low due to its stroke size
05 M6 YJ GTO 1 of 447
you also have the valvetrain mixed up - the 5.4 is dohc/4v, same as the northstar.
"i promise we won't get drunk, and go out in boat in the dark, stand up in the boat and fire the gun into the air unless we have life jackets on."
@!#$, you're right. I did get it backwards. In any case though, the overall point still stands. The design is what factors in the most in how good an engine can be, not just horsepower and size.
I know what you're saying, and I agree 117% - engine design enfluences many characteristics besides horsepower. Most people are too stupid to realize, but power output, or horsepower per litre(God damn that pises me off!) aren't the be all and end all; there are also power to weight ratio, powerband, useable rev range, how quiclky it builds revs, etc.....
"i promise we won't get drunk, and go out in boat in the dark, stand up in the boat and fire the gun into the air unless we have life jackets on."
^^^
probably why LSxs own all
05 M6 YJ GTO 1 of 447
^^^And that's exactly why I despised the LT1, yet the LSx gives me major wood
"i promise we won't get drunk, and go out in boat in the dark, stand up in the boat and fire the gun into the air unless we have life jackets on."
Hello all, new to this board but I have a few things I can add to this topic.
To many contributing factors, on top of what Jeremy has already added you have such things as rod lenghts, bearing journal diameters, material weights, material weaknesses, port velocities, angles and locations of injectors, etc,etc goes on forever. its all about what will the majority of people that buy this vehicle with this engine will be doing with it? and what will the minority be doing with it? this is where a well rounded engines roots started and builds from there, it may not be the best at any one thing but will compete on an average across the board. I think Both these manufactures have done an outstanding job with both these motors at this point.
I think for the most part i agree with where Jeremy is going with this topic.
The answer to this topic is simple, the general public is a hard crowd to please everyone has their on ideas on what they like and dont like and not all agree so the answer is their is no clear winner. Manufactures have their hands full alone just trying to please and target the majority for that fact sometimes its just plain more profitable to target the minority but just as challenging to please that crowd. If their was a clear winner here we would all be driving the same vehicle with the same engine.
Now my interest in this topic is the art of where the manufactures are taking technology all the different focuses and not forgetting their roots in things and areas left open and unsolved in the past that technology can answer now, mixing some of the lessons learned of the past with todays technology and yester years fundamentals.
For example this is kind of how I look at things at this point.
LSX: I look at this motor as a hard lesson learned at fords expense, why? Because GM watched and learned Fords phase with the 351c 4v, when Ford gave up GM designed and engine with the clevelands strong points and none of its flaws. Ford had great hp potential with those heads nearly perfected by nascar, however thats all they had, the general public didnt like the motor mostly due to low port velocities at low rpms and the bottom end of the engine had serious oiling problems resulting in spun bearings at the rpms the heads where designed for.
Like ford the block these heads would go on would be different from anything else they where running at the time a new gen block in the sb world and would branch out to serve other purposes. I know people will argue the failure of the clevelands and claim they had no such problems if oil restricts where set up properly and external oil passages where in place on the blocks etc, Bottom line put the heads on a windsor to make a clevor fix the port velocities on the intakes buy the kit to raise exhaust ports .75 in. and you end up with.....an expensive version of an LSx motor, yes different by manufacture but comparable in performance but and leaks everywhere.
ford mods: Check out what ford learned in the late 60s with the 427 sohc and you will find many similarities to their newest modulars ford made great numbers with this tech at the time but was short lived due to the end of the bb wars hampered by coming up emission standards. now as technology has allowed the manufactures to get back in the hp game and pass emission standards at the same time manufactures are looking back at some of their hp ideas from the past, anyone remember the tunnel port 289s? Ford had great success with the 289s but because of ci displacement the engine was only going to make x amount of torque and hp in the lower rpms so ford started looking into to top end of the rpm range to make the big numbers they where looking for and this brought the tunnel port heads OUCH!!! no low rpm port velocities and required 9000+ rpms on a 289 to make hp gains to utilizing these heads. did not work, had to up the displacement and refine the heads so next came the boss 302 which was a little better but still not what they needed, up the cubes again now you have the 351c with the exact same heads a the boss 302 with different coolant passages for the new block, well ==more problems.
well technology has ansewered the problems for all the above for ford now lets take the successful design of the 427 that they never got to utilize mixed with the high winding small displacement idea of the 289 and address the low rpm small displacement port velocities now and you have a modular motor. success it worked now lets start building on this platform and you have the dohc 32v, sohc 24v, and the 5.4 work horse versions.
Both manufactures found success for periods of time throughout the 70 and 80s with what i look at as their carry overs for the time with their base line blocks standard sbc and fords winsor both surrendering to the lower to mid rpm engines that found their own success stories at the time but the hold back of top end power or bottom power but not both is gone today and manufactures are looking back as much as looking forward in the evolving topend wars now and both have their own and very different ideas for today I find it very fascinating on where they are both headed.
I smell an end to monster 4.0" stroked smallblocks as manufactures are finding more and more usable and reliable topend power with shorter stroked engines.
I also believe the direction ford is going opposed to what most are thinking or wanting is once they find the power they a looking for in the 4.6 rather then upping the cubes they will drop them again and try to achieve the same power levels through even smaller cubes.
Another though of mine on fords 4.6 is i liked the split port design "b" style like chevy used in the lt5 but ford killed it by only running 8 injectors rather than 16 the secondary intake port had no way to keep build up down and the more miles you put on it the more it would build up and the less hp you had. I think they killed it because of the price of 8 more injectors per engine vs just going to one big port, and the advantage to the split port with 4 valve per cylinder and block off plates is the fact you can run to different intake lifts and durations primary valve low-mid lift and duration and secondary mid to high rpm lifts and durations resulting in good bottom end great mid range and fair topend. Currently with the "Tumble port" 4v heads i dont think they a achieving anything a 2v engine cant do besides lighter valves less spring pressures needed to return them at high rpms.
