efficiencies

[Ric Rainbolt]

>Typical efficiency for a modern efi engine would be around 30-32% at the
>point of maximum efficiency  (WOT 2000 - 5000 rpm).  Overall operating
>efficiency may be 5-10% depending on use.

That's actually fairly useful info!  I have some additional questions:

Q: What is the typical pumping efficiency of a 4 valve small bore engine
(say, around 3" bore)?

Q: Does pumping efficiency typically go down with bore size?

Q: What is a typical mach index for a small bore 4 valve?

Q: How do these numbers change for a 2 valve motor?

Thanks,
Ric Rainbolt
ricrain at computek.net