re: radial valve heads (was pushrods)

[James Montebello <jamesm@domain.elided>]

Honda did this more than once, and I believe one of them was with one cam,
not two.  I'm thinking that at least one Italian manufacturer did this
in the 60s, as well.

There are two basic variations I've seen on this.  On one, the cam lobes
weren't ground flat, but angled.  On the other, multiple rockers are
used.

I don't think the Guzzi four-valver is a radial layout (could be wrong
there, not up on the latest developments).  Both Guzzi and BMW produce
four-valve designs that exploit the unusual layout of their engines.
In both cases, these are vee (Guzzi) or boxer (BMW) twins with the intake
and exhaust ports parallel to the crankshaft.  This allows a pushrods
to be mounted "in the vee", with rocker shafts running perpendicular to
the crank line, each shaft operating two fingers that open a valve each.

james montebello

On Sat, 15 Feb 2003, Joe Elliott wrote:

> At 4:12 PM +0000 2/15/03, alfa-digest wrote:
> >The only people I can think of who have radial valve
> >heads are Honda and Aprilia and both of those are on single
> >cylinder engines with twin cams
>
> Can anyone supply a link to cutaway drawings of either of these
> engines?  I'd really like to see how it's done.
>
> Thanks,
> Joe
>
> PS> Now that I think about it, doesn't Moto Guzzi have a 4V (radial)
> hemi that uses pushrods?
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