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My comments from another forum;
I have some internal parts I have found at sites that deal in used NASCAR parts and the like, that I intend to use. I was hoping to limit the time the engine was apart by getting parts collected first . Ya dumb I know.
But I have lost faith in some of the info I mined with much effort from forums. Even when two or more claim the same thing. so Sunday I will take it all apart and check every thing my self. Every thing. And restart.
First is the block, after a hot tanking at my sons work it will come to mine so I can go over it with a CMM. (coordinate measuring machine), there is conflicting info about cylinder offsets. That I need to settle to my satisfaction! If both cyl. Are moved away from the cam then the engine is a 61 degree V6 and should be an odd fire engine. 121, 119, 121, 119. Or are the crank throws offset to correct it like a Buick but much less? The crank grinder will need to know and so will I.
However I have seen no mention of odd fire or crank offsets(indexing),
Anyone???
I see “the new 99mm (3.9in) bore required offsetting the bores by 1.5mm (0.1in) away from the engine center line” repeated often. (1.5mm =.0590 in)
The bores are at 60 degrees to each other. When the pistons are at tdc the rod angel would be more than 60 degrees because of cylinders outward movement.
I have never seen any mention of how they compensate for the change in the stock engine.
Some claim the wrist pin is offset “like in the LS motors”. In the LS one bank of pistons have the pin moved 1mm away from center line and the other bank 1mm towards the center line. I have a set. This will increase the difference in geometry from bank to bank when used in the LZ9 if the 1.5 outward is correct.
Should I be using 6 LS pistons all from the same side and turn 3 backwards???
This would reduce pin offsets to .5mm (.0197in) relative to the crank if the crank is ground at 120 degrees. If so I need to throw out 5 of my new Wiseco pistons and buy 3 more of the same side for 6 all the same! F***! F***!! F***!!!
From other;
“If you are using offset wrist pin pistons, then you do not want the offset to both toward or away from center on both banks. You want the offset to be toward the major thrust wall of the cylinder (or opposite the crank rotation direction)”
You're 100% exactly right. For an LS and all motors I'm aware of except for LZ9/LZ4.
These engines (probably) have the cylinders moved outward. Opposite directions. Odds towards the major thrust side. Evens toward the minor thrust side.
Using the ls piston in our cyl. #1 and you add the 1mm of the piston to the 1.5mm of the block! (2.5mm = .0984in outward)
Using the ls piston in our cyl. #2 and you subtract 1mm for the piston from the 1.5mm of the block. (.5mm = .0197in outward)
It maybe OK up to 5 or 6000 rpm. But at 7, 8000 or more, umm... not good.
Its the odd numbered bank that is bugging me.
This all relates to the cam as well!
I have some internal parts I have found at sites that deal in used NASCAR parts and the like, that I intend to use. I was hoping to limit the time the engine was apart by getting parts collected first . Ya dumb I know.
But I have lost faith in some of the info I mined with much effort from forums. Even when two or more claim the same thing. so Sunday I will take it all apart and check every thing my self. Every thing. And restart.
First is the block, after a hot tanking at my sons work it will come to mine so I can go over it with a CMM. (coordinate measuring machine), there is conflicting info about cylinder offsets. That I need to settle to my satisfaction! If both cyl. Are moved away from the cam then the engine is a 61 degree V6 and should be an odd fire engine. 121, 119, 121, 119. Or are the crank throws offset to correct it like a Buick but much less? The crank grinder will need to know and so will I.
However I have seen no mention of odd fire or crank offsets(indexing),
Anyone???
I see “the new 99mm (3.9in) bore required offsetting the bores by 1.5mm (0.1in) away from the engine center line” repeated often. (1.5mm =.0590 in)
The bores are at 60 degrees to each other. When the pistons are at tdc the rod angel would be more than 60 degrees because of cylinders outward movement.
I have never seen any mention of how they compensate for the change in the stock engine.
Some claim the wrist pin is offset “like in the LS motors”. In the LS one bank of pistons have the pin moved 1mm away from center line and the other bank 1mm towards the center line. I have a set. This will increase the difference in geometry from bank to bank when used in the LZ9 if the 1.5 outward is correct.
Should I be using 6 LS pistons all from the same side and turn 3 backwards???
This would reduce pin offsets to .5mm (.0197in) relative to the crank if the crank is ground at 120 degrees. If so I need to throw out 5 of my new Wiseco pistons and buy 3 more of the same side for 6 all the same! F***! F***!! F***!!!
From other;
“If you are using offset wrist pin pistons, then you do not want the offset to both toward or away from center on both banks. You want the offset to be toward the major thrust wall of the cylinder (or opposite the crank rotation direction)”
You're 100% exactly right. For an LS and all motors I'm aware of except for LZ9/LZ4.
These engines (probably) have the cylinders moved outward. Opposite directions. Odds towards the major thrust side. Evens toward the minor thrust side.
Using the ls piston in our cyl. #1 and you add the 1mm of the piston to the 1.5mm of the block! (2.5mm = .0984in outward)
Using the ls piston in our cyl. #2 and you subtract 1mm for the piston from the 1.5mm of the block. (.5mm = .0197in outward)
It maybe OK up to 5 or 6000 rpm. But at 7, 8000 or more, umm... not good.
Its the odd numbered bank that is bugging me.
This all relates to the cam as well!
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