GasGas and the future of 2-strokes

[Berkyboy]

GMP -- the ignition side bearing is a caged round ball bearing not a roller bearing.



I know for a fact that the new crankbearings are not ceramic.

Boni (GasGas's head 2-stroke mechanic/engineer) could not tell me what kind of bearing it was specifically.

He was very protective of saying exactly what it was. When I guessed ceramic he only laughed, saying they definately were not ceramic.

He did say that the bearing will have a new GasGas part number and will work in the most current engine cases for the 200 / 250 and 300s.

He did ask for a set of ceramic bearings to test and was very impressed with the quality of the NTN (Japanese made) based bearings we provided. He said a few years ago they tested some SKS (Slovakia made) based ceramics bearings that they felt had very little improvement over what they were already using.

More specifically he wanted to test our NTN based ceramic bearings in a 125 as he felt that engine would be easier to test for longevity and increased horsepower.

[GMP]

Very interesting. Maybe I can dig up some info on what it could be. Did he say what are they doing about the big end rod bearing?

[dcg141]

Forgive my ignorance if I am wrong here but I have lead to believe that is not total loss oiling that makes 2 strokes not meet emissions but the fact that a 2 cycle engine cannot shut off the exhaust port before raw fuel starts to enter the cylinder. Its the raw fuel that escapes thru the exhaust port that is throwing the emissions off. The way to get around that would be direct injection that can wait for the piston to shut off the exhaust port before sending any fuel to the cylinder. The reason I bring this up is that Stihl and Shindawa have 4 cycle trimmers that use total loss oiling IE premix and meet tier 3 emissions for small engines. Stihl says that oil can be formuated to burn cleanly enough to pass...but you have to have a closed exhaust before fuel is introduced to the combustion chamber. The same technology used in direct injection diesel engines can be used for 2 cycle also. Some car manufactuers are said to be experiminting with DI 2 cycles for fuel effiecncy. An Civic sized car with a DI 2 cycle could get up to 100 MPG.

[topari]

dcg141,
on many of the technical forums I contribute we award 0-10 points for the worthiness or quality of contributions. I would give you 10 points. Your article was a good read. Thanks.