T-4 Upright Conversion

Converting A T-4 Pancake Engine To An Up-right Configuration


    The type-4 motor is the latest and greatest in the air-cooled VW family.  It's also one of the most misunderstood and BEST motors VW ever produced.

    The 1776 type-1 motor I built for my bus works just great; no complaints.  But hey, I want more power.  It's got plenty of power to keep up with traffic and buzz around as a commuter just fine.  But when I go camping with the family and have it full of gear and have a loaded trailer in tow, it's taxed (and can you really blame it).  I can still cruise at 65 mph just fine, but it's working at it's max capacity the whole time.  In my experience, having a motor at max capacity only spells disaster sooner than later.

    The motor I'm converting is a 2000cc (2.0L) with hydraulic valves from '79 Westfalia camper.  It's got those weird square port heads and was in a pancake configuration.  Pancake motors are motors which have the fan attached to the crankshaft and blow air horizontally across the cylinders.  In order to fit this motor into my bus without cutting the original engine bay sheet metal, it needs to be converted to an up-right fan configuration similar to a type-1 (bug) engine.  My plan is just to completely rebuild this motor but use a more optimal cam, big valve heads, higher CR and a custom header/muffler system, then convert it to upright cooling using modified T-1 & T-4 parts.  

    There are basically 4 major styles of upright conversions for a type-4 motor.  There are many different renditions or each by various companies, but there are really only 4 major styles when all is said and done:

1.  The Next Generation conversion (A.K.A. - the "Cali conversion").  This is a DIY conversion where you fabricate most of your own parts by modifying stock T-1 and T-4 parts.  This is the ONLY kit that enables the user to retain the stock thermostat system.  This is a VERY inexpensive way to go if you have some basic tools and can do some basic fabrication.

2.  The Raby's Aircooled Technology, Down The Middle shroud conversion (A.K.A. - "The DTM").  This is a pre-fabricated kit which is purchased ready to install.  It features  a gel coated fiberglass one-piece shroud/cylinder covers which are uniquely made to direct cooling air directly between each cylinder bank which maximizes cooling.

3.  A Porsche 911 style kit.  These kits, made by various manufacturers, use either a true 911 fan/alternator or a replica 911 fan w/ a modified alternator and a fiberglass shroud.  These are not necessarily "Bolt-on" and must be trimmed to fit your motor.  Most systems also require the breather chimney to be milled down making it necessary to completely disassemble the motor to make it possible to fit one of these systems.

4.  A Corvair style kit.  This kit uses a fan similar to the Porsche 911 kits, but rather than the fan being in a vertical configuration, it lays horizontally and blows air down onto the cylinders just like the old Chevy Corvairs.   Like the Porsche 911 kits, these are not necessarily "Bolt-on" and must be trimmed to fit your motor.

    Since I'm on a tight budget, I chose the "Cali Conversion method.  This project was started by ordering the Next Generation Type IV Upright Conversion Manual, by Joe Cali.  I HIGHLY RECOMMEND getting his manual regardless of the type of conversion you plan to do.  This book is full of good information and is worth it's weight in gold for anyone considering swapping to a type 4 motor.

Crank Pulley Modification/Fabrication

Alternator/Generator Pulley Modification

Alternator/Generator Stand Fabrication

Upper Cylinder Tin Fabrication

Lower Cylinder Tin Fabrication

Oil Cooler/Fan Shroud Modification

Dip Stick Fabrication

Type-4 Custom Header Fabrication

Finished & Installed Engine Photos 


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Revised: January 20, 2007 .