383 Stealthram

Discussion in 'Engine Combos and Dynometer Database' started by CWash2, Sep 2, 2021.

  1. B&R Racing

    B&R Racing reliable source of info

    383 SBC Sounds More Impressive Kooler when shooting the sheet with Fellow Car Guys. Even around Pontiac 455 guys like me we know they can Run Hard
    Anything LS X Is unimpressive unless its Twin Turbocharged to 2000 Hp but we know that Fun won't last long unless there is $10,000 into the Fuel system and EFI Full Pro Mod Door Slammer Street Outlaws style True.
     
  2. B&R Racing

    B&R Racing reliable source of info

    It's such a Wide LCA 113.
    It might run on 87 octane gas A-ok.
    I am a Carburetor guy wont run any wider than 110 LCA.
    Like 108, 106, 104, 102.
    108 LCA my usual Favorite.
    Get up around 1000 Hp Nirmal Aspirated 112-117 LCA Can make more power have to spin up 9000 rpms steady often.

    Best way I know to see if Higher Ratio Rockers will work help is to use an Engine simulation.
    Need the actual valve opening and closing events off your supplied camshaft card.
    IVO, IVC.
    EVO, EVC.
    Can be listed at .006" lift.
    .020" lift.
    Most often at .050" lift and preferred to run an accurate as possible engine simulation.
    Higher ratio Rockers like from 1.5: 1 to 1.6 or 1.65:1 usually helps but not always.
     
  3. B&R Racing

    B&R Racing reliable source of info

    We go by calculated dynamic compression ratio in past here.
    I have found it's not as critical as we thought in past.
    8.0:1 on 93 is calculated ideal.
    I have found 7.0:1 - 7.5:1 Dynamic is A-ok on street cam profiles pump gas.
    Still performs stellar power torque allover.
    Zero chance of detonation issues not pushing to 8.0:1 exact.
     
  4. CWash2

    CWash2 Member

    Thanks for replying. I am sorry if I may be repeating stuff that has been hashed out before. But suppose every doctor only treated each type of patient only once and then expected everybody else to just read all his posts and find out how to cure their ills? Now my head is spinning. Also a couple things I said were in error. My heads have 72 degree mounting bolts but 75 cc chambers. Also my cam is CC Nitrous cam grind with 224/236 instead of 237/236. My lift numbers are .502/.520 on a 113 lsa however. So please let me ask this question: With the 195 Eliminators, I was told that they flow excellent on the exhaust side so my duration split would probably be unnecessary. Now since the cam does have a wider lsa and less duration than some cams listed here, can I assume that unnecessary does not mean detrimental? Well I do want the cam to work well on the street. BUT, if I ever do decide to fool around with Nitrous, this will probably be the only engine I may get a chance to do that. So has anyone here used a 383, 195 eliminator heads and this or a similar cam. I have had this car in my garage since 1995 only taking it out to wash it. The 305 tpi it came with was able to do 15 second 1340 times. I have the time slips to prove it! I have posted several times in the last couple days. The nitrous cam to me seems to be a real purpose built street/strip cam. Namely wouldn't it be better on the street (with 383 and 195s between 9 and 10:1 compression) than most cams, and better on the track (especially with nitrous) than most cams. I am willing to sacrifice high rpm performance over 6000 because I literally did not build the motor with it intended to rev far past 6000. I like it's 113 lsa cam timing for sound, driveability and brake ability. I don't want an obnoxious idle. So, I have tri-y headers and I need to find a quiet muffler ( no flow master no way no how). I really don't want it to rattle dishes inside the house. What I want it to sound like is HEY! somebody is trying to sneak a really fast car down the street. Which way did he go? Who? That car! Never mind... Gone...

    Hasn't someone used the nitrous cam? Swapped it out? Swapped it in?

    Should I use 1.6 rockers? All, or just the intakes? Would More intake lift cause problems here or could it maybe work to make the cam more normally aspirated leaning than nitrous leaning? Which muffler?
     
    B&R Racing likes this.
  5. B&R Racing

    B&R Racing reliable source of info

    In the
    In the past here Cams were purpose selected.
    Usually Crower chose for 383 or 400 ci SBC.
    Was after the Perfect Dynamic compression calculator 8.0:1.
    That took precedence over anything else.
    Pump gas 91-93.

    But then we have Mud Truck Racer come along with a Supercharged Roots Blown SBC on E85 fuel.
    Huge Race Cam profile used, tamed down a hair later but still red hot, Dynamic compression given a little thought, but tossed out the Wayside in the end because High End 800-1000 hp the goals.
     
  6. B&R Racing

    B&R Racing reliable source of info

    If you bought the Nitrous cam use it.
    Try different ratio Rockers and shift the ICA and ECA around degreeing the camshaft in.
    Best way to predict ahead of time is using engine simulations.
     
  7. CWash2

    CWash2 Member

    Here goes;
    224/236@.050
    .502/.520 lift
    Lsa=113
    Int. Centerline=108
    Lobe lift int. = 0.335
    Lobe lift exh. =0.347

    Intake centerline=108


    The following are at 0.006;
    Int. Valve open = 30 BTDC
    Exh. Valve open= 82 BBDC
    Int. Valve closed= 66 ABDC
    Exh. Valve closed=26 ATDC

    2,000 to 6,000 rpm range

    With flat pistons at zero in the hole and 381 cubes (3.75 x 4.020) with the 195 Eliminators and the above cam, what does the simulator forecast?
     
    B&R Racing likes this.
  8. B&R Racing

    B&R Racing reliable source of info

    I am going to have to do an engine simulation for you later tonight.
    Takes a while to complete.
    I have to look up the AFR195 Heads and make an airflow file. Like using Independent tests from Stan Weisse his website.
    Better than Factory tests given I find or published online.
     
  9. CWash2

    CWash2 Member

    Ok thank you. I just can't predict how all this relates. In terms of horsepower and torque, I only have as a point of reference a 305 tpi motor with at most 220 horsepower. Though sort of quick out of the hole for the first 30 feet there was also a good throaty exhaust note. But there was more bark than bite. Now I am working with a motor that should be more than twice the horsepower and probably 60 or 70 percent more torque. So with cam and converter and transmission planetary, the elapsed times should be much quicker. So I understand that if I had a motor that went to 8000 rpm and 800 horsepower it would require different gears, roll cage, slicks, etc.

    But I want street radials and no roll cage. I want at best 7.50 times in the eighth. Or as close to it as I can get without giving up street driveability. So I wonder about the great abundance of torque and horsepower with a stealthram 383 with AFR 195 eliminator heads, headers, nitrous cam, etc. I am hoping that I won't already have too much torque for my chassis. I plan on just subframe connectors and bushings, tubular trans/ rear end brace (I forget what it's called at the moment). So I am just wondering if the 1.6 rockers on the intakes would improve breathing dwell on the intake side to more closely match the cam to the heads. After talking to AFR, I gathered that the assymetric superior exhaust flow of the heads like optimally at most a 6 degree split for optimal torque down low and still good top end. Well I don't need optimal performance beyond 6500 because I am not trying to often rev past 6200 because I don't have a rev kit for the heads and my short block is not built for 6500. If 5900 or 6000 get it done then all well and good. I just don't know how much margin I need for springs. Especially if I use nitrous a half dozen times a year. At 5900 to 6100 shifts with the .532 intake flow, this ought to still make good power on nitrous while at least not hurting normally aspirated performance while hopefully staying below 6500. Hopefully, this would increase midrange torque when trans shifts and help make power I can use under 6100 or so rpm. Realistically there is not that much difference in flow on the 195 heads between .500 and .550. (Something like 4 CFM which is like 1 percent.) I'm just wondering if I will need to change to the 8019 springs on the heads (Or just for the intake valves. They are bigger and heavier after all). The càm is .502/.520 lift, so going to .532 on the intakes confused me as to what spring pressures would be required. Maybe AFR or Comp will help me with spring choice. Hopefully the simulation will tell me which rocker ratios are best considering what I am trying to achieve.
     
    B&R Racing likes this.
  10. B&R Racing

    B&R Racing reliable source of info

    I was Welding all day long into the night.
    Have about 1 hour of Fabrication and welding Tomorrow morning then done.
    I haven't got to your Engine simulation yet.
     
  11. CWash2

    CWash2 Member

    MAy I add that I have 7/16 studs and the 8029 spring upgrade. I didn't want any problems with the cam either way. Especially with nitrous.
     
  12. CWash2

    CWash2 Member

  13. CWash2

    CWash2 Member

    Also the heads are not angle plug.
     
  14. CWash2

    CWash2 Member

    The heads ARE angle plug. They are NOT angle bolt for the intake.
     
  15. B&R Racing

    B&R Racing reliable source of info

  16. B&R Racing

    B&R Racing reliable source of info

    AFR 195 Eliminator heads come in different versions.
    2.02 intakes, 2.05 & 2.08 inch intake valves.
    Choosing 2.02, they show 74-75 cc chamber volumes
     
  17. B&R Racing

    B&R Racing reliable source of info

    No 2.05 intakes.
    David Vizzard has an entry.
    Seems a little high the flow figures but going to Trust Vizzards tests he has been on You Tube the last 1 year making videos
     
  18. B&R Racing

    B&R Racing reliable source of info

    Vizzard is one of the few left paying attention to low lift flows.
    Most Everyone in Race world today work with.500" -1.000 "valve lifts
     
  19. Grumpy

    Grumpy The Grumpy Grease Monkey mechanical engineer. Staff Member

    stealth ram intakes really respond to careful port work being done,
    with a noticeable boost in flow vs out of the box, condition.
    especially if you match them to those AFR heads, and a decent cam with at least a 220-230 intake duration, and about a .480-.520 lift, and headers

    http://garage.grumpysperformance.co...-stock-tpi-engine-components.1509/#post-74581

    http://garage.grumpysperformance.co...intakes-and-radiused-inlets.15373/#post-90199

    http://garage.grumpysperformance.com/index.php?threads/ideal-tpi-build.12203/#post-59273

    http://garage.grumpysperformance.com/index.php?threads/can-you-get-there-with-tpi.10494/
     
  20. B&R Racing

    B&R Racing reliable source of info

    Going to assume it's a Hydraulic Roller profile.
    They haven't made a Solid Flat tappet Nitous csm profile in over 20 years
     

Share This Page