More Aluminum Rod Questions

Discussion in 'PSI Superchargers Tech Questions' started by Maynard, Aug 23, 2004.

  1. Maynard

    Maynard none

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    Would I be better off running steel rods in a blown injected hemi that was only making about 1300-1500 hp? I want to run that C.I.F.C.A. 7.50 e.t. stuff. I wouldn't be using a whole bunch of ignition lead so I shouldn't get into a bunch of detonation.
     
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  2. Mike Canter

    Mike Canter Top Dragster
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    That is a hard question because I would not want to be responsible for telling you the wrong thing and blowing your motor and because of that I will tell you this. First I do not know of a steel rod that can take the 1500 hp. If you did find one then it would be real heavy and would require a lot of heavy metal in the crank to balance it. The inertia of a crank that had the heavy rods and the heavy counter weights would always be a problem. The other great thing about aluminum rods is that they cushion the blows to the crank and make both the cranks the rods and the bearings last longer. Also with an motor like that you should be able to get 60+ runs out of a set of aluminum rods. If it was my motor I would use aluminum rods.
     
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  3. altered boy

    altered boy Outlaw Altered

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    ok... i may be off base, dunno. but i don't think the steel rod would end up being huge and heavy. just the opposite... look at how big a aluminum rod is in comparison to a steel rod. they end up weighing about the same because the aluminum is a weaker metal and requires more material to handle the abuse. if the steel rod is that 'weak' then how are the off shore boat guys able to make 1200+HP spinning 14-71 blowers for hours and not pitch them? granted the rpm's are little less... but the abuse is pretty brutal cause those guys are constantly in/out of the throttle. a buddy of mine throttles an offshore boat... and from the video i have seen it would be similar to a drag car running an hour long race and constantly spinning the tires and winging the motor. i don't think there is any way you could do that with an aluminum rod. i have heard the theory regarding aluminum rods offering a 'cushion' on the bottom end which give the tune up in an alcohol set up a little break. i've asked the same question regarding the steel vs aluminum and those are the answers i've gotten.

    bottom line maynard... at the moment i'm running aluminum rods in my blower motor. i REALLY want to try the steel rod experiment... but at the moment my wallet is not that brave. i did hear a rumor that there might be a competitive ta/fc team running steel rods... don't know if i believe it or not
     
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  4. cnitrofumes

    cnitrofumes Member

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    Here's my story... ran a steel rod blown alch. BBC in an altered for years. They were Crower billet rods. Crank was a FACTORY 3.75 stroke steel unit which had been cryo frozen and nitrided. Block was a filled factory cast iron 4 bolt piece and heads were cast iron rect. port 990 castings. It had a std helix 871 and made probably 1150hp on a good day. The car went 7.30 @ 190. We ran it two seasons on the same bearings !!!! Just never looked bad ! Granted this was no maxium effort blower motor but sometimes I wish I had it back. It's still going in a low buck promod out in Ohio.
     
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  5. Maynard

    Maynard none

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    Lol Thanks Mike, I really wouldn't hold ya responsible, there's plenty of people right here I can blame....Actually, I am just "exploring" outloud and wondering if someone had already been there, done that reliably. I just cant help but figure without a bunch of lead I wouldn't have to worry much about hammerin it with detonation (all other things being good that is) Thus my lack of concern with cushion. But thanks for the input.

    Thank you Altered Boy. I also expect to be able to keep the RPM range rather reasonable with this rather docile motor, maybe 8500-9000 tops.

    LOL CNITRO, I've had the same luck with them chevs. I just always used good rods and heads and left the crank and everything else up to the engineers at GM for the most part. Its kinda nice to throw $200.00 at it every April to get ready for the season. To winterize, simply knock her outta gear and place a boulder on the throttle to empty the fuel tank.

    Thanks for the help guys, I think I will order a set of them Crowers and see what happens. I'll keep ya posted.

    -Maynard
     
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  6. suthie

    suthie Jr. Dragster

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    Here are some rod weights from various manufacturers catalogs using a BBC 6.385 rod as an example. The weight for the strongest rod available from the catalog is shown.
    Steel billet
    *Crower-870g.(HP range 1000)
    Oliver-855g.
    Aluminum
    Manley-670g.
    R&R-663g.
    C&A-665g.

    *Kerry Novak in the crank/rod tech. dept. @ Crower is well informed,up to date and won't B.S. ya! You can try to call but most times its better to fax and ask him to call YOU.
     
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  7. Danny Humphreys

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    The blown offshore guys do it w/ crower and oliver rods with no problems. ask you rquestion here. OFFSHORE FORUM
     
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  8. Maynard

    Maynard none

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    Thanks Danny
     
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