The VW Air-Cooled Engine E-Book

Ken Cservenka

• Herausgeber: Crowood
• Kategorie: Lebensstil
• Sprache: Englisch

Seitenzahl: 196

Veröffentlichungsjahr: 2018

Beschreibung

The VW Air-Cooled Engine is a no-nonsense engine manual that any practical-minded person can understand, giving a highly illustrated step-by-step guide to dismantling and rebuilding a Type 1 engine. Most of the operations described in the book can be applied to the Type 4 unit used in 1700, 1800 and 2-litre Transporter models as well. Topics covered included workshop essentials; keeping the engine healthy; removing and stripping down the engine; examination of the engine components; reassembling the engine and ancillaries and full specifications of the various Type 1 and Type 4 engines. With over 300 colour images, this book will be an invaluable resource for anyone involved in the repair and maintenance of these iconic engines.

Leseprobe

The VW

Air-Cooled Engine

Repair and Maintenance

Ken Cservenka

THE CROWOOD PRESS

First published in 2018 by

The Crowood Press Ltd

Ramsbury, Marlborough

Wiltshire SN8 2HR

www.crowood.com

This e-book first published in 2018

© Ken Cservenka 2018

All rights reserved. This e-book is copyright material and must not be copied, reproduced, transferred, distributed, leased, licensed or publicly performed or used in any way except as specifically permitted in writing by the publishers, as allowed under the terms and conditions under which it was purchased or as strictly permitted by applicable copyright law. Any unauthorised distribution or use of thistext may be a direct infringement of the author’s and publisher’s rights, and those responsible may be liable in law accordingly.

British Library Cataloguing-in-Publication Data

A catalogue record for this book is available from the British Library.

ISBN 978 1 78500 376 9

CONTENTS

Preface and Acknowledgements

1. Workshop Essentials

2. The Type 1 Engine: Keeping it Healthy

3. Engine Removal

4. Removing the Exhaust and Ancillaries on Type 1 Engines

5. Engine Strip-Down

6. Examination of the Engine Components

7. Assembling the Crankshaft

8. Rebuilding the Crankcase

9. Removing the Exhaust and Ancillaries on 1700, 1800 and 2-Litre Type 4 Engines

10. Reassembling the Pistons and Cylinders

11. Rebuilding and Installing the Cylinder Heads

12. Replacing Ancillaries and Exhaust on Type 1 Engines

13. Replacing Ancillaries on 1700, 1800 and 2-Litre Type 4 Engines

Appendix I: Specifications

Appendix II: Engine and Chassis Numbers

Useful Addresses

Glossary

Index

PREFACE

I was first introduced to the Volkswagen marque by a family friend of one of my school friends; from memory, it was an oval-windowed 1955 model and I was fascinated by the engine note, the fact that it always started within seconds and the glowing reports from the owner. I then thought nothing more about Volkswagens until I visited a friend down in Devon who owned a 1967 1500 Beetle. We went out in the Beetle and on the way to his home I was asked if I wanted to drive it, a chance I jumped at. As we were travelling at 40mph in top gear my friend told me to press the clutch pedal, which I did. My friend then slammed the gear lever into second and told me to release the clutch pedal. The car screamed in protest but my friend stated that in any other car the gearbox would have exploded. I was already hooked before this amazing demonstration and on Guy Fawkes night 1969 I bought my first Beetle – a 1963 1200 Deluxe. I drove that car until 1983 and covered over 160,000 miles, including camping trips with my wife and three children with all the gear. I then bought a 1968 auto stick-shift Beetle; and in 1989 a 1974 Bay Window camper, a Devon Eurovette conversion, joined the fleet. I also own a 1967 1500 Beetle and it is this car that is featured in the Type 1 engine rebuild in this book. I moved to the Cirencester area in 1972 and as well as repairing my own Beetle I repaired and serviced many air-cooled Beetles and Type 2 vehicles from the local area. In writing this book my aim was to produce a no-nonsense engine manual that any practical-minded person can understand, with a step-by-step guide to building a Type 1 engine. Most operations described can be applied to the Type 4 unit used in 1700, 1800 and 2-litre Transporter models as well. I have deliberately not gone into such technicalities as blueprinting as it is unnecessary on an engine built for everyday usage.

ACKNOWLEDGEMENTS

I would like to thank the following for their help in producing this book: Richard Copping for encouraging me to write this book; Neil Birkitt for looking over my words and helpful advice; the guys at the Engine Shop, especially Jim Gray, for the machine work on the crankcase and crankshaft; Richard Hulin for further machine work and for allowing me the run of his workshop to take photographs of a Type 4 engine; and finally my wife, Mary, for her patience and understanding.

CHAPTER 1

WORKSHOP ESSENTIALS

The Volkswagen air-cooled engine is relatively simple to maintain and repair and, although the flat-four layout is fairly unconventional today, a few well-chosen garage essentials and tools are all that is needed for the home mechanic to be able to tackle most jobs.

A good start is the tool kit that was supplied with the car, consisting of a body jack, a few useful spanners, hub cap-removal tool and a double-ended box spanner. One end of the box spanner is for removal of the wheel bolts while the other end doubles as a spark plug removal tool and is the correct size to remove or tighten the nut on the generator – especially useful for replacing a broken fan belt out on the highway.

However, the body jack should only be used to change a wheel in the event of a puncture out on the road, as it isn’t suitable for any major repairs. The tool kit supplied with the car should be kept in the car with a few additions for problems encountered when away from home. I personally carry the tools shown in Figs 1.2 and 1.3.

Fig 1.2 Spanners for maintenance of air-cooled Volkswagen engines: 1) ring spanners, 6–22mm; 2) additional 21mm spanner for generator pulley nut, Type 1 engine; 3) open-ended spanners, 6–22mm; 4) additional 30mm combination spanner for the crankshaft pulley nut, Type 1 engine.

Fig 1.3 Other basic tools for working on the air-cooled engines: 1) locking pliers; 2) expanding pliers; 3) pliers; 4) metric feeler gauges; 5) assortment of screwdrivers; 6) hammer.

Some of the repair procedures described in this book involve using heat, either a blowlamp or boiling water, so for safety wear leather welding gloves, as the components are very hot to handle. When using a blowlamp or in any situation where metal fragments may become airborne, always protect your eyes with safety glasses or goggles. (Fig 1.1)

Fig 1.1 Safety equipment includes leather welding gloves for handling hot components and safety glasses.

Good-quality spanners are a must for a well-equipped workshop, with both ring and open-ended ones having their uses. When buying ring spanners, look for ones where the effort is exerted on the flat of the nut, not the corners. Buy sets that include the range of sizes from 6mm to 22mm. Additional sizes that are useful are 30mm for the crankshaft pulley nut, and 21mm for the generator pulley nut, though the VW box spanner will do for the latter.

Other useful tools to carry in the vehicle or at your workshop include locking pliers, often referred to by the trade names of mole grips or vice grips. The expandable pliers (gas pliers) used by the plumbing trade are another valuable addition, as are regular pliers. Feeler gauges and various sizes of screwdriver are used for valve clearances and adjusting the contact breaker points or spark plug gaps. Finally, no toolbox should be without a hammer – though not to be used on the crankcase or cylinder heads.

Fig 1.4 Specialist tools for more advanced engine work: 1) centre punch; 2) Allen keys; 3) twelve-point, 8mm socket and Allen key inserts; 4) micrometer; 5) tool to press in crankshaft oil seal; 6) piston-ring clamp; 7) flat-ended circlip pliers; 8) long-nosed pliers; 9) extendable magnet; 10) pipe clamp.

For more advanced work the following tools have specific roles when rebuilding an air-cooled Volkswagen engine. Allen key bolts and those with a 12pt internal spline are used mostly on the 1700, 1800 and 2-litre engines. When rebuilding the crankshaft on earlier Type 1 engines, a centre punch is used to peen the rim of the nut into an indentation on the connecting rod. When measuring the crankshaft end float using feeler gauges, a micrometer is used to select the third shim. The flywheel oil seal on Type 1 engines is pressed in using a circular tool in conjunction with the flywheel retaining bolt. This can also be achieved with a block of wood and a mallet. When installing the cylinder barrel over the piston it is advisable to use a piston ring clamp as the rings are easily broken.

When stripping down or assembling the gears onto the crankshaft, they are held in place by a circlip. However, the usual style of circlip pliers with pointed ends to grip the holes in the circlip are useless for this job; instead, use circlip pliers with stout flattened jaws that insert between the ends of the circlip to open it out.

When removing the valves from the cylinder head, an extendable magnet or long-nosed pliers are essential to retrieve the collets.

The petrol tank on first- and second-generation Transporter models is situated above the engine; it is therefore essential to clamp the flexible pipe before disconnecting it from the engine. The pipe should be plugged and the clamp removed to avoid damaging the rubber pipe.

It often becomes apparent when working on an engine that special tools used by the dealer are not readily available, so it becomes necessary to apply a bit of ingenuity to either make or adapt tools to complete the job. For example Fig 1.5 shows a puller made specially to remove a particularly stubborn crankshaft pulley. The rubber suction valve-grinding tool illustrated is readily available from most motor factors or tool suppliers. A length of stout wire from a coat hanger has its uses, such as installing the thrust washers at the base of the distributor drive shaft and positioning the anti-chatter spring in the depression in the top of the shaft. When installing the cylinder barrels over the pistons, lengths of copper tube in conjunction with a cylinder head washer and nut hold the barrel in place while the crankshaft is turned to present the next piston.

Fig 1.5 Home-made or adapted tools also have a role in advanced engine work. With the exception of item 2, all the items shown here are home-made or adapted from other uses: 1) home-made puller for removing the crankshaft pulley on Type 1 engines; 2) rubber suction tool for valve grinding; 3) a length of stout wire made from a coat hanger used to install the two washers in the distributor driveshaft bore and the anti-chatter spring in the top of the shaft; 4) copper tubes used to retain the cylinder barrels; 5) wooden tool for removing and installing the distributor driveshaft; 6) a Beetle king pin, now a drift for installing piston pins; 7) wire spring clips to retain cam followers.

A wooden peg, whittled to fit the depression in the distributor drive shaft, is used when removing or installing the shaft. If it proves to be stubborn to remove, an expensive tool is available but in this situation it is better to remove the shaft when the crankcase is opened.

When removing a piston, a Beetle king pin or similar is useful for drifting the pin out. The wire clips in Fig 1.5 were packing pieces used to hold a piece of machinery and were about to be thrown out. They have proved to be very useful for holding the cam followers in the right-hand case half when assembling an engine.

Fig 1.6 Installing the two gears and the spacer onto the crankshaft: 1) a length of steel tubing purchased from a local metal supplier makes a suitable drift; 2) the flat-ended circlip pliers are used to fit the retaining circlip; 3) a gunmetal hammer will not damage steel components.

When installing the cam gear, spacer and distributor drive gear onto the crankshaft, always wear leather welding gloves as they are very hot when removed from the boiling water. A length of metal tubing from a local metal supplier is a useful homemade tool to drift the gears into position. Flat-ended circlip pliers are used to install the circlip.

Fig 1.7 1) Gearbox input shaft used to hold the drive plate when installing the clutch pressure plate; 2) a plastic tool for holding the clutch plate; 3) flywheel lock; 4) a length of angle iron bolted to the flywheel using the clutch bolts is a safer option for holding the flywheel when tightening the high-torque bolt used on the Type 1 engine ; 5) torque wrench and 13mm socket for tightening the clutch bolts.

A well-equipped workshop will have the necessary tools to remove and install the clutch. The best option to hold the clutch-driven plate in position is a gearbox input shaft obtained from a scrap gearbox. Plastic tools to replicate the input shaft are also available. When fitting the clutch, use a flywheel locking tool that bolts to the top nut on the crankcase. It is best to lock the flywheel in position using a length of angle iron bolted between two of the clutch bolt holes.

Fig 1.8 1) a ½indrive socket set; 2) a ⁄8in-drive long-reach and short socket sets and ratchet driver; 3) a 1in-drive 36mm socket and sliding T-bar for tightening the flywheel-retaining bolt; 4) torque wrench with a range of 5–40lb ft (7–54Nm).

A socket set is always a good investment; ½in drive socket sets were the preferred choice when I obtained mine in the late 1960s, but ⅜ drive sets are now widely available and are often the preferred choice, especially when there is limited access. A ¾ or 1in drive 36mm socket and sliding T bar is necessary to remove and install the high torque flywheel bolt on Type 1 engines. Another essential when working on engines is a torque wrench with a range of 5lb ft (7Nm) to 40lb ft (54Nm).

Fig 1.9 A trolley jack and axle stands are essential when removing or installing the air-cooled engine. The blocks are a useful addition to stand the unit on.

A trolley jack with a good maximum lift height and axle stands are essential for removing or installing the air-cooled engines. Unlike other makes, which remove the engine with a crane through the bonnet aperture, the Volkswagen air-cooled engine is removed from under the vehicle. A pair of solid wooden blocks is useful for lowering the engine onto before removing any blocks used between the engine and the jack.

CHAPTER 2

THE TYPE 1 ENGINE: KEEPING IT HEALTHY

To keep your Volkswagen engine running sweetly and in tip-top condition, there are maintenance procedures that need relatively frequent attention. Unlike vehicles produced in the twenty-first century, we don’t have the luxury of service intervals of 10,000 miles or more. Instead, the Type 1 engine requires checking weekly, with the major service scheduled for every 3,000 miles or 5,000km.

To illustrate this point, a good example is the fan belt, which not only drives the large fan that provides the all-important cooling air to the cylinders and cylinder heads, but also drives the generator to keep the battery topped up. A slack belt will prevent the fan from supplying sufficient cooling air at higher speeds and will also starve the battery of the power to keep it at maximum efficiency.

WEEKLY CHECKS, EVERY 300 MILES OR 500KM

1. Fan belt tension; check 300 miles after fitting a new belt (see 3,000-mile service below).

2. Engine oil level.

ENGINE SERVICE, EVERY 3,000 MILES OR 5,000KM

1. Check and adjust fan belt tension.

2. Change engine oil and clean oil strainer.

3. Clean and service air filter.

4. Clean fuel pump filter (early engines only).

5. Check the condition of ignition leads, distributor cap and rotor arm.

6. Clean and adjust contact breaker points.

7. Check and reset ignition timing.

8. Check spark plugs.

9. Check clutch pedal free play.

10. Check valve clearances (adjust tappets).

FAN BELT TENSION, TYPE 1 ENGINE

Fig 2.1 The fan belt should be free of cracks or fraying. It is wise to keep a spare in the car.

As this is an air-cooled engine, a spare fan belt and the necessary tools to replace it should always be kept in the vehicle. If the belt breaks, indicated by the red ignition warning light coming on, stop the vehicle as soon as it is safe to do so and switch the engine off. While the car can continue for some time before the battery goes flat, the Type 1 engine will quickly overheat and be rendered irreparable without the cooling effect of the fan.

Generally, if you can see the fan belt flexing when the engine is running, it will need adjusting. To check it properly, first turn off the ignition and remove the key from the switch. Depress the belt halfway between the pulleys; the deflection should be no more than 13mm on the early engines produced before the 1967 model year, or 10mm on the 1500cc engine and all models produced since. If the deflection is more than the above values the belt will need adjusting. Also examine the belt for signs of ageing, cracking or polishing and replace it if in any doubt.

Volkswagen didn’t follow the usual route of providing an adjustable belt-tensioning device for the Type 1 engine; instead they used a tapered split generator pulley, fitted with shims between each half. By removing shims the V-shaped fan belt rides higher up the pulley, effectively increasing its diameter to take up any free play.

Fan Belt Adjustment or Replacement (Figs 2.2–2.3)

Tools required:

• Medium to large flat-blade screwdriver

• 21mm ring spanner, socket or the multi-purpose box spanner supplied with the vehicle

• 30mm open-ended or ring spanner (optional)

Fig 2.2 A screwdriver held against the screw through the cutout in the pulley is used to stop the pulley turning while the nut is undone.

1. Using the 21mm ring or the multi-purpose box spanner, turn the nut holding the generator pulley clockwise until the cutout on the forward edge of the inner pulley half is just past top centre. Insert the screwdriver so that the tip rests against the top generator housing bolt, thus preventing the pulley from turning while the nut is loosened.

Fig 2.3 The fan belt is adjusted by adding or removing shims between the pulley halves. The spare shims are kept between the domed cap and the pulley.

2. Remove the nut, followed by the conical spacer, spare shims and the outer pulley half. There should now be some shims left between the two pulleys; if not, the belt will need replacing. Remove one shim and add it to the pack of spare shims removed before the outer pulley.

3. Before reassembly examine the belt for excessive wear or fraying. If in doubt, replace the belt – your engine’s life depends on it! If replacing the belt on later engines, remove the cover over the crankshaft pulley bolt, which is held by three 6mm slotted tinware screws.

4. Fit the belt into the groove of the lower pulley and then offer the belt up to the inner half of the generator pulley. Having already removed a shim from between the pulley halves, fit the outer pulley, taking care to locate the lugs on the outer half into the slots on the inner half. Replace the outer shim pack, including the shim removed from between the pulley halves, followed by the conical spacer and finally the nut. It is easier to allow the engine to rotate while tightening the bolt, as this helps to locate the belt into the correct position. Finally, tighten the nut fully, having wedged the screwdriver into the slot on the back of the inner pulley but this time against the left-hand edge of the generator housing bolt. Re-check the belt tension and if not satisfied repeat the above procedure. Do not over-tighten the belt, as the extra load can damage the bearings in the generator.

Fig 2.4 Later models are fitted with a guard over the crankshaft pulley nut. Very early split-window models had a bracket that could be swivelled into position so a starting handle could engage with a dog on the pulley nut.

Part Numbers

111 903 137

Fan belt, width 13mm, 25 PS

111 903 137D

Fan belt, width 9.5mm, all models, dynamo

111 903 137E

Fan belt, width 11.3mm, all models, alternator

GENERATOR BELT ADJUSTMENT OR REPLACEMENT, TYPE 3 ENGINE (FIGS 2.5–2.6)

Fig 2.5 The fan belt adjustment on Type 3 models hides under the black cover to the right of the blue coil.

Fig 2.6 The cover removed on a Type 3 engine to reveal a similar set-up for adjusting the fan belt as found on Type 1 units.

The engine fitted to the Volkswagen Type 3 is essentially the same unit as fitted to the Type 1. However, the cooling fan is fitted directly to the crankshaft, within an entirely different and flatter housing, giving rise to the unit being described as a ‘suitcase-style’ engine. The generator is located to the left of the distributor on this engine and the adjustment of its drive belt can be carried out after removal of the air intake housing cover.

The adjustment procedure is essentially the same as described above for the Type 1, except that the pulley is retained by two nuts. The inner 27mm nut can be held with one spanner while a second spanner loosens the outer 21mm nut.

The belt tension is correct when the deflection is 15mm when pressed halfway between the pulleys. From August 1971 this deflection was reduced to 6mm.

ENGINE OIL LEVEL (FIG 2.7)

Fig 2.7 Oil filler cap and dipstick as fitted on all Type 1 engines.

The engine oil is an important component of the cooling system, along with the airflow created by the fan. The oil serves as a heat sink, and is cooled by the airflow from the fan as it passes through the oil cooler mounted within the fan housing. Insufficient oil volume can cause the engine to run hot.

It is just as important not to overfill the engine, as the pulley end of the crankshaft doesn’t have an oil seal; instead, the crankshaft is fitted with a concave oil deflector plate to steer any stray oil back into the crankcase. This plate is ineffective if the engine is overfilled, resulting in oil leaking out behind the pulley and being sprayed all over the engine compartment.

The oil level should be checked weekly, or before any long journey is undertaken, and topped up to no higher than the top mark on the dipstick. However, never let the level fall below the lower mark. It takes half a litre of oil to fill between the top and lower marks on the dipstick.

Engine Oil Change and Oil Strainer Clean (Figs 2.8–2.10)

Tools and parts required:

• 21mm ring spanner, socket or the multi-purpose box spanner supplied with the vehicle

• 10mm ring spanner or socket

• Oil drain pan (DIY tip: use a 5-litre plastic container with a hole cut in the flat side)

• Container for the used oil

• Disposable gloves

• Oil-change gasket set

• Oil filter (from August 1992 only, Mexican-built Beetle models)

• Suitable oil filter removal tool for late Mexican Beetle models

• Oil

• Funnel

Oil capacity:

• 2.5 litres for all models except Mexican-built models with fuel injection

• 3 litres for Mexican cars with fuel injection, and for T3 CT engine

Torque wrench settings:

• 6mm cap nuts

10mm socket

5lb ft (7Nm)

• Drain plug

21mm socket

25lb ft (34Nm)

Fig 2.8 Cover under the engine for the oil strainer. Some later engines didn’t have a drain plug.

1.