That will work for a 4 cylinder that has 2 opposing cylinders to counteract the imbalance, but because of the 120° crank angle of a 6 cylinder crank, it takes 3 cylinders to counteract the imbalance because they never have another cylinder 180° away to oppose the weight difference. So you will need(2)sets of 3 R&P, not(3)sets of 2 R&P to do that.
Greetings . . .
The weather has warmed a bit and the shop isn't frosty - so I got back on the die grinder:
Assembly...Rod....Cap...Pin Bolt..Rod Bolts..Dipper...TOTAL
A..........467.4...202.5...21.9.......88.7.....16.0......796.2 (H)
B..........454.8...172.0...22.5.......88.8.....17.0......755.0 (L)
C..........460.4...221.6...22.0.......88.1.....15.5......797.0 (H)
D..........443.1...198.3...22.5.......87.6.....16.5......767.7 (L)
E..........455.9...186.4...22.0.......89.4.....17.0......770.2 (M)
F..........464.1...185.0...21.9.......88.7.....16.5......776.1 (M)
Average..457.6...194.3...22.1.......88.6.....16.4......777.0 grams
Max Var....24.3....49.6.....0.6........1.8.............. 42.0 grams
Ave Var..5.310%...25.5%...2.711%....2.033%.............5.405%
Abs Var..5.484%...28.8%...2.740%....2.055%.............5.563%
The dipper turns out to be another variable . . .
Getting rid of parting lines and polishing things up reduced the variabilty quite a bit. I also focused on the shoulders of the bearing caps.
They vary quite a bit from cap to cap (thickness and in how far they extend down into the oil trough). The heavier caps definitely carry more weight here. So I can take another pass to further reduce variability.
The Scott's point I am working them in pairs 2xH, 2xM and 2xL but I am trying to get two sets of H, M and L assemblies that are about equal in weight:
Cylinder
..1.. H...796.2 |
..2.. M...770.2 |
..3.. L...767.7 -> 2334.1 grams
..4.. L...755.0 -> 2328.1 grams
..5.. M...776.1 |
..6.. H...797.0 |
Matched together into sets of three - reveals only 6 grams difference front to back.
Leading to the question - which holes should the get the heaviest assemblies? The lightest?
regards,
stock49
