2 Stroke Engineering | Where do we go from here?

[troy]

This article is fascinating...if you like to geek out on the HOW and WHY of engine tech.

http://www.cycleworld.com/another-path- ... ter#page-3

[Stu]

KTM engineers said recently that they expect to keep the 2T alive and that direct injection motors are being worked on to meet the Euro4 standards coming up in 2020. If they cannot meet the standards they will continue to sell the 2017 revised 2T engines (which apparently meet Euro3 standards) in markets that don't require compliance such as Australia. Otherwise the 2T offerings will be only closed course models for 2020. The problem with this is that direct injection 2Ts will probably cost nearly as much as a 4T and likely be nearly as complicated.

Stu

[troy]

Agreed on the complexity. As I was reading that article, I was thinking, "yeah, but the real beauty of the 2 stroke is simplicity". If it becomes as complex (and expensive) as a 4 stroke, it will still be a win in power efficiency I guess.

[Stu]

Since 2Ts have power on every stroke heat is their enemy. The extra fuel / oil with piston port designs helps with that but the EPA sniffers have clamped down on the excess going into the atmosphere. (Were we to perfume our pre-mix with cannabis oil do you think that might change the sniffer's attitude toward 2Ts?) Injection systems so far have not successfully dealt with the heat buildup except by reducing power output. That in itself makes new systems less attractive.

Stu

[troy]

The article goes into considerable detail on those issues and more and offers some possible solutions. All of those Solutions however add up to considerable complexity in the design over conventional two strokes.

I don't think he mentions it but those additional components mean more weight as well