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24v DOHC V6...

Discussion in '2005-2010 V6 Mustang Tech' started by WYLDHorses, Feb 22, 2005.

  1. V604mustangjoe

    V604mustangjoe New Member

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    what are the flow rates on the SOHC heads and the DOHC heads for the 4.0.

    DOHC are the crossworths.

    if lets say the DOHC heads can flow twice as much air at the same PSI as the SOHC heads then you double your hp.
     
  2. Dennis1417

    Dennis1417 Well-Known Member

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    If only it were that simple. :rolleyes:
     
  3. V604mustangjoe

    V604mustangjoe New Member

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    its pretty close to that.

    if you have a turbo at 10 psi, and you make 400 hp, then you go to 20 psi nothing else changed you would get like 600 hp about. same goes with head flow rate.
     
  4. goldenstang00

    goldenstang00 Chebby Guy

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    RIIIIIIIIIIIIIIIIGHT! :rolleyes:



    Do you know what a piston is? Better yet. Have you ever even seen a car? :confused:
     
  5. V604mustangjoe

    V604mustangjoe New Member

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    umm do you even have a mustang, or have you ever seen or driven in one?

    Yea and ever hear of the 350Z, it makes aout 300 HP with a 3.5 litre DOHC v6, the whole secret to hp is getting air ina nd out of a motor, and a key part of that is hte Heads, so i dont get what you dont understand?
     
  6. V604mustangjoe

    V604mustangjoe New Member

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    yea, if you think a SOHC to DOHC is hard, they did a OHV corvette way back when and converted it to DOHC heads, so its not all that hard. They just used a timing belt since it would be too hard to make a timing chain since a timing belt cover isnt as hard.
     
  7. goldenstang00

    goldenstang00 Chebby Guy

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    I used to have a mustang n00b. Step down. :cool:

    The basics of an engine are getting air in and out. Thats what makes hp. DOHC doens't exactly mean its gonna make crap loads of hp. Its gonna need custom grind cams to go with the heads.

    Its all about duration, lift, and lobes. I'd go on but your know a hell of alot more than me so I'll let you figure it out.

    BTW. I'd rather have OHV. Give me two big valves flowing the same if not more than 4 small ones. ;) Besides, they are easier to work on.

    TOP fuel dragsters use OHV. They make over 1,000hp per cylinder. :eek:

    But in the end its not which valvetrain you use. Its the tuning of the motor. Just swapping parts is not gonna make hp. ;)
     
  8. V604mustangjoe

    V604mustangjoe New Member

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    yea i agree OHV is easier to work on and its better for full time high output motors like boats and race cars, but for daily driving DOHC has its advantages, like better gas mileage since you can vary the timing and have some valves closed at lower rpms. And usually DOHC uses stupid timing belts that break and ruin your whole engine. 4 mediumvavles can let more air flow in better than 2 big ones since they let air in at differt sides of the cylander.

    just saying for a dialy driving fast car i'd prefer a 4 vavle motor over a 2 valve, but i also want displacment with it and not some tiny ass jap engine.
     
  9. KTBug

    KTBug - Kris -

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    Ok guys, we're getting a little off topic here.

    4 smaller valves allow a higher velocity through the heads. 2 valves can flow just as well as 4. In order to do that though, the 2 valves have to be larger. Larger valves = slower velocity. Faster velocity usually equates to more torque and that torque should generally be spread over a wider RPM range.

    Anyway, back to the Cosworth engines.....
     
  10. 6stanger

    6stanger poor starving college kid

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    very interesting
     
  11. 03f1504x4

    03f1504x4 New Member

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    Not to mention, resistance to detonation due to the center plug design. Or the increase in valve area? It also has a superior combustin chamber.

    I agree with speedkills, about the heads not going to make much difference between a 2.9 and the 4.0. Has anyone have these things flowed at a flowbench? Suppose you swapped a set of e7te's onto a 393 windsor...do you think you would make more power? It seems to me you would run out of head really quickly...You would make a lot of torque but its going to shift your powerband to the point you would prob make peak hp at about 4k and your pk tq at 2500....
    Yes cams will make a difference..duration and lift....btw..are only part of the story...the big diff is flow at lower lifts for cyl filling.

    "TheStang00 speedkills = idiot... not only will they flow better... but u can stick another cam on there. think about it. just look at the SN95 v8's for an example, mustang gt= 260hp 2v sohc 4.6l. mustang mach1= 310hp 4v dohc 4.6l. only difference is the heads and dohc."

    HMM...that the only difference? number 1....those heads were both designed for a 4.6..not one for a 2.9 and the other for a 4.0.
    Just so you know..they also have a diff intake manifold, exhaust setup, cam setups, not only the fact that there is 2...bit lift and profiles....They have different short blocks, throttle bodies, injectors, and tunes as well. One is tuned for 87 the other is tuned for 92. Maybe you should take a internet visit over to modularfords.com...or maybe read the sean hyland motorsports book on the modular engine family.

    ok..now that is said...i would still enjoy seeing this swap done...If the heads FLOW as well as they are rumored to, then i could see..maybe 250-270 whp n/a. Of course...morana racing ad super six motorsports both have 2v based pushrod v6's that have eclipsed that level. Good luck with the swap.. :thumbup:
     
  12. V604mustangjoe

    V604mustangjoe New Member

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    why not just custom fab 24 valve DOHC heads from scratch, take the blue prints to an engine block similiar to that of the 4.0 (i am assuming its related to the 2.9) and blow it up on the computer, make the valves bigger, heck copy some other 24 valve high output larger motor head designs like the 350Z nissan 3.5 DOHC 24 valve motor or something.

    Then have them custom fabbed, (not saying htis would be cheap nor easy, but still something cool i'd deffinently do if i won the lottery, then sell them for dirt cheap for all 4.0 v6 mustang owners :) ).

    Why not make a SOHC 24 valve head system and utilize a variable valve timing system like that of the one on the 05 GT 3 valve motor.

    Just copy the VVT (variable valve timing )system on the ford 4.6 v8 24 valve SOHC,

    (yes i know this is outlandishly complicated, but not as outlandishly stupid as modding a 1.6 litre honda civic)

    but if you could make a 24 valve SOHC vvt head system like that of the 3.2 litre acura TL motor for this bigger 4.0 engine i am sure you could get some impressive n/a power numbers.

    Acura TL has about a 280 hp engine, 3.2 litres, thats about 350 hp if the motor was expanded to 4.0 litres. Now i am sure there is a simple way to do all this mess some how. I'd imagine the hardest part would be tuning it, and getting the cam timing to work right.

    hell if you did all this work and got it working right i bet you could be rich selling the design to ford to use as a replacement to all their v8 powered suvs (remember the gas prices).

    What about the duratech motor? Is that related in anyway to the 4.0 SOHC 12 valve?

    duratech motors are pretty mighty, or the vulcan motor in the probe/ svt contour, thats a little 200 hp 2.5 litre! Imagine making that 4.0 litres

    I know of a place here in michigan that makes prototype carbon plastic intake manifolds for the auto industry, you give them the design and they make you any manifold you want. If you get some engineers together to make these heads and come up with a radical intake manifold to go with it.


    I'd rather pay 3 grand for 350 hp n/a than for 500 hp blown power. I dont know why, it just seems cooler to have a motor that looks like a stock v6 mustang motor with no snails under the hood and sike people out when i blow by them.
     
  13. 03f1504x4

    03f1504x4 New Member

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    For the money that would cost..with the return....youd be better off just hiding a nitrous system. The vvt on the 4.6 and 5.4 require a new block to get a system like it, they have internal oil passages that actuate the vvt. You likely wouldnt gain much from it..youd be better off stroking it and getting the heads ported. If you were going to invest money to get heads designed...stick with something that follow the stock design. Trying to redesign the wheel is fun to think about...but in reality its going to end up another pipe dream. Trust me..i have many of those. Stick with a SOHC design...with 2 valves per cyl... and make them flow more, smoother runners with more volume and a better combustion chamber.. have a cam matched to it. You can even try a canted valve head setup, or mock the hemispherical heads...A good intake manifold would help too. Hell..send a message to ARAO ENGINEERING. They have some badass heads that are designed for pushrod cars but have 4 valves per cyl. I'm sure if you were willing to invest the money, that they could help out. www.araoengineering.com

    Corey
     
  14. V604mustangjoe

    V604mustangjoe New Member

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    holly crap they got 4 valve heads for push rod motors, what do they do have 1 push rod control 2 valves with a special rocker arm?
     
  15. SpaceCowboy

    SpaceCowboy New Member

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    we don't have a timing belt????
     
  16. 03f1504x4

    03f1504x4 New Member

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    Yup.
     
  17. nealgobert

    nealgobert Active Member

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    Speaking of multi-valve pushrod engines, has anyone had the opportunity to look at the V8 6.0 Powerstroke Diesel? I know it's kinda off topic because it's a diesel, but it is 32 valves, pushrod actuated.
     
  18. 03f1504x4

    03f1504x4 New Member

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    Wow...i didnt know that...thanks for the info.. :thumbup:
     
  19. SpeedKills

    SpeedKills New Member

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    I have read this thread again and though about it. I am not 100% sure, but those of you that say that 4 valves make for better velocity and more lowend tq then 2 valve head with similar from numbers aren't exacly correct.

    You will actually have lower air velocity, with 4v heads then with 2 valve heads that flow same numbers. Why???

    Air velocity is inversly proportinate to cross sectional area. The more x-section is the slower the air has to flow. Agreed??? Can we also agree that the wall of the runner is what causes drag? And the more there wall there is for a x-sectional area the more dragg there is.

    If you take 2 tubes and 1 big tube and they will have same combined x-area, then the 2 tubes will have also more wall then the single large tube. What this means is that in order to actually achive same flow rates in both 2 tube and 1 big tube, the 2 smaller tubes have to have bigger combined x-area then then the big tube. Sense they will have more x-area velocily in them will slower causing less lowend torque.

    That said, because there are 2 valves and sometimes 2 runners per side in a 4v head, variable valve lift or timing or IMRCs can close the off the second runner/valve at low rpms and then you only have 1 small tube and that gives allot more low end torque then a single big valve or single big runner in 2V head.

    If cosworth 4v heads don't have IMRCs or VVTiL built in, there is little point of getting them if you drive on the street. Yes, 4V heads can be made to flow much better then 2v heads, so they are great for racing.
     
  20. NavyStang05

    NavyStang05 Boostin' Six

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    Dude, you're making the mistake of confusing air velocity with mass flow rate of the air. The thing that is important in any type of engine analysis is the mass flow rate, or the amount of air per second that can be moved. While 4v engines will have a smaller velocity, they will have a larger mass flow rate available than their 2v competitors