School us on engines...

Discussion in 'SN95 4.6L Mustang Tech' started by GDawg, Dec 23, 2006.

  1. I have to say, there's a local shop here that has apparently gotten some very nice numbers out of ported LS series heads by partial-filling the ports and machining them out again at a different profile and volume. The result is flow rates less than what most people consider "good," yet the velocity increases over stock seem to make more power than heads with massive ports and high flow rates. In short, he backs up what Bill Fisher is talking about with respect to velocity meaning more than port volume when the rubber hits the road.

    I'm not the expert, and even if I knew exact numbers, I wouldn't be at liberty to give them (I hope I haven't said more than was kosher already), but I've seen the dynos, been to the shop, heard it from the mouth of the man doing the work, and am familiar with his references and seen and heard his homework. So anyone who thinks porting heads starts and stops at bigger ports and high numbers on the flow bench has earned my skepticism.

    However, there is more than one way to make power, and who am I to say one way works and another doesn't? I'm just saying Bill Fisher's ideas aren't the ravings of an ignorant. He's not the only one who has seen what is counter-intuitive. He's just one of the generous ones who'll share his knowledge given half a chance. It's a shame people who should be taking notes and asking pointed questions are busy arguing instead of trying to improve their work.
  2. BTW, speaking of Cup motors, anybody wanna see a nice shot of a Hendrick Motorsport's Cup motor that a buddy of mine from HM emailed me? :nice:

    I made this one smaller, but I also have the original hi-res shot if anyone wants it.

    View attachment 412999
  3. Nobody in this thread (to the best of my memory) ever said go with big ports or go home, that’s just a side effect of the way billfisher “persuades” his audience. You cannot minimize making power to it's all about flow, or it's all about velocity, or it’s all about port volume. Port volume, port shape, valve size, flow, and velocity are but individual parts of a MUCH bigger story. Bottom line is that more velocity does not equate to more power. If it was all about velocity, sonic choke would be reached way to soon especially on a N/A motor. With these 4.6 2V heads you can’t get much over .57 MACH without seriously hurting performance…on an LS1 head you can get about .6 MACH before performance starts to suffer. You don’t ever get anywhere near “supersonic speeds” like bill referred to. That is just another post that shows his lack of a true working knowledge. But that's just my opinion and everyone else is welcome to form their own. It’s a well balanced combination of all of those aforementioned “parts” of the story plus all of the additional work that goes into making an efficient head. Speaking of efficient, that is usually the tell tale sign of well a cylinder head will perform. BSFC (brake specific fuel consumption) has been and still is a solid way of determining how efficient and thus how well a cylinder head will perform. Just 10 years ago (and I am only 33) I remember guys bragging about getting around a .45 BSFC, now if you aren’t below .34-.35 in the you aren’t competitive.

    If you would like to get some good reading on this subject, I’d recommend spending some time in the Advanced Tech section of And ask those guys what they think of this velocity hype. If you call a performance speed shop and they tell you that their set of heads makes more power because they have higher velocity ports, hang up the phone.
  4. Very IGNORANT statement.

    There are Very fast Fords.. and Very Fast Chevys.

    Motors make power in the heads... Nitrous cars can run very fast with stock or lightly ported heads. My LS1 Firebird (N20) made much power, but when I flowed the heads- they were not much better than stock.

    Ford has the edge in NA power with decent flowing 4V heads, despite smaller displacement. However- the LS2 and Z06 Vettes also kick ass- 10's with light mods, driven to the track.

    Before you diss the LSx motor, here's some "local" numbers from a LSx board:

    1) Bowerboy- [email protected] ---------- C5 .......402CI ..........STS

    2) ****nityZ28- [email protected] -----------Z28 ......408 ..............??

    3) Noyzee- [email protected] ----------------- Z28.......402CI...........N2O

    4) Frans96ss- [email protected] ------------99Z28......408ci....350shot

    5) Stealth turbo C5- [email protected] -- 99FRC....388ci....STS turbo

    6) [email protected]/a-----408-----n2o

    7) Burbanman- [email protected] ------------02.......347ci.....NXDP

    8) ATVracr- [email protected] -------------99formy.....370ci........N2o

    9) Nautilus- [email protected] -------------00SS.........383............N20

    10) Tom the Roofer- [email protected] -----SS ...........421ci............n/a

    11) 35TH 427 SS's dad- [email protected] -------C5...........427............TT

    12) smokeum99ta- [email protected] --------99Ta .......?? ............??

    13) 35TH 427 SS- [email protected] --------- 02z28......LS7........N/A

    14) choppin-suey- [email protected]

    15) n2ostroker- [email protected] -------- 00T/A.....402.......N2o

    16) Red Dragoness- [email protected] -----02T/A..... 348ci....N2O

    17) DEEZ98Z- [email protected] -------- 98Z28 .... ARE347..N2o

    18) GM Muscle- [email protected] ----------- 00Z28.....SI........N2o

    19) Camaro1053- [email protected] --------- 98T/A .....383........ N2o

    20) Bspz28- [email protected] -------------- 98Z28.....H/C.......N/A

    21) Brent C5- [email protected] ------------ 97C5.......APE346...S/C

    22) B-man- [email protected] ---------- 01T/A.....eastside346.....N2o

    23) Fireball- 10.48@129.8------------- 99 T/A....H/C........N/A

    24) Purevl [email protected] ---------------- z28. .......408.......FI

    25) WS6transam01- [email protected] --- 01Ws6.....H/C.......N/A
  5. what we have here is failure to communicate.....

    i am fully competent. i am 41. no younger. so i am older than whatever you are called.

    i have a different philosphy, and it should be obvious from the combo i am running now. i believe torque wins. toque from the same cubes or less.

    my motor makes 325+rwtq @ 3000 340 @ 3650 then it drops to 300 @ 4200. that's not real impressive unless you compare that band directly to another similar lsX. from start line with equal gearing more torque accelerates quicker. then a small amount of time after i shift the higher revving higher HP car has higher MPH.(not bragging just illustrating my philosophy)

    i am still cars ahead. but losing ground. etc etc etc. look to 1968 428CJ stangs in SS. they owned E.T. but not MPH or HP. i follow that to the letter.

    so i am willing to submit that LS will always own HP unless i switch to GT heads. but with superior velocity and low to mid rpm filling that goes with it i win to a set distance point. add vct and HP is in the equation, just to a lesser extent than LS2,ls6,ls7. but LS1 had better watch out. they do not own flow that much over me. and certainly not torque.
    now if you take another shot i will start up again.

    that text is not out of context, it is a post concerning seat angle and it's applications. nothing more.

    there is nobody i can quote to an unreasonable person that will satisfy his inability to give in to another idea. i have seen both sides high flow low velocity and lesser flow gigh velocity. a combination of chasis and gear can take advantage of both.

    note the CUP rule limiting gear. for the high revvers.
  6. I've been watching this thread for awhile. I'm a Chevy guy who did some drag stuff, built and raced an MG sportscar at Daytona, Sebring. West Palm and Roebling. Now I own an F150 and autocross a 99 Musatng. Over the years I wrenched a Pro stocker (back when they were a lot more "stocker" than pro. I got to tell you, I've enjoyed it (the thread)quite a bit, The petty crap got old, but other than that it's been great. One interesting thing on the MG, they run an almost flat head, and had a dished piston (sort of a hemi in reverse) I always thought that if I was to ever have the bucks to build "my motor", it would use this set up over the conventional type of piston dome-in-head design that we used now. BTW, IMO the elephant motors came along the same time the 426 Hemi did. Sox and Martin owned pro stock with theirs, Nicholson's 427 SOHC was usuallythe runner up, but never ever race the Grump in a match race and expect to win.
  7. You keep making reference to your impressive torque out of your 5.4. And you keep saying that the LSx motors need cubes to make power. So by your own reasoning, how do you explain the 100 HP difference in the 324" Impala SS LS1 based motor that makes 303 HP and the 364" LS2 motor that makes 400 HP? You will not get 100 HP out of a 4.6 or your 5.4 by merely adding 40 cubes.

    If we are going to compare cars, let's keep this apples to apples as much as possible. You keep comparing your 5.4 to a 5.3 that comes in a passenger car. That is clearly not a reasonable comparison. Let's keep this a comparision between each makes performance cars.....Mustang and GTO. Quit comparing your 5.4 to a Chevy Impala motor. That's like comparing a Camaro to a Taurus. You say you make 325 RWTQ with a few tweaks.....well the LS2 bone stock makes just as much torque and 100 more HP to the wheels than your 5.4 with only 34 more cubes and zero tweaks. Stick only a cam in that LS2 and hasta la vista. Torque is for dump trucks, HP under the curve wins races:

    View attachment 412668

    GM High Tech Performance GTO Article

    And I also believe that you have a habit of taking things out of context to prove a point. That article by Dave Vizard was clearly talking about NASCAR Nextel Cup motors.

    Please explain in English.
  8. What can I say but you right and you are wrong. It is toque that wins race and accelerates vehicles. But it is the toque where the rubber meets the road. So how does and engine with less toque but more HP do this. Because HP = Torque * RPM/ 5252 we can replace toque with RPM's to get more HP. If we have enough RPM we can run a lower rear axle ratio which multiples our toque before it gets to the wheel. Giving us better acceleration.

  9. I did not close this thread for that exact reason. I think there is a lot of interesting stuff being posted here by laserred.
  10. Stan, I think you are on to something with the HP/Torque topic. I have always looked at it like this:

    There is one thing that gets a car down the track and that is power. In mathematical terms, power is defined work divided by time. Work is defined as a specific amount force causing an object to move a specific distance. So in essence we have P=(F*D)/T. We obviously know how to measure the time and the distance, and the force used in this particular instance would be torque. Torque is simply a measurement of angular force. It is calculated by taking a measured linear force and then multiplying that linear force by a specific radius. We gearheads talk about this as lb-ft.

    Since a common way of looking at horsepower involves a function of RPM and torque, HP=(Torque*RPM)/5252, torque is simply but a part of a much bigger scenario…..power.

    As soon as the green bulb is lit and we begin to launch our car forward, it is power that is creating that acceleration and it will continue to be power that propels us all the way through the traps. Torque is simply a piece of the puzzle, although an important piece, still just a piece. Since torque is intrinsically related to RPM and ultimately horsepower, it is horsepower that actually is responsible for getting the job done at the end of the day. For us to say torque alone is what we should focus on when building a motor, or to even say that torque wins a race is to disregard the actual reality of the physics involved in getting us down the track faster than the other guy.

    Like Stan mentioned we could focus on making a torque monster and gear it with a numerically lower rear gear than usual , but as we approach the mid range RPM’s and ultimately at around 5200 RPM’s, we would start to dramatically lose the power efficiency of this setup. What happens at around 5200 RPM’s is that the rotational inertia of the motor begins to surpass the raw angular momentum rate of change (torque) potential of the motor. This is where you see the rising HP curve start to rise above the down falling torque curve on a dyno graph. It is with this expectation that the vast majority of drag race engine builders will focus on making horsepower rather than torque. It is a more efficient way of making power, we can gear the car to take full advantage of torque multiplication throughout the RPM’s, and thus a more efficient way of accelerating the vehicle.

    My nickel’s worth. What do you guys think?

  11. Well done. I made a point to stay out of this thread, but I must commend you on a very well written point.

    And if Torque was the sole unit that propelled one down a track, you would see more electric motors that gas...

    How about 735.57 ft/lbs of torque @ 1785RPM? (thats 250HP) HAR HAR HAR!!!

    (stock number 5N354)
  12. Back when I owned a small welding/painting business, we used to work on office building parking garages. I would usually make friends with the building engineers. One time a building engineer asked me to design and build him a trolley hoist type gantry and a crane so that they could get the huge A/C blower motors down off the 12 story roof mechanical room when they needed to be serviced or replaced. Those were just 70 HP electric motors but they were about the size of keg and they weighed 800 lbs. I can just imagine how heavy a 250 HP electric motor is.:crazy:

    What is impressive though is how some of these diesel guys are cranking out some fast rides. Technology has come a long way. There are lots of Bubbas out there with 11 second F-350's now........a few I know :D

    Diesels are starting to make a statement in road racing as well.
  13. please explain in your own words how a 68 stang 428CJ won superstock against cars with a better HP to weight ratio.

    it had a small hp disadvantage and a large low end torque advantage. area under the curve as you said. all of those other baitings mean nothing.
  14. Bill what about the above did you not understand. Let me try a different way. If the HP increase does not come with an RPM increase that will let you run a rear gear that gives more rear wheel torque then it will lose. To know who should win you need to know for both vehicles
    max torque / rpm
    max hp /rpm
    trans gear ratios and power lose in each gear
    rear end gear ratio and power lose
    frontal area and CD
    Tire Diameter
    probably missed some things
  15. what about"you don't have anything you can teach me" do you guys not understand. you are young kids with a lot to learn
  16. Every body still has things they can learn. But I am not a young kid. I was drag racing before Ford build 68 stang 428CJ. The picture is of me in '67 working on a 327 + 0.060 chevy with alum rod, alum rocker arms, engle roller cam and 2 x 4 carbs.
  17. Don't you ever get tired of pretending to be a 41 year old man who has all this experience working on cars. Everybody here (as well as the Thunderbird – TCCOA forums) knows you are just a young kid pretending to be someone they aren’t, all the while throwing around your less than desirable attitude. Grown up men do not speak as illiterately and naively as you do….and don’t bother saying that’s just the way you type. Why don’t you get off your parent’s computer, go out and get a job, and go to school where you belong. You know if you would just admit that you are a kid….and would show a genuine interest in learning from those who actually have been around cars for awhile….people might give you a chance. But somehow I just don’t see that happening anytime soon.

    If you keep up your antics here, you are just destined to be trampled over just like you are over on TCCOA. I have to admit….we actually look forward to reading your posts now here in the shop. Over on TCCOA, it’s absolutely hilarious how you are constantly run out of threads like Michael Jackson in a high school boys locker room….LOL.

    It’s just a matter of time before you get sent to banned camp. :D

  18. Stan I cannot see your picture....but I would like to. Maybe you can re-post it?

    One of my good friends has a 1966 Ford F100 Pickup with a 428 Cobra Jet in it. It is a fun ride. :D