how much is to much when ballancing

[150aintenuff]

when ballancing rods, I have 2 of the 818141 top guideds thT ARE 373, 375G , 3 THAT ARE 363G AND 1 THAT IS 348G STOCK, after cleaning up the first (lightest rod) its finished weight is 320-321 g. is it safe to take the 375G rods that far down or should I dig in my pile for 2 lighter good rods closer to the others.. I really dont want to get the heavier rods all done up and find they are still 15G heavy.. should I ditch the heavier 2 or has anyone safely dropped the weight that much...

[Fl Boy in ILL]

A lot of times we will weight match rod-piston and wrist pin, you will find the pistons will be different just like you are finding with your rods, you can take your lightest rod with your heaviest piston and end up pretty close without having to do a lot of reduction just on the rod and save yourself some time and effort. We try to get the whole piston, rod , wrist pen assembly within 1 gram. Good luck, hope this helps

Rick

[150aintenuff]

i dont like doing that because of the WHAT IF factor on the fact that if this ever has to get redone any time in the future that everything is already ballanced to each component.. so that way all the pistons are the same, rods are the same, ect... and within .5 gram across the whole assembly...

[150aintenuff]

so far the 1 finished rod is at 321 grams, 4 ground but not finished rods are at 325g and it will take about 2-5 g more to finish so they will be Ok, its the last rod that is concerning me, started weight was 379G, roughed in weight is 346.5G

if i mix nd match for ballence it leaves more work later on future rebuilds because i would have to mix and match again versus grinding one new piston/ wrist pin to match the existing setup

[pirogue]

The Rod to the left came out my drag motor when i bought it and will not be going back in.





Here is a pic from boat works website.

[mrcrsr]

also, on the rod, on the opposite side of the casting number is a 2 digit number that is SOMEWHAT reflective of the weight, you are supposed to be either pos/negative 1 digit between the set of 6 to start with, as for weight matching each assy, i do quite a few motors, and the pistons are usually within 2 grams of each other, so you are not going to be able to get to where you need to be by weight matching, so either get another rod that is closer or start removing material!!!

[manateemauler]

are you going to spin balance the crank with bobweights?
You have to have each end of the rod weight the same
I.E. big end small end- you may want to contact someone in person who does
crank balancing in your area. Don't rely on internet advice, you may be sorry.

[Jay Smith]

I do NOT take 41 series rods down from the 370 to 320 PERIOD you will then have an integerity issue some people may disagree , I could and can care less . Throw the VERY light OUT of the equation and find another rod closer to your set.. We do these rods everyday ..

Most ALL forged pistons that come in a set are with 1 to 2 grams of being perfectly the same weight in grams wrist pins ARE also within 1 gram in a set of being the same weight in grams..

Good luck,
Jay

[150aintenuff]

thanks jay, one of the 370 G rods had ALOT of casting flash, and t came down to the rest when i roughed the rods in, the heaviest rod isnt even close so i will ditch it and pull another out of the pile,

[150aintenuff]

are you going to spin balance the crank with bobweights?
You have to have each end of the rod weight the same
I.E. big end small end- you may want to contact someone in person who does
crank balancing in your area. Don't rely on internet advice, you may be sorry.

yes the crank is getting reballenced, i had to do remove a bt of material that got dammaged off the counterweight when the motor threw a rod, so its getting done right now..

[150aintenuff]

ok heres how everything turned out, I know these are still heavy considering some people go down another 20 or so grams but the caps all match, as do the rods with a total without bolts weight of 321.5G adding bolts in brought total of 344=/-.5G so i am happy thanks everyone