Rods

Discussion in 'PSI Superchargers Tech Questions' started by dstettner, Sep 22, 2012.

  1. dstettner

    dstettner New Member

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    What would the problems Be that can arise from from running a steel oliver rod thats 7.500 long in place of my grps?? In a top dragster blown alcohol big chief motor . I just would like to get more than 50 passes out of the motor before having to put rods in it 871 high helix makes 1500 to 1800 depends on pulley set up ????? I need to bracket race it or can the grps go more than that ?? i run it to 8000 rpm through the end
     
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  2. underby6

    underby6 Active Member

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    That'd be a big no-no, with our 8-71 setup we changed rods at 20 runs. I ran R&R with that setup, no problems. With our TAD we've used R&R, GRP, and MGP; I truly believe the MGP is the best rod out there. You could look at a forged rod from BME, I've heard mixed reviews on running a forged rod in a supercharged motor. With any rod there is no set amount of time/passes; you should take them out after a weekend or two and measure the pin end and rod end with a dial bore gauge. The gauge will not lie to you, you may have 7 that are great and one that's ready to kick. The cost of keeping fresh rods in it is exponentially less than repairing equipment when it kicks the bones out. I would say there isn't a rod out there that'd be recommended by anyone with a functioning frontal lobe to use to 50 runs with a blown car.

    Brandon Booher
    NHRA TAD #34
     
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  3. AFC357

    AFC357 New Member

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    I agree w/Brandon here...can't say anything bad about R&R or GRP...but have run MGP and LOVE them...and NO...ya can't run them forever...we put 20 to 25 max then on the souvenier stand they go! Now Brooks.....don't get me going on that junk! They are gone now...imagine that! Sorry, I just say it the way it is (or was):cool:
     
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  4. dstettner

    dstettner New Member

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    Thanks guys im new to the blown deal i had heard of a couple top dragster running steel rods and were just changing bolts on freshen up ill stick to my routine but i guess ill change them out at 20 or 25 runs might switch to the mgp rods though keep hearing good stuff about them grps have been great too had brooks junk in one of my big inch naturally aspirated motors and kicked the rods out at 13 passes needless to say i switched to grp i talked to grp and they told me 50 runs should be safe but i dont want to be buying new donovan blocks every year once again thanks
     
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  5. john348

    john348 Top Alcohol

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    We have run brooks, BME, Howard’s, C&A over the years and have been using MGP’s for the last 8 years now, they are best rod out there bar none, I have never broke one yet
    But you have to maintain your deal; I still can't let myself put the amount of runs on them that Michael tells me to yet.
    Then again this is just my opinion...
    Like good judgment comes from experience, and a lotta that comes from bad judgment
     
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  6. underby6

    underby6 Active Member

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    If GRP told you that I'd ask them who is the car that's similar to yours running them to 50? I'd talk to that person and hear it straight from them. I'm not saying it isn't true, but maybe there's one car who did it once etc. etc.. MGP tells me 25 runs and they're still good, even shifting at 10,500 or higher. I am glad he is that confident in his product, I'm just not that confident I could afford to double check him. That said I took a set out last winter that had 12 runs on them and not a single one was good. I wasn't beating the motor, just something you have to check. We had a NA car we ran (dragster), we used Carillo Steel Rods in it; I'd say you could run them forever but a blown deal is a whole different beast. The best advice I've ever been giving regarding cyclical wear on parts is "don't fall in love with racecar parts".

    Brandon Booher
    NHRA TAD #34
     
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  7. Dale Finch

    Dale Finch Member

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    This is concern of mine too. I am helping a good friend get started with his high 6 second bracket car. We have never run rods more than 25 runs but hey thats alcohol racing. A little different with these cars because they can make so many runs. I have heard some folks have put 75 runs on rods but most about 40-50.
    thanks
    Dale
     
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  8. moparchris440

    moparchris440 Member

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    526 BAE 18-71 M5 45 lbs in a 3300 lbs Outlaw deal, running 1/4 mile only running it to 8900-9000 rpm's, 50 plus passes 3 yrs in a row never a problem GRP's I think rpm's wear out rods, keeping it under 9000 and with a 2 speed and a 1.40 first gear its not running peak rpm during the run to long.
     
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    Last edited: Sep 23, 2012
  9. Dale Finch

    Dale Finch Member

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    Hey MoparChris. Do you just run the rods or do you send them back to Brian and have them made round again or just run them?
     
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  10. moparchris440

    moparchris440 Member

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    I give them away to the kids, I buy new ones every season.
     
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  11. secondwindracing

    secondwindracing top alcohol

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    rods are like concrete...i if it is going to crack..it is when it going to crack
     
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  12. dstettner

    dstettner New Member

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    Hey mopar chris thanks for the info good to know someone else runs em to 50 passes like myself mabe i wont change em at 20 then i only run it to 8000 soon to change when i put a 3.90 gear in it would have to fly to see 8000 rpm
     
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  13. overkill69

    overkill69 Member

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    8000 rpm is easy. Bill Doucet builds a bunch of Chevys with GRPs and they can go well over 50 runs with a screw blower.
    I wouldn't be surprised if they go 100 laps on your combo.
    Like somebody else said, big difference between 8000 and 10000 rpm.
     
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  14. dstettner

    dstettner New Member

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    Great to know thanks for the info
     
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  15. Blown5402

    Blown5402 Member

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    50 Runs on Rods

    We have run one of the name brand rods you are talking about here and we run 45 to 55 passes a season on the 1/8 mile only; and that makes a big difference I think too. We shift at 7600 and go through the lights at 7600rpm. We run blown alcohol at about 46#s of boost with a Kobelco Superman and run pretty fat and low timing. That gives us 3.80s with a powerglide and never any bearing problems either. It just depends on how hard you run your parts and it is very hard for a rod manuafacturer to tell a person 25 to 30runs, and he still blows up his parts, due to very extreme conditions. Just like some above said, do not fall in love with your parts, and change them out when they need changing and save big money! THANKS!
     
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