Upgrading Engine Performance

The Wasserboxer Gas Conversions Diesel Conversions

We all know that the stock T-3 Wasserboxer 2.1 petrol engine is underpowered.  The WBX can be modified to make it perform modestly, but noticeably, better without giving up reliability.  But let's face it, the WBX will always feel underpowered compared to modern cars no matter what you do to it.  For some, this is really not a problem.  The engine is adequate, and even fun with a little tweaking and the right gearing. For others, however, an engine conversion to a more powerful unit is the only solution. 

The most popular conversions are to Subaru, VW I-4, Audi 5 cylinder, or TD or TDI diesel engines.  The Subaru engines are now the most popular conversion in the US.  Diesel conversions are more popular in Europe, but are catching on in the US. 

The Wasserboxer
The Wasserboxer.   The 2.1 WBX is a horizontally opposed engine that delivers a nice, smooth and broad power band with good torque at low RPMs.  It's a reliable engine if maintained to spec and if preventative maintenance is performed.  Fuel injection wear items like the airflow meter, the O2 sensor, the temp II sensor, and the idle switch must be replaced at some point after 90,000 miles.  Water pumps should be replaced every 50,000 miles.  Use only OEM filters, fluids and parts.
Despite its positive attributes, the WBX is definitely under powered.  Some shops offer souped up 2.1 WBX engines that boast significant horsepower increases, but there have been more than a few reports of reduced reliability in some of these engines, so do your research before buying.  As a general rule, the more tweaked an engine is, the less reliable it is, and often the power band is narrowed toward the top RPM range rather than broadened toward the bottom, as would be preferred  with a syncro.  

Modest improvements in performance can be obtained without sacrificing reliability.  Balancing the flywheel and clutch can greatly increase smoothness.  Ceramic coating the heads prevents leaky gaskets resulting from corrosion and helps contain combustion temperatures for better breathing.  Ceramic coating the headers does the same.  If the engine is torn down for rebuild, the pistons crowns should also be ceramic coated.  A free-flowing muffler  (Part Number 17783, some minor mods necessary) and air filter will also help improve breathing.  1.25 ratio rockers are used by some in pursuit of improved low rpm torque.  Chrome molly push rods help lighten the valve train.  (There was a modified ECU chip available for a while, but it narrowed the power band, with a resulting loss of power at the bottom end and an increase at higher  RPMs (4000+).)

These modest upgrades make the WBX smoother, externally cooler running, noticeably perkier and more fun to drive.  Performance can be further enhanced by slightly lowering the gearing.  Lowering gearing modestly broadens the power band, increases the available power at any given RPM and increases acceleration.  This translates into a slightly quicker van that can pull hills better without as much down shifting, but one which loses roughly 4 MPH in cruising speed at the top.  You can still cruise at 70 MPH on the interstates, but gas mileage will suffer.  For dirt roads, secondary roads and two-lane highways, however, the gearing is much improved.  A syncro with a WBX and geraing thus tweaked will perform adequately and be enjoyable to drive for many if not most syncronauts.  Of course, it will not have the power of a good conversion, though.


Gas Conversions

The VW Vanagon Westfalia is nearly perfect for our every need except for its ability to climb even modest grades at speeds traveled by the owners of almost every auto built over the last 40 years. Because of this and the perceived poor engineering by some, many Vanagon owners have experimented with other engines. People have installed American V6 and V8s, Porsche flat 6s, Mazda Rotarys, many variations on the VW in line four (both gas and diesel), several Subaru and even electric motors! The mainstays of the Vanagon engine community, however, are the Subaru, the VW inline four and the VW diesel engines.

In my many years of experience doing conversions, I have found the Subaru engine to be the best choice. First, it is a very good fit.  This engine is a boxer engine that is almost identical in size and weight to the Vanagon engine (4 cylinder engines).  Moreover, a modified oil pan with satisfactory oil capacity can be utilized to maintain stock ground clearance, which is very important to syncro owners.  And there is no need to modify the engine hatch lid. 

Second, the engine performs very well. Since boxer motors of all types are inherently balanced and Subaru engines use a counterweighted crankshaft, they run very smoothly. The engine is so balanced that it happily turns 6500 rpms with no problems.  They are also powerful.  The least powerful of all the Subaru engines used in Vanagons, the EJ22, puts out 130 hp.  More importantly, and unlike the in-line VW conversions, it has 80% of its available torque at 2000 rpm, which is especially important in a syncro. And with the range of Subaru engines that will fit in a Vanagon, you can get up to 250 hp out of a stock motor if you so desire. 

Finally, the Subaru engines have superior technology and construction. These engines have a very stout water pump and timing belt which show almost no discernible wear at 100k miles. These are the same parts that have long been problematic on VW engines.  Subaru engines also use five full size main bearings, four valves per cylinder and a much better engine management system than VW. They have distributor less ignition and continuous drive belts instead of v belts.  Parts availability should also be a factor in any conversion. Subaru parts are very available everywhere in the US.

Ah yes, there must be some drawbacks, aren't there? Of course. A Subaru conversion will take longer to get done that an in line 4 VW which can be done in a little a day or two. Any Subaru conversion takes at least 40 hours of work. Also the Subaru is quite a bit more technically challenging for the do-it-yourselfer than some other conversions.  Cost is also a factor. In most instances a Subaru conversion will cost more than a VW gas engine conversion, but significantly less than a TDI conversion.

What about Diesel?  The question of gas vs. diesel is best answered by asking what you want most from you Vanagon. First let me say that no diesel engine currently running in any Vanagon (including TDI) has the performance to accelerate like a Subaru powered Vanagon.  Driving any diesel vehicle is an acquired taste. The diesel Vanagon will undoubtedly get better fuel economy.  But the TDI engine does not fit under the Vanagon deck lid and may pose emissions certification issues depending on where you live.

The Subaru Conversion List started by Warren Chapman is an excellent resource.

Diesel Conversions

There are many advantages to a TD or TDI diesel conversion for a syncro.  The modern diesel engines put out tremendous amounts of torque at low RPM, get about 30% better gas mileage and can cruise all day at 70+ MPH.  There are downsides, though.  First is cost.  At a minimum, it is about 20% more expensive to do a TD or TDI conversion.  There are few shops set up to do them.  And it is a daunting do-it-yourself job.  In addition, the diesels do not accelerate as well as some of the gas conversions.  Some diesel conversions vibrate and are noisy.  And passing emissions standards can pose hurtles in states like California.  But still, a properly done TDI conversion is an appealing option if you can afford it.

Here are photos of Stew's (UK) TDI conversion performed by Brend Jaeger in Germany.  Stew and his wife stopped by for a visit on their trip from Argentina to the Arctic Ocean in Alaska. 

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