Icon IC 743 piston weight incorrect

pishta said

I asked him in a comment about it and he replied the same way, on a 180 crank in a 4 banger, they self balance if the piston packs are neutral (1+4=2+3). a 120 crank (straight 6) and a 90 crank (V8) do require a little more math. Ill put this out to anyone trying to do rods at home: nm9stheham and I found repeatablilty the hardest part in building rod jigs. both of us had failures and successes but I for one never found a rock solid platform (or maybe more so a digital scale) that would give me 3 for 3 +- .1 or even .2g resolution. I accepted .3 at that and moved on. We all know Mopar didnt go this far at the factory so meh.....made me feel better trying and its a heck of a lot closer than factory specs.

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As I understand it (per my local machinist of 40+ years), an inline 6 is like an inline 4.... no reciprocating weight is needed. A V6 is like a V8 where you have to separate out the reciprocating weight and use a factor of 35% for the V6 versus 50% for a V8.

Yes, separating the reciprocating from rotation weight in the rods is the challenge. It took a while to get my jig set up to where I have high confidence in it.... so the total rod weight was consistently within 2 grams of the reciprocating + rotating weights. Even Smokey Y. says that is hard...

But, the way the OP is planning (I think) is to take the same weight off one end, then the same weight off the other end. So he won't be distorting the weight difference between the 2 ends.