CAT 3408 V8 crank balance

[Dave Koehler]

Another first for me.
I got an inquiry to balance a Cat 3408 V8.
This is a split journal crank.
I think I have the necessary tooling to do this.
Question:
Anyone have any idea what the balance factor might be for a split journal V8 or a cat version in particular.

[jred]

bored a couple of 3408s years ago i thought that the crank was a straight pin crank and not a split pin but could be wrong,, i talked to Gary at ABS about some balancing split pin cranks and he said that as most were 36.6 percent that he recommend 50 percent.. when in doubt weight up the weight and set for the smaller percentage and then spin crank and see if its too far off if it is weight up and set up for the bigger percentage and check again.. also because of the weight of the crankshaft the tolerance is greater some thing like 10/15 grams at rpm,,, I have some info in some older books from Hines and Bal-tech that might tell I'll look in the morning

[Scotty]

A 3408 series is a wet liner engine, you might be thinking of the smaller 3208 series. The 3408 is a split crankpin and i think its a 60 deg v.? Definitly not 90 deg.There is also a couple of different counterweight cranks in this series engine aswell. Warren turner might be able to give you a percentage ? Worth a call or email.

[Dave Koehler]

Yeah, I figured if push comes to shove that I would have to reverse engineer it.
It is definitely a 3408, 60 degree, split pin crank.

[Jagdpanzer]

Work for Cat when the 3408 was introduced and it is definitely a split rod journal crank. Cat’s thinking was this would be effective at reducing vibrations inherent with 60 degree V angle V8 engine. This was a multi purpose engine used in earthmoving equipment, marine, power generators, industrial, and class 8 on highway trucks. It was the trucks that drove the 60 degree V angle decision.
Made good power for it’s time however, it was not one of Cat’s best engine designs. They never could solve the vibration headaches which the 3406 inline 6 and 3412 V12 versions of this engine family did not experience.

[modok]

Good question!
I don't know......

[jred]

boy i guess i got that 1 wrong,, thats what happens when you get older..