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Old 07-31-2005, 12:32 PM   #1
Chugger
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Will a 6in rod work with a stock stroke 350?

Hello,
I found a great deal on a set of eagle 6in rods but i dont want a stroker i already have a forged 350 crank and a stock 350 block. What will i need to make these 6in rods work in this block, different pistons, machine work or notching the block?
let em know asap
thanks
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Old 07-31-2005, 03:51 PM   #2
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the crank makes the bigger stroke, not the rods... the displacemt of you motor will actually be the same, well that is until your pistons try to knock your head out through the hood ... i would let the 6 inch rods go to someone else and spend the $$$$ on pther speed parts to make that 350 scream, and built right you can out RPM and fly by a 383... just my 2 cents...
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Old 07-31-2005, 04:02 PM   #3
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yes, you can put 6 inch rods in a 350. you need to make sure that you buy 350 pistons for a 6" rod. this will give you more torque over a 350 that is exactly the same with stock rods, but it also increases your rotating mass, so your rpm max will drop a little bit. other than the different pistons, you can slap those 6" rods right in.
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Old 07-31-2005, 04:05 PM   #4
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yeah genIII is right about the different pistons you can use... just had to chime back in ...
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Old 07-31-2005, 06:03 PM   #5
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I wouldn't hold my breath waitning to "feel" a performance difference...but from a strength/reliability stand-point, you can't go wrong with this. The longer rods are easier on the cylinder walls, bearings and even wrist pins. Nothing wrong with the 5.7s, but if you can get a "deal" that won't cost much more than rebuilding the stockers, why not?
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Old 07-31-2005, 08:27 PM   #6
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I don't know squat about rod lengths & stuff. But I do know about " deals " . I love deals, but a lot of the deals I've got over the years often meant more frustration and sometimes more money in the long run for something that wasn't exactly what I wanted. A wise man once said " A bargain is something you don't need at a price you can't refuse". Good luck with your motor.
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Old 07-31-2005, 09:36 PM   #7
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These are two sites I found on searching rod length on the net, good info



http://www.victorylibrary.com/mopar/rod-tech-c.htm

http://www.truckpulls.com/Tech%20Fil...20Prepping.htm
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Old 07-31-2005, 09:50 PM   #8
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Quote:
Originally Posted by GenIIIShorty
yes, you can put 6 inch rods in a 350. you need to make sure that you buy 350 pistons for a 6" rod. this will give you more torque over a 350 that is exactly the same with stock rods, but it also increases your rotating mass, so your rpm max will drop a little bit. other than the different pistons, you can slap those 6" rods right in.
how does it increase the rotating mass? Sure the rod may weigh a few grams more..but the piston for a 6" rod is a lot lighter...lighter in the right end of the stroke

oh for a deal..check this out
http://www.cnc-motorsports.com/product.asp?ProdID=4187
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Old 08-01-2005, 02:31 PM   #9
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i did some more research and found a set of 5.7in h-beams for fairly cheap. Gonna try to build the motor for spray. I spun 2 rod bearings and 1 main the pther day. Gonna get a forged crank, h-beam rods and some forged pistons. Not sure on the compression ratio yet thinkin high 9's to mid 10's any info on that would be greatful?
Also it has a 125 shot now it will prob end up with a 200-250 shot not sure yet.
gonna get a set of aluminum double humps or the new cast heads from jegs or summit not really sure on the heads i might even go with vortec heads.
any info will be greatly appreciated
thanks
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Old 08-01-2005, 02:52 PM   #10
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Longer connecting rods provide for a greater moment arm which results in greater tourqe. There is not a huge difference in mass (and that will probably be compensated for by the new pistons anyway) but like any lever system, you can use a short moment arm to gain velocity or a long moment arm to gain tourque. A connecting rod may not look much like a lever but that is exactly what it (in combination with the crank journel) is.

There is a set amount of energy released in any given engine. Making a mechanical change such as this does not change the net energy release, it changes how it is transfered from the reciprocating action to the rotational action.
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Old 08-01-2005, 11:11 PM   #11
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Long rods can drastically lower rotating mass. Generally the shorter the compressed height of the piston the lighter the piston will be. Since the piston is out at the end of the rod is is the most effective place to lose rotating weight. Think about a rod/piston like a hammer, a light handle with a heavy head takes a lot of work to swing but is very destructive. A slightly heavier handle with a lighter head is a lot easier to swing and is less destructive. In an engine, less destructive is GOOD.
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Old 08-02-2005, 02:37 AM   #12
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You will have to get the block notched. Most machine shops will have a template so they don't have to notched to fit.
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Old 08-02-2005, 09:43 AM   #13
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Block should not have to be notched just for longer rods. If stroking, then yes, but you are using 3.48 stroke.
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Old 08-02-2005, 09:56 AM   #14
Chugger
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Just using the stock stroke but am getting a forged crank. I am looking at sppd pro forged pistons but cant decide on the comp to get? Again this motor will be bottle fed on the track and maybe every now and then on the street as well just depends on the victim. Also i am torn to decide what bearings i want clevite or sealed power i have heard great things about both but need someone with firsthand experience with it
thanks
chris
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Old 08-02-2005, 10:32 AM   #15
ed455
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On a sbc 400 some notching needs to happen when using H beam rods, but for the 3.48 stroke, I can't imagine it would be necessary.
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Old 08-02-2005, 10:18 PM   #16
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My Malibu block is notched. It's stock stroke with the Eagle h-beam 6 inch. With the longer rod, the side does come closer to the block. The machine shop used the template and spent 5 minutes to take care of any posibilities of the rod coming too close. I guess to be on the safe side.
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