it's true, both heaters work just fine with a subaru engine in a vanagon.
And you think, even, that with a bypass ..
basially a short circuit in the heater circuit ( so there is always full
time flow in the heater circuit to the t-stat , which is how a soobie
t-stat senses engine temp ..via the heater circuit ) that heater
performance would suffer. But it doesn't.

I put a valve in the bypass of my first subaru conversion ..
and never have on all the ones since.

there is only one consideration about 'flow rate' with a subaur engine
in a vanagon ..
and that is at idle for long periods in hot temps.
Since the subaur  cooling system expects the radiator to be just 6
inches from the engine ..
subaru sized the water pump and it's drive pulley for that.

In a vanagon suddenly it's many feet to the radiator.
This isn't an issue at say, 1,700 rpm and above ..
but at idle, for long periods , on a hot day ..
coolant flow will be minimal at an idle of say 800 rpm.
In that case...just hold it to 1,500 rpm or so for a minute ..
and temp will drop right back down since coolant flow improves at that
higher rpm.

and since the w. pump is driven by the timing belt...........there's not
opportunity to fit a smaller drive pulley to the w. pump ..
it's not much of an issue really, this idle flow thing.
and the heaters work just fine usually.
Scott
www.turbovans.com

On 2/17/2012 7:41 PM, Rob wrote:
> At  2/17/2012 02:11 PM, Dennis Haynes wrote:
>> . There may be a design issue with the Subaru engine
>> having enough flow to support the two heaters. A booster pump or a
>> plumbing
>> change can help this.
>>
>> Dennis
>
> A 94 Subaru 2.2 in an '85 Westy and both heaters work great & have
> for several years.
>
>
>
> Rob
>
> becida@comcast.net
> Western Washington State, USA
>