stroker rod and piston selection opinions

Discussion in 'High Performance Modifications' started by LT1 WS6, Feb 25, 2016.

  1. LT1 WS6

    LT1 WS6 Veteran Member

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    I'm getting close to putting together my LT1 stroker engine. Just going with a simple 383 topped with Advanced Induction 200cc LT1 heads along with their 232/242 108 cam. Lift is 0.615 on this cam. I already have a Scat forged crank. I'm looking at rods and pistons now and just wanted some input from those that have more experience with this in case I've overlooked something or am missing anything. The car is just a street car. I won't be drag racing it. I'll have fun with it from time to time of course and may even autocross it or due an HPDE event. Point being, I'm not trying to set the world on fire with my combination. I just want a solid reliable build.

    Since I need rods and pistons and am an engineer, I've tried to put some thought into my choices. Or, I'm just over thinking this which is typical of engineers.

    I'm looking at Mahle forged pistons for a stroker running 6in rods. They have been recommended to me as being a quality piston with good sealing and low friction. They are listed as being 406g too which is lighter than the 5.7in rod pistons from Mahle.

    For rods, I'm torn between H or I beam. Scat's procomp I beam rods are 605g, $300, and rated for the power I expect to make. Scat also has H beam QLS rods that are 569g but $550 for the set. I'm not trying to be cheap with my build, or get crazy expensive, but my understanding is H beam rods can be more difficult to fit the block and clear the cam. Is this correct? Are they worth it?

    Eagle also has H beam rods but they are much heavier than the QLS Scat rods and only a little cheaper. Are Eagle rods that much better than Scat's?

    All the rods I'm looking at are 6in, forged, and clearanced for a stroker. I see no reason to go with 5.7in rods due to cost and the components being heavier. I realize I might not being going with the lightest components out there but I figure I might as well try to put some thought into my selections.

    Opinions? Suggestions? Anything you think is relevant is welcome.

    Not sure if it matters but the block has had steel 4 bolt straight caps installed with ARP studs. I intend or hope to run the stock windage tray and oil pan.

    Thanks
     
    Last edited: Feb 25, 2016
  2. Damon

    Damon Veteran Member

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    Can't say that H-beams are any more or less difficult to fit in a stroker engine. The place that clearance is an issue is around the rod bolts. The head of the rod bolt is what MIGHT interfere with the cam and the rod nut is what MIGHT interfere with the oil pan rail. The area where the rod beam lives is pretty wide open real estate.

    They make rods specifically for stroker applications now (though I've never used them). Should be easier to fit them in than a stock-type rod.
     
  3. LT1 WS6

    LT1 WS6 Veteran Member

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    Thanks Damon. You bring up a good point that I left out. The rods I'm looking at are all stated as being clearanced for a stroker application.
     
  4. 73 Z

    73 Z Veteran Member Gold Member

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    There's no cure for over thinking, but I went with 5.7 rods due to the P-pin and ring location. Don't know about others but the scat 5.7 I rods clear with no mods. Check all interference with a paper clip 0.060 should be fine.
     
  5. 77 cruiser

    77 cruiser Veteran Member

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    Scat Procomp rods have more clearance everywhere than a stock 400 rod & are plenty strong to 600+ hp.
     
  6. G72Zed

    G72Zed Veteran Member

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    Thumbs up for Scat 6.0 I or H beams designed for stroker cranks, better choice than Eagle.

    Also, pending part #, Mahle has nice rings packs and oil ring placement so no need for oil rail supports, that's a key indicator.
     
  7. Lowend

    Lowend Administrator. .a car, a man, a maraca. Staff Member Lifetime Gold Member

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    H-Beam rods being a good thing are one of the great falsehoods of the automotive world.
    H-Beams are weaker, and heavier than their I-Beam equivlents

    Note a Formula 1 Rod - keep in mind these go to 20,000RPM for hours at a time

    [​IMG]

    My suggestion:
    6" I-Beam rods. If you're on a budget the Scat units are fine (I used them in my own car), if you have a little more to spend, Crower's are awesome.

    Piston-Wise, on a street car as long as they are forged you are probably ok. It's hard to beat JE/SRP for the value.
    I highly recommend having the piston faces coated to improve heat reflection properties
     
  8. LT1 WS6

    LT1 WS6 Veteran Member

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    This was something that also attracted me to the Mahle pistons though I've also been told it's not that big of a concern for my application.

    These are these pistons I'm considering. Just need to verify they'll work

    http://www.summitracing.com/parts/mle-sbc125030f05/overview/


    Lowend, who does piston coating and what does it typically cost?

    Thanks everyone
     
    Last edited: Feb 26, 2016
  9. Rust eater

    Rust eater Veteran Member

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    Hi. Hope I can add something to this for you. First, those pistons are .030 383 for the 6 inch rod. So they will word for you. Second Rod clearances, 6 inch rods do create some issues with clearance at the cam and at the block. You should also verify that your crank counterweights are cut for a 5.7 inch rod piston combo. Scat forged come both ways. If you bought a 6 inch rod crank A 5.7 rod piston wont clear in the skirt area. The block part is easy to fix in most cases. Some material will need to be removed from the pan rails. Sometimes a notched pan is needed. You wont be able to determine how much until you assemble the rotating parts. The area around the cam is the issue especially with H-beams. They are usually thicker at the big end and will often times contact the lobes on larger lift cams. I have even had H beam 6 inch rods contact the bottom of the bores on occasion, depending on how the block was cast. I beams will be easier to work with. And handle the kind of power you should be seeing. 6 in Vs. 5.7, 6 inch rods move the piston pin up into the oil control ring land and ring sets should include a set of ring stabilizers. This is not an issue with 5.7 rods as the pin does not enter the ring land area. Pistons for 6 inch rods have much shorter skirts and do affect piston stability in the bore increasing wear. This wont be a problem if it's not your daily driver, but being forged they will naturally be looser in the bore than cast or hyper. So expect some noise from them until the engine warms up. You have put a lot of thought into this and that will pay dividends in the end. In the end on a limited use motor rod choice is builder/owner preference. Is the extra work to make them fit worth the extra torque?
     
  10. Rust eater

    Rust eater Veteran Member

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    Look at the big end of that rod....And the overall length. Short rods can really take revs. Short stroke and compact rod =20,000 rpm
     

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