Blown SBC

Discussion in 'PSI Superchargers Tech Questions' started by Jap Tin, May 31, 2008.

  1. Jap Tin

    Jap Tin New Member

    Joined:
    Apr 9, 2006
    Messages:
    49
    Likes Received:
    0
    Looking to convert a N/A gas SBC to blown alky. Donovan block, 400 mains standard cam heigth. The crank is 3.8" bore 4.165" . Brodix 18X heads. Carrillo rods, 14 to 1 compression. What to keep, what to get rid of , and what to get. Is bigger better when it comes to blowers? Looking for around 1200 hp.
     
    #1
  2. RLPRACING

    RLPRACING Member

    Joined:
    Mar 16, 2007
    Messages:
    79
    Likes Received:
    2
    Need to lower compression to the 10 or 11:1 range, change timing chain to gear drive, some killer valve springs for the higher pressures, biggest push rods you can fit, some very good aluminum rods, we use a crank with a big block snout and also use a crank support. Bigger the blower the less overdrive you have to turn it to make the same pressure but with less heat. That and a few other odds and ends will support more than the 1200hp you are targeting but it is $$$$$$. We are just starting and have went 4.26 on a very safe setup at 1900lbs. How fast are you wanting to go?
     
    #2
  3. mbaker3

    mbaker3 New Member

    Joined:
    Dec 30, 2007
    Messages:
    270
    Likes Received:
    0
    RLPRacing,

    Where did you get your crank? I have spun the guts out of three high dollar dampers. Been told that if I don't have a two keyway crank, I am wasting my time.
    So far, I have not been able to find a machine shop that will cut the second keyway into my crank. I am now looking to buy a new one from someone, somewhere.
    Being new to blown alcohol, I just don't have the vendor contacts that I need.
    Thanks ahead of time for any help that anyone on this forum can provide! Hope this post doesn't break this thread!!

    Dave Baker
    Lakeland
     
    #3
  4. Fuel Cars

    Fuel Cars AA/AM

    Joined:
    Aug 20, 2003
    Messages:
    306
    Likes Received:
    8
    mbaker3, I would say to get rid of the dampener and get crank hub.
     
    #4
  5. Torque Monster

    Torque Monster New Member

    Joined:
    Mar 10, 2008
    Messages:
    8
    Likes Received:
    0
    406

    I ran blown small block for years. 406 dart iron block, crower forged crank, super 70 manley rods a (don't make anymore) AFR 227 cnc heads, 285/295 cam with .730 lift chromoly rockers with stud girdles, manley 5/16 pushrods (could be a problem on some other design head), 12.5 to 1 compression, Littlefield hi helix retro blower at 35%, 110 pump, bird catcher. 2300lbs converter powerglide door car, low 4.50's. I found the critical parts to be, big block snout with crank support, double keyways (one with 1/4 hardened stock) will eventually shear off otherwise, 14mm belt, timing chain was fine, big block wrist pins (very important), titanium intake valves and inconnel or super alloy exhaust valves, MSD mag or Mallory Supermag, had no trouble with this valve train. Put 130 passes on rods. I hope this helps.:)
     
    #5
  6. mbaker3

    mbaker3 New Member

    Joined:
    Dec 30, 2007
    Messages:
    270
    Likes Received:
    0
    Paul,
    I completely agree. But with my SBC, running a cam driven fuel pump, there is only about 6-3/8" clearance between the damper and the flange on the Enderle fuel pump. Every crank hub that I have seen is a lot larger diameter than that. That is why I have stuck with a damper. I need the timing marks.

    Again, I am new to this and I don't want anyone to think that I am the "know it all". I am not! I am just trying to find a combination that will let me go to the track and race.
    The people in this forum have already gone through what I am going through now, and are chuckling!:)

    Wish me luck, I will get there eventually!
     
    #6
  7. mbaker3

    mbaker3 New Member

    Joined:
    Dec 30, 2007
    Messages:
    270
    Likes Received:
    0
    Torque Monster,

    Absolutely great information on what you used to run. I don't have a mag drive. I am still using the MSD billet dist.

    The value of this forum is that most people involved are willing to share a little of their info to help us "newbies" :)

    Thanks so much for everyones time and information!

    Dave Baker!
     
    #7
  8. Fuel Cars

    Fuel Cars AA/AM

    Joined:
    Aug 20, 2003
    Messages:
    306
    Likes Received:
    8
    Dave, before I went with a smaller crank hub, I had the same problem. I changed my pump drive extension to a 6 inch one and now I have plenty of clearance.
    A picture is worth a thousand words so here's 2000:
    [​IMG]
    [​IMG]
     
    #8
  9. RLPRACING

    RLPRACING Member

    Joined:
    Mar 16, 2007
    Messages:
    79
    Likes Received:
    2
    Our crank is a Callies and it does have the double keys with the BB snout. We don't run a damper either and even with the raised cam block, we chose to belt drive our fuel pump. The other "different" thing we are doing is use the MSD 10 instead of a mag, 8" set back on the blower so the crab distributor is under the blower.
     
    #9
  10. mbaker3

    mbaker3 New Member

    Joined:
    Dec 30, 2007
    Messages:
    270
    Likes Received:
    0
    This is great info! Thanks for taking the time to respond. I'm not sure I can accomplish this because I am already trying to put 10 Lbs in a 5 Lb. bag!;)

    I have this blower motor in a '86 S-10. My 4" pump extension has probably put me at the limit! I am only about 1/2" from the radiator.

    I like your idea of the extending the pump. I will have to look into moving the radiator forward.

    Thanks,
    Dave Baker
     
    #10
  11. WJ Birmingham

    WJ Birmingham New Member

    Joined:
    Oct 1, 2007
    Messages:
    457
    Likes Received:
    1
    [​IMG]

    If you have access to a mill, you can make your own clearance...

    Note where the dual pump drive has been milled. Prior to the dual pump drive, we milled the flange on the enderle itself.

    So long as you're not using a Marmon flange, and have at least 3 bolts to attach it, should be good to go.
     
    #11
  12. Alkydrag

    Alkydrag Sr. Dragster

    Joined:
    Dec 24, 2003
    Messages:
    351
    Likes Received:
    1
    We run a 427 SBC blown alcohol. HH 14/71, with a mini retro and Mallory mag. I would run a mag for the reason that as cylinder pressure increases, the mag won't give up like electronic ignition will. We also don't run a radiator, we don't have any cooling issues whatsoever. No balancer. The blower belt will absorb the harmonics. And we run a Jesel belt drive with a spud off the cam for the pump. The crank is a Callies with a BB snout and an RCD crank support and dual keyways with a dry sump pump driven off the crank. The heads are Brodix -12's that are filled and a Dart tall deck iron block. We've run 4.40 @ 170 in the 1/8 mile. Best of all, there are no one off custom billet parts at all. Everything is off the shelf.
     
    #12
  13. Jap Tin

    Jap Tin New Member

    Joined:
    Apr 9, 2006
    Messages:
    49
    Likes Received:
    0
    Looks like I keep the block and thats about it. I have a friend with a tall deck dart aluminum sbc block I may talk him out of it and build a blower motor with that and leave the 414 N/A motor alone.
     
    #13
  14. Torque Monster

    Torque Monster New Member

    Joined:
    Mar 10, 2008
    Messages:
    8
    Likes Received:
    0
    Wow

    We run a 427 SBC blown alcohol. HH 14/71, with a mini retro and Mallory mag. I would run a mag for the reason that as cylinder pressure increases, the mag won't give up like electronic ignition will. We also don't run a radiator, we don't have any cooling issues whatsoever. No balancer. The blower belt will absorb the harmonics. And we run a Jesel belt drive with a spud off the cam for the pump. The crank is a Callies with a BB snout and an RCD crank support and dual keyways with a dry sump pump driven off the crank. The heads are Brodix -12's that are filled and a Dart tall deck iron block. We've run 4.40 @ 170 in the 1/8 mile. Best of all, there are no one off custom billet parts at all. Everything is off the shelf.
    __________________
    Tony Ramos

    Thats a hell of a MPH. I only run 169 on a 4.27. What is the car weight?
     
    #14
  15. mbaker3

    mbaker3 New Member

    Joined:
    Dec 30, 2007
    Messages:
    270
    Likes Received:
    0
    WJ, Dual Pump Drive

    WJ,

    It's weird, yesterday when you posted, your picture didn't show up in the post. I was desperately looking into Paul's post (Fuel Cars) to see the milling that you were talking about. Now, seeing the picture that you posted, I can see what you were talking about. :eek:

    Because of the other responders, I guess the route that I need to take is to get the SBC crank, have the BBC snout on it. Double the keyways and I will eliminate the damper and go to a hub with the degree ring.

    Thanks again to all of the members that have taken the time to respond to my questions and comments. Without your participation, this site wouldn't be as valuable as it is!

    Thanks,
    Dave Baker
     
    #15
  16. Alkydrag

    Alkydrag Sr. Dragster

    Joined:
    Dec 24, 2003
    Messages:
    351
    Likes Received:
    1
    The car weighs 2550 after the run. We consistently run 165-170 to the
    1/8th. The Hemi's run about 170-175.
     
    #16
  17. WJ Birmingham

    WJ Birmingham New Member

    Joined:
    Oct 1, 2007
    Messages:
    457
    Likes Received:
    1
    No need for embarrassment... The interweb is sometimes screwy.

    This site is killer for good info. It's nice to have a place to go where people are willing to share information. Lord knows this sport is expensive enough without sharing.
     
    #17

Share This Page