Date: Wed, 21 Jun 2000 12:16:36 -0700
Reply-To: Daniel Schmitz <djs@gene.com>
Sender: Vanagon Mailing List <vanagon@gerry.vanagon.com>
From: Daniel Schmitz <djs@gene.com>
Organization: Genentech, Inc.
Subject: Re: 1.9 WBX VS 2.0 AC (long)
Content-Type: text/plain; charset=us-ascii
Richard,
I can comment on both engines, owning both an '82 Adventurewagen and an '87
Westfalia. Opinions put forth are my own.
The air cooled 2.0 in the Vanagon is actually a carryover from the late Type II
Bus of 1976 and later. It makes the same power in the Vanagon as it did in the
Bus (67hp), but it needs to move about 500 lbs more weight and a larger frontal
area. This engine, based on the Type 4 of 1968, was at the height of its 12
year development when chosen to power the Vanagon in 1980, and not much more
could be done to wring more power out of it without sacrificing mileage or
reliability. This is the main reason for the switch to the water-cooled motor
in 1983.5. Water-cooled engines are inherently more efficient because they give
up less combustion energy as heat; more of their combustion energy is available
as power.
***
The air-cooled motor makes about 20% less horsepower than the water cooled 1.9,
(67 vs. 83) and slightly less torque as well. Also, the air-cooled makes it's
torque higher up in the RPM's, whereas the 1.9 has more low-end grunt. Because
of the thermal inefficiency of air cooling, the compression ratio is
necessarily low (7.6:1), where as it can be significantly higher in a water
cooled engine (9:1 in the 2.1) which means more power.
Comparing the two engines is sort of like comparing apples and oranges. The
major advantage of the air-cooled engine is that it lacks a liquid cooling
system and its attendant complexity and maintenance expense.
Having said that, all other advantages fall in favor of the water cooled
engine. More power, quieter operation, better longevity if maintained properly,
and a more flexible power band making the van more enjoyable to drive are the
major ones. Furthermore, the water-cooled engine is a lot easier to work on
because of the lack of cooling sheet metal to get in the way. You can get to
virtually everything from within the engine compartment, whereas on the
air-cooled, much engine and other work has to be done from beneath the vehicle.
The air cooled 2.0 is notorious for cylinder head failures at moderate to high
mileage, most notably dropping of exhaust valve seats, which usually takes the
rest of the engine with it if it happens at speed. The crank, rods, and case
are generally robust, but lean mixtures and overheated conditions can quickly
burn pistons and crack/melt the cylinder heads. This usually occurs without
warning, as the early Vanagons didn't have a temperature gauge, just an idiot
light for oil pressure. Not really helpful if you are running too hot.
With regard to replacement parts, in general the water-cooled engine parts are
no more expensive (and often less expensive!) than parts for the 2.0 engine
(assuming stock replacement parts). If you go with stock pistons and cylinders,
you will discover that the water-cooled set is less costly than the air-cooled
set, although there are many alternatives for air-cooled pistons. New cylinders
heads for the 1.9 are only a bit more expensive than those for the air-cooled,
if you can even find these any more. The engine case and its components share
some of their parts with the old Type 1 1600cc bug engine, as this is the basis
for the water-cooled engine.
Finally, with regard to the expensive cooling system in the water cooled, this
is a reality of the design. However, I feel that regular maintenance and
budgeting for replacement of the cooling hoses periodically more than offsets
the possibility of having to replace an engine that overheats because of
cooling system failure.
***
To summarize my thoughts, having owned and extensively driven an air-cooled
vanagon and now owning a water cooled one, I would not go back to air cooling
if I didn't have to. The advantages of the water cooled design are just too
numerous, and the van is a joy to drive because of it.
In your case, if you are unhappy with the 1.9, I would consider upgrading to a
2.1 (86 and later), as VW made some design improvements to the cooling system,
as well as the fuel injection. That engine makes 95 hp and a whole lot of
torque. I love the way mine drives! I can climb most hills without
downshifting, and I can keep up with 75mph freeway traffic up even minor
grades. It's really an improvement over my '82 van, like night and day.
I suspect that you may regret the change from water cooled to air cooled. A
properly running 2.0 will run and drive just fine, but you will notice a
distinct lack of power and driveability compared to a properly running 1.9 or
2.1 engine.
Hope this helps inform your decision.
Dan
Richard Lynch wrote:
> We are considering (for various reasons) selling our 85 and buying an 80.
> Can anyone offer a driving comparison between the two? I assume the 2.0 is
> less powerful but would like some input from people who have had (or still
> have) both.
>
> Both are standard passenger models.
>
> TIA
>
> Richard Lynch
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