NECR Geeps sound like...

Wasn't the only 4-cycle EMD ever used the "H Engine" (or something like that) that was supposed to replace the 710 and allow them to reach the 6000hp mark, and was used in the true SD90MACs?

octr202 wrote:Wasn't the only 4-cycle EMD ever used the "H Engine" (or something like that) that was supposed to replace the 710 and allow them to reach the 6000hp mark, and was used in the true SD90MACs?

Yes, that's what I was referring to when I wrote "with one exception -- the ill-fated SD90MAC-H." That locomotive used the 265H engine -- the only 4-cycle engine built by EMD. All other EMD locomotives, including those currently in production, use a 2-cycle design.

MEC407 wrote:

octr202 wrote:Wasn't the only 4-cycle EMD ever used the "H Engine" (or something like that) that was supposed to replace the 710 and allow them to reach the 6000hp mark, and was used in the true SD90MACs?

Yes, that's what I was referring to when I wrote "with one exception -- the ill-fated SD90MAC-H." That locomotive used the 265H engine -- the only 4-cycle engine built by EMD. All other EMD locomotives, including those currently in production, use a 2-cycle design.

D'oh!! Didn't read the whole thing...sorry!

No worries! Today I'm blaming everything on the heat.

So wait, that means that the fuel and oil are mixed? Like in a boat? Why in the world would they do that? What are the advantages?

NellsChoo wrote:So wait, that means that the fuel and oil are mixed? Like in a boat? Why in the world would they do that? What are the advantages?

Actually, no. The EMD two-stroke engine does not mix lubricant with fuel. Check this out:
http://auto.howstuffworks.com/diesel-two-stroke2.htm

Typically, if you have 2ea engines equal weight and displacement, the 2 stroke will be more powerful. Likewise, you can make a 2 stroke engine with the same power output as a 4 stroke but have it weigh much less. I suspect that's why EMD originally went with the 2 stroke design (started by WInton in the early 30's.

The technology of the 1930's would not have allowed a small enough 4 stroke diesel, it would have been too large. The prime mover in CNJ Boxcab #1000 (at the B&O Museum) was huge and only 300HP!!!