Engine ballance
03-20-2012, 05:12 PM
#2
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No but I'm building an LM7 using the crank, rods with Speed-Pro pistons I believe DNJ rings and ARP sportsman rod bolts and I have weight matched all of the piston, rod, rings and bolts assemblies to within 1/2 gram of 1 another but I'm working on the heads right now and probably will be a cpl more weeks until it's 2gether , but I'm pretty confident that it will run smooth ,,,,,,,the assemblies are closer 2 1 another then the factory assemblies were and a cpl machine shops I've talked 2 tell me that the bob weights on the crank are a little heavier than the factory assemblies so there is a little window of weight change because of the extra bob weight so as long as each assembly is within so much of each other then it will be balanced just fine ,,,,,,,,,,,better than factory in my case anyway .
BTW My pistons n rings r .030" oversized and the ARP bolts weigh more than factory rod bolts and each assembly is still within 3 or 4 grams of the factoy assemblies .
BTW My pistons n rings r .030" oversized and the ARP bolts weigh more than factory rod bolts and each assembly is still within 3 or 4 grams of the factoy assemblies .
03-20-2012, 06:00 PM
#3
Same question as OP...I've just installed a used LS1 crank into my existing engine.
Is each crank balanced independently, or is the crank balanced in conjunction with it's factory rotating assy?
Years ago, stock SBC 350 pistons could differ in weight by many grams. This was also true of all of the other components.
Conversly, I found all of the components in my LS1 to be quite close....but not perfect.
Is each crank balanced independently, or is the crank balanced in conjunction with it's factory rotating assy?
Years ago, stock SBC 350 pistons could differ in weight by many grams. This was also true of all of the other components.
Conversly, I found all of the components in my LS1 to be quite close....but not perfect.
03-20-2012, 08:11 PM
#4
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I wouldn't chance it, if everything is already out just have it balanced for piece of mind if nothing else or you'll be kicking yourself in the *** when something does go wrong!
03-21-2012, 02:03 AM
#5
FWIW, I used my factory LQ4 crank and used a set of LS2 rods and pistons and had it all balanced. They had to grind/drill the crank and took some material off of 1 or 2 of the rods to get it all balanced (I can't recall seeing anything being done to the pistons).
03-22-2012, 09:48 AM
#7
As posted prev in your thread, I'm in the middle of doing what you are.
My GenIII engine is different than yours, but the crank balancing should be the same.
The manufacturing tolerances are very close in these engines...very different from decades ago, when similar parts had very different weights.
So, after getting this answer, I'm gonna go with just putting it together...
https://ls1tech.com/forums/generatio...-balanced.html
My GenIII engine is different than yours, but the crank balancing should be the same.
The manufacturing tolerances are very close in these engines...very different from decades ago, when similar parts had very different weights.
So, after getting this answer, I'm gonna go with just putting it together...
https://ls1tech.com/forums/generatio...-balanced.html
