Comp engines

Discussion in 'The Comp Buzz' started by cory, Jan 11, 2011.

  1. B/AA 529Y

    B/AA 529Y Member

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    Let me sell you my Mopar PS motor for $30k. It's apart now, and can be rebuilt anyway you want it.
     
  2. mark markow

    mark markow Member

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    8.2 deck is the aurora block. usualy in the low 300c.i. range.
     
  3. C Tanksley

    C Tanksley New Member

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    Cory build a 400 RO7 ci motor for B/D . We have a car to put it in there will be no bullshit we will take it to the pole first time out . We have been running a stick dragerst for 5 years our clutch man is the best, he only needs 2 runs and is dialed in . If it makes enough power .
     
    #23 C Tanksley, Jan 13, 2011
    Last edited: Jan 13, 2011
  4. Rob Harrison

    Rob Harrison Well-Known Member

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    The suggestion that a "Cup" motor would be in the same stratosphere as a Comp motor, has got my attention. What about the acceleration rate, low compression, etc. ? Take a cup 357, put it in a S/M, is it -50 under? pretty scary if it is.....
     
  5. 377 D/A

    377 D/A Member

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    thank you rob. all of those cup guys think that doing drag stuff is like falling off a log but its not. i don't mean it negatively it is just apples and elephants thats all. their stuff is about 120 south of being 50 under
    ian
     
    #25 377 D/A, Jan 13, 2011
    Last edited: Jan 13, 2011
  6. Clint Neff

    Clint Neff Well-Known Member

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    Cory its great to see you on here. I remember those good old days as Toby was talking about working @ Kips shop. Hope you get something going on the drag racing side of things so you can stop driving around in circles looking for the finish line. Us drag racers drive straight for it! Shoot me a private message so we can exchange contact info. Dont get on facebook anymore so email or cell is best. We need to catch up.

    P.S. Toby you should of seen him in the strip joint when he went with us to pomona! You know which s..thole im talking about!
     
  7. cory

    cory New Member

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    Hey Clint,
    Man, I still think I'm hung over from that night!

    377 D/A,
    16 years ago I might have to agree with you, but with the technology that has come into cup racing in the last 10 years or so I think you might be a bit suprise at what a cup engine design can do. In regards to the acceleration rate, Nascar has rules on the weight of the bottom end and of the valve train, I think without this rules the acceleration rate would not be a problem. Also we have a 12:1 comp ratio limit. At 15:1 I think an R07 or a TRD would be one badass. We have to run a soild cam, unleaded fuel, max carb size of a 850, Bore limit, manifold limits, Cylinder head limits,and deck height limit. I love comp racing for that matter any drag racing. 19 years ago I thought going around in circles would suck, over the years I relize its just an engine and I love making as much HP as I can.
     
  8. C Tanksley

    C Tanksley New Member

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    Cory you said 2.75 per inch mabey . well that is 200 more hp than we have we ran 6.70 AT 1500 LBS add 100 lbs and 200 hp and you have a bad ass B/D . That leads me to belive a 6.40 at least, that is 84 under in B/D .
     
  9. Greg Schenck

    Greg Schenck Active Member

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    Rob, a cup motor (as is) sit it in a C/SM and it would be 50 over the index. Do the math.
     
  10. JJKay

    JJKay New Member

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    Charlie, 6.70 in C is pretty bad ass. Would love to see some fresh pipe around that drivetrain...
     
  11. Rob Harrison

    Rob Harrison Well-Known Member

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    Cory, good to have your input from the Cup side, so to speak. There is one side to the HP conversation, HP is not HP when it comes to drag-racing. If you were to find your way on to a Davenport inertia dyno, which measures HP by the rate of acceleration, 2 motors that both make 800 HP on a water brake, can vary as much as 100 HP on an inertia dyno.

    The new gen water brake software is a lot better than the 901 stuff, but a Cup motor has 1/2 an hour to rev up on the back straight, drag-race motor's have around 4 seconds on average.

    Years ago, Larry Morgan showed up at Davenport's with a motor that was 20 HP better in the trailer, than the one in the car, but was not as fast on the track. A few hours later showed the motor in the car was 20 better, a 40 HP difference in how it was measured.

    The 10,000 rpm Cup motor's, are impressive to say the least, drag-race motors could use a touch of that kind of reliability.
     
  12. cory

    cory New Member

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    Rob Harrison,

    How much of acceleration is base off of gearing? We are limited by Nascar for gearing. I would like to brake down the acceleration into segaments into a mile back straight, just have not done that yet. With the cup cars how you come off the corners makes so much of a difference in straight away speed. The fact that a comp car or a pro stock car can go from a dead stand still to a 6 sec to a 7 sec pass is cool. Has anyone here tried a chassis dnyo with there comp car? We chassis dnyo are cup cars ever week. I know we give up some hp for reliability, but we have to finish race.

    C Tanksley,

    Right now cup engines are making 2.478 hp per cubic inch.

    Guys I really like having this type of comparison between drag racing and nascar. Just to give you a heads up, this is what happens to a old rocker design after 1200 miles
    [​IMG].

    We now run steel rokers with no adjusters.
     
  13. C Tanksley

    C Tanksley New Member

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    The only time i saw a rocker broke like that was when a valve hit the piston first .It was not in our motor we run Patterson motors we never broke any rockers in 7 years . I am not going to say how high we turn our motor on a killer run . We have a driver that can hear everthing he will hit the kill switch at the least thing during a run .He has been driving dragerst fo 15 years we use to build our own stuff we had to be carefull a lot of old parts You learn to drive with your finger on the kill switch its called broke dick comp racing .
     
  14. Tony Pontillo

    Tony Pontillo Member

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    I run my B/DA dragster on our Mustang Dyno all the time. I use it to load the dragster for tuning. It works good for testing the trans and everything else before traveling long distance to race. Our dyno has a full size tree to make 1/4 mile runs. This works good for determing shift points and making sure we have the right stall. Our dragster makes about 125 hp less on the chassis dyno than on the engine dyno. not to mention it is just cool to stir up the neighbor hood right in the middle of town. For example we spent a day playing with rotating weight on the rear tires, brakes ect. its amazing the differance when you take 15lbs of rotating weight off!!
     
  15. Rob Harrison

    Rob Harrison Well-Known Member

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    Cory (your last name),

    None of acceleration (rate) is based on gearing, that variable has to be removed to assess accel rate. In the case of the inertia measuring method, the motor is hooked to a 700 lb flywheel, period, a dyno pull takes 2 1/2 seconds, HP is measured by the rate of acceleration, written into the software. A water brake "releases' the motor, so it has more time to get happy. As a small comparison (inertia vs. water)to the HP seen by a water brake, using 300 rpm per second vs. 600 rpm per sec. the HP seen is usually higher at the slower rate of release, simply because it has more time to sort itself out.

    Interestingly, we made some feeble attempt to tie our car down to a chassis dyno, it was a nightmare, and the rate that the motor grabbed rpm was the problem, trying to do a burnout on the rollers and jumping all over the place. If you would be able to get some grip and "roll" on the throttle, which would be useless data, the chassis dyno could compare how a 17 to 1 Comp motor makes power or more importantly, the rate of HP gain per 200 rpm. Dyno operators have a lot of respect for Comp motors and how to adjust the absorber to "keep up" with a Comp motor's appetite for building HP at an alarming rate. Put a flat HP curve motor on the dyno and the operator has a much easier job.

    A Comp motor doesn't need 1200 miles to fail a rocker arm, with 500 lbs. on the seat, and 1250 open, they can bust on start up. Not a common occurrence, but can happen at any time, usually when you need it least.
     
  16. TobyG

    TobyG New Member

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  17. cory

    cory New Member

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    Toby,

    That's an AVL dnyo the're running that on. Thoes are a eddie curent dnyo. For a cool 1.5 million we could have one!! Thats just for the dnyo then we need another 1 million for the room. Pretty much all the cup engines shop have at least one now a days. TRD has 3 of them out in California. That place out there is unreal. They can cut a valve job and cnc a head at the same time, when the head comes out of the machine you clean it a put it togther. I'll try and call you this weekend.
     
  18. 377 D/A

    377 D/A Member

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    amen to that again rob, it is really hard to dyno one of these dumb things. the hardest part of it is getting it controlled up high when they really start to jam. but if you load it down to hard, say so long to the ring lands. cory i can only deduece that you work at pro motor or triad but i don't think triad does chevy stuff anymore. am i right or did i miss something. over the years i would also guess that you realized that there is no money in drag racing which is why you go in circles. the only thing i don't like about what you do is the fact that if you take .004" of fuel out of one you don't know if it worked or not because there is at least a 50% chance that the car and motor and everything is going to end up in the stands on the next lap. other than that it is way cool i know alot of guys over there so i do understand but it is not so simple to do it as you may think. i very close friend of mine was the head tuner over at TRD for 4 years he said it is crazy out there. do you have any of the TRD chop sticks.
    ian
     
    #38 377 D/A, Jan 14, 2011
    Last edited: Jan 14, 2011
  19. C Tanksley

    C Tanksley New Member

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    So now i guess it safe to say that we won`t be seeing the round tracks motors setting any comp records anytime soon .
     
  20. tpsa101

    tpsa101 New Member

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    30k engines

    i am still laughing about patterson engines at 30k... we paid that in the mid 90's for something that would run .60 under... if you want to be competitive your in the 60-80 range depending on the class, ie; dry sump ,2 carbs, 30k wont even buy the parts....hahahahaha
     

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