Date: Wed, 29 Jul 1998 14:50:03 EDT
Reply-To: FrankGRUN@AOL.COM
Sender: Vanagon Mailing List <Vanagon@vanagon.com>
From: Frank Grunthaner <FrankGRUN@AOL.COM>
Subject: Re: Eurospec Conversion: Digifant Comment
Content-type: text/plain; charset=US-ASCII
I've been following these exchanges on engine conversion questions for many
years. As a consequence, I converted my '82 Diesel Westfalia to gasoline power
after considerable research and many helpful inputs from list members such as
Alstair Bell. The conversion began in September of '95, went on the road in
Jan. '96, and is nearly finished (got the Air Conditioner up this weekend,
only the subwoofer remains). I used an 8V 1.8L DIGIFANT engine from a '90 GTI
donor with malice a forethought! I also used a K&N air filter system,
fabricated an air introduction system interfaced to the original diesel inlet
system in the driver's side rear compartment, added a adjustable cam gear for
4 degree retard on valve timing to shift the torque max to lower rpm, added a
dual downdraft exhaust manifold from a GLI, made a dual pipe exhaust system to
catalyst to dual port muffler, modified the alternator to build in the rear
segment from a Porsche 944 and routed fresh air to the rear of the alternator
pickup. I also use a dual battery setup in the right rear location, added air
conditioning using the GTI AC compressor with additional evaporator, condensor
air handling components from an '85 Westfalia, and kept the diesel trans.
My point is that the digifant engine has been superb. It installed quite
easily compared to the CIS routing nightmare. It has proved extremely
reliable, highly efficient (I range from 18 to 22 mpg). The van pulls
beautifully from 2000 RPM and redlines (6500) in any gear (1st through 4th). I
readily pull the 2 freeway between the 134 and the 210 (Southern California
coordinates) with a full camper load (wife, me, 10 year old daughter, two
dogs, Westy tent, provisions, hot shower system, etc) at 70 mph, and the
calibrated temp gauge holds just below the LED. Under these conditions, the
engine manifold vacuum is 6 inches. On the open freeway, 65 mph cruise
corresponds to 12 inches, and this drops to 10 for 75. Max speed I have had it
up to on the the interstate is 95 and I am not at full throttle. BTW, the
weight of the Westfalia also includes my supplemental gas tank which gives me
a net 26.8 gallon fual capacity. This level of performance is more than
adequate and stresses the capability of the chassis. I have not yet finished
horsepower tests (road g-meter) nor acceleration times, but other measurements
are consistant with 105 to 110 hp from this RV engine. The added power
possibilities from the CIS system, from my experience are expensive, and more
relevant to other watercooled VW applications. Finally the knock sensor/ EFI
Digifant system does a remarkable job of maximizing timing advance over a wide
range on temperatures and pressures (read mountain elevations). Clean
contacts, and a careful study of the wiring diagram together with a copy of
the Golf/Jetta/GTI Bentley (a real workshop manual as compared to the joke of
a vanagon edition) and replacement of simple sensors will handle any problem
I've encountered.
Second point, all these discussions about changing the diesel trans to lower
engine rpm. Nonesense. The dynamic range of the engine is well matched to the
weight of the vehicle --- its a 1.8 liter engine! Torque to the road is
certainly related to engine displacement, and gearing. Gearing is a good
substitute for displacement. I did go to 27/8.50x14 BFG tires to reduce rpm
and correct speedo (less than 0.2% error in my measurements) and odometer. The
current engine speed at 70 mph in the vanagon is similar to daily cruising
throughout Germany on the Autobahn in any rental Golf, Polo, Opel or Ford (by
my rental experience) and these engines return in excess of 200,000 km
lifetimes before head work or overhaul. In my application/installation, I
monitor oil temperature, oil pressure, voltage (both batteries), current,
manifold vacuum, coolant temperature and exhaust manifold temperature. At 75
mph, on southern california freeways, full load and 90 F outside temperatures,
my engine oil temperature ranges from 245 F to 250 F. Highest temperature I
have seen with this setup was 262 F (using Mobil 1 synthetic 15W-50) going up
the Grapevine at a steady 60 mph.
So, in my experience, the 1.8 L/ 8V Digifant engine with diesel trans is an
outstanding package.. reliable, strong, efficient and fun. I remain bewildered
as to why VW didnt standardize on this configuration. Sorry for the length but
I had to finally get this comment out.
Of course, the 2.0 liter engine would be even better, and the Digifant/ nee
Motronic system is just fine. I anticipate that the Eurospec conversion will
be a screamer. More power to Kyle for putting it together.
Frank Grunthaner
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