all my diesel vw heads have double valve springs.
a 1.9 VW waterboxer head of mine has double valve springs.
two AMC heads here for waterboxer , have double valve springs.
i.e... .......'that's what's normal' it seems.

I wouldn't quite say that double valve springs are used to prevent valve
float.
I'd say that using double valve springs is a cost effective way to get
enough spring pressure to prevent valve float without going to thicker wire
springs .........since binding of the coils of the springs would be a real
problem.

a fancier way of saying what you said, more or less.
I would now suspect that the single ones are some aftermarket improvement
perhaps.

----- Original Message -----
From: "Jim Felder" <jim.felder@GMAIL.COM>
To: <vanagon@GERRY.VANAGON.COM>
Sent: Sunday, October 11, 2009 5:27 PM
Subject: Re: Dual Valve Springs

Can't speak for Vanagons per se, but generally double valve springs
are used to keep the valves from "floating" permanently open at very
high RPMs. The kinds of RPMs that wasserboxers never see.

There are all kinds of racer and aftermarket performance products for
VWs, maybe someone just had these on hand and knew that they would
fit. Makes me want to look through my junk pile to see what my old
heads have.

Jim

On Sun, Oct 11, 2009 at 7:14 PM, Chris S <szpejankowski@gmail.com> wrote:
> Just picked some nice and clean used 2.1L heads today. They have dual
> valve
> springs, which in my 9 years of Vanagon ownership I have not encountered.
>
> Can someone tell the history of these? I'm assuming it's a factory part.
> What would I gain by using these instead of single springs I currently
> have
> in my 2.1? Both my and the donor engines are '89.
>
> --
> Chris S.
> Disclaimer: "Death and serious injury may occur"
>