[Vwdiesel] Redline?

[R. Brown]

Tony and Lillie wrote:
> So, what exactly keeps a diesel form being a high RPM engine. I understand the max speed is set at the pump, what I'm wondering is about the internals themselves. As it appears to be exactly the same as a 1.6 gasser, aside from the block and head castings.
>
> What I"m wondering about is the crank, rods, and other rotating assys.
>
> Tony Hoffman
>   

It is mainly due to the diesel combustion process.  Diesel burns in more 
of a spreading flame front from the injector, while in a gas engine you 
have the air and fuel already mixed and a spark sets off the whole thing 
pretty much at once.  Also, with the injector, it takes some time to 
inject all the fuel, so between the time to inject the fuel and the time 
for the fuel to mix with the compressed air and the flame front to 
spread, that is pretty much the limiting factor in top speed.  The 
larger the cylinder diameter, the longer the flame front takes to spread 
across it, so larger engines generally have a lower top end speed than 
smaller engines.

-- 

  Roger