Diesel vs Gas Engines

[swall]

Just a general curiosity question. In comparing a diesel to a spark ignition engine, how does valve timing ,valve lift and cam duration compare? Assume two similar displacement engines, both naturally aspirated four strokes.

 

[ivymike]

where are you going to find a naturally aspirated diesel these days?

 

[EHudson]

Durations are a bit less and acceleration rates are higher. The close proximity of valves to pistons usually results in the valves chasing the piston down the bore.

 

[MacRae]

"where are you going to find a naturally aspirated diesel these days?"

many places, almost all small engines <25-50 Hp

 

[ivymike]

Yes, that's true, but I'm guessing that's not the sort of engine comparison he was after. (my assumption was that he's looking for automotive-like applications)

 

[MacRae]

I figured that too, but I just felt I'd mention it.

 

[swall]

Yes, automotive applications. A comparison between valve timing on the Olds "diesel" and it's gas counterpart would be most interesting.

 

[MacRae]

If I remember right the Olds diesel is NA

 

[sbmar]

For sure, you won't see much, if any, valve overlap/valve opening at TDC exhaust in high performance automotive diesels................Tony

Tony Athens

http://www.sbmar.com