Volvo Amazon Powertrain and Armament

Starting with the PV 444, Volvo introduced a new generation of four cylindered engines that up until only a few years ago were the very heart and soul of Volvo cars. Countless engines have driven Sweden's car park through the years, but few have been as robust and reliable as Volvo's cast iron engines B16, B18 and B20 (also B14, B21 and B23) which all were based on the B4 engine from 1944. Volvo Amazon was introduced in 1956 with the B16 A as only alternative but came through the years to include also the B18 A and B20 A in the standard edition (121) and the B16 B, B18 B, B18 D and B20 B in its sport editions (122 S and 123 GT).

Engine Outputs

Engine outputs are presented in official Volvo figures, showing both the DIN (Deutsches Institut für Normung) and the more optimistic SAE (Society of Automotive Engineers) values in number of horsepowers. Output is measured in Watts, where one horsepower (DIN) equals 746 Watts. In other words, the engine output in Volvo Amazon has varied between 45kW and 75kW. Changes and differences in engine output between different editions (A, B, D) of the same engine has almost exclusively been achieved by Volvo through different carburettors, cam shafts and cylinder head gasket thicknesses.

The table is a complete record of the engines that were factory installed in the Volvo Amazon and is listed after the engine part number. Also listed are camshaft marking, gearbox and rear axis gear ratio.

* 13191x refers to Volvo Amazon Favorit assembled abroad.
** Please refer to the section on Rear Axis below regarding the 4.55:1 ratio.
*** Spare part engines are delivered without flywheel casing, flywheel, thermostat, water pipes, manifolds, fuel pump, starter motor, distributor, generator and crankcase ventilation.

Trim Kits

Volvo was very successful on the international competition scene in the early and mid 1960s. Gunnar Andersson, successful Swedish rally driver, was convinced in 1962 by Volvo CEO Gunnar Engellau to head Volvo's new Competition Service department. This was no easy decision for Andersson who was at the peak of his career with a European Rally Champion title, but was made somewhat easier when Engellau pointed out that Andersson at Volvo would be working full time with what had been his private hobby for several years. Volvo built a series of 1,000 Volvo Amazon that were very capable for sport and competition use. Some 800 units were built in Gothenburg and the remaining 200 units were finished at assembly plants abroad. The competition version of the Volvo Amazon quickly became both popular and competitive, and was very appreciated among rally drivers. This was the reason why Volvo started selling a trim kit for Volvo Amazon also directly to customers. The cars that left Volvo Competition Service with theses special trim kits were often referred to as Rally Sport or R edition by the customers, a name and a feature that Volvo use still today.

Carburetors

The carburetor armament has also varied during the years, but the cars were consistently delivered with single carburetor setup on the A engines (standard and special editions) and dual carburetor setup on the B and D engines (sport and GT editions). The makes were with few exceptions Zenith and Zenith-Stromberg respectively on the A engines and Skinners Union (SU) on the B and D engines. On some markets the B20 A engine was fitted with one SU HS 6 carburetter, but this may have concerned only the 140-series.

* Zenith-Stromberg 175 CD on early editions, Zenith-Stromberg 175 CD-2S on late editions (not related to markets).
** P 220 in 122 S edition from model year 1963 (some markets, including USA).
*** Zenith-Stromberg 175 CD-2 and CD-2SE on cars sold in the USA and Canada. Both markets are mentioned in the B20 spare parts catalogue.

Gearboxes

In the beginning the Volvo Amazon inherits a lot of its mechanics from the predecessor PV 444 and this includes the gearbox, which for the first model year is a three gear transmission labeled H6 with unsynchronized first and with reverese gear. Unsynchronized first means that the driver has to step on the clutch twice in order to enter the first gear. Already when introduced, there are complaints about the missing fourth gear and when introducing the following model year the Volvo Amazon is fitted with a new and fully synchronized four gear transmission. It is initially labeled M3 but this is changed just in time for the introduction (but some shop literature had already been printed with references to M3). The M4 is fitted in both Volvo Amazon and Volvo Amazon Sport. The M4 was developed and used as base for the major transmission changes that came with model year 1961, when gearboxes M30, M31, M40 and M41 replaced the M4. The three first were available on the standard edition while the two latter were available on the sport edition, with a few exceptions (see below). The first digit states the number of gears (three or four) while the last digit state overdrive (1) or not (0). The body was adjusted on model year 1961 cars to fit the new gearboxes, which are bigger than the predecessors, and consequently it is not possible to retrofit them on earlier model years. From model year 1964 there is also an automatic transmission available on the Volvo Amazon. This was manufactured by Borg & Warner, labeled BW35 and is a three step tranny notorious for the high fuel consumption it caused.

Overdrive came with the new gearboxes M31 and M41 in 1961 and are found in combination with the B16 engine only that model year. Overdrive is like a fifth gear, and is so adjusted that it is ideal for driving in high speeds on flat roads (in other words, it is not designed for acceleration). The overdrive units for M31 and M41 were manufactured by Laycock de Normanville and are a smaller and separate gearbox fitted behind the regular gearbox, i.e. on the outgoing shaft from the gearbox on the propeller shaft. The overdrive is locked to the second and third gears on the M31 and to the fourth gear on the M41, and is not an ordinary gear controlled by the gear shift lever but toggled by an electric switch. On the Volvo Amazon, this switch is located on the steering wheel pole cover on the opposite side to the turn signal switch (the switch also has an identical design as the turn signal switch). A red indicator lamp placed on the instrument panel between and above the lighter and the fan knob indicates the position of the switch (on or off). The overdrive units were of type D 1961 - 1968 (in combination with the B18 engine) and of type J in 1969 - 1970 (with the B20 engine). Type J is a more robust and reliable construction while type D has a higher rpm reduction (0.756:1 or approximately 24 % compared to 0.797:1 or approximately 20 % for the type J). Type J also comes with an improved hydraulic system that provides smoother kick in/out and is less sensitive to polutions thanks to an added fine particle filter in the pressure line. Type D is wired with a relay in the engine compartment while type J is wired directly to +12 VDC (after the 25 A fuse). Overdive was not available on all markets and can not be found on export cars to the USA, and also not on all bodies (not on the Estate, P 220).

* The M4 was called M3 during early development and some shop literature had already been printed when the name was changed.
** The M31 is found as option only on the 121 and only in 1961; examples include chassis numbers 61167 and 67458.
*** Sometimes called M40GV where GV stands for floor lever. Also available with steering wheel lever on P 120 cars with B18 engine as M40RV.
**** A variant of the M40 with bigger flywheel companion flange (380606, also on M30). Part number 254584.
***** The M41 is available as option on the 122 S until 1966, from 1967 exclusively on the 123 GT. Not on cars sold in the USA.

The gearboxes have the following ratios per gear:

* The M31 has overdrive on both second and third gears and is, in principle, equiped with five gears. The second gear with overdrive has the ratio 1.17:1 (= 1.55 * 0.756).
** Includes M40RV (steering wheel lever).

Automatic clutch of the type saxomat, a.k.a. saxomatic clutch, is available as option for both 121 (B16 A) and 122 S (B16 B) model year 1961, probably only in combination with the gearboxes M30 and M40 (i.e. not with overdrive). Saxomatic clutch does not affect the gear ratios. All gearboxes are listed below per part number. Please note that not all combinations were available on all markets.

* Volvo Amazon Favorit. Also 13191x (Favorit assembled abroad).

Rear Axles

The two splines in the drive unit called pinion and crownwheel define the ratio on a rear axle. The number of splines on pinion and crownwheel and their relation to eachother sets the ratio. Take for example the ratio 4.1:1 in which the entering axle (pinion with the propeller shaft) has 10 splines and the exiting axle (crownwheel with drive shaft and rear wheels) has 41 splines. The pinion will then rotate 41/10 (=4.1) times for every round the wheels rotate.

Both the rear axles and their ratios have varied with model years and editions. The rear axle ratios found on Volvo Amazon are 4.56:1, 4.55:1, 4.3:1 and 4.1:1*. The first model years, with the B16 engine (1957 - 1961), have rear axles from ENV and Spicer (model 23) with the ratio 4.56:1. The cars were randomly fitted with rear axles of both brands without any apparent order, although the spare parts catalogue lists what chassis numbers got what brand. With the B18 engine (1962) the ratio is changed on cars without overdrive (both 121 and 122 S) to 4.1:1* while cars with overdrive (122 S ordered with M41) keeps the ratio 4.56:1. The brands are still ENV* and Spicer (now model 27); again the spare parts catalogue lists what chassis numbers were fitted with what axle. The rear axle mantle is changed on the ENV axis during model year 1964 to fit the drive units from the Spicer axle. The Spicer 27 rear axle (and later Spicer 30) was also manufactured by Hayes from late model year 1964. The American axle and driveshaft manufacturer Spicer Corp. was renamed to Dana Corp. in 1928 when the company relocated from New Jersey to Toledo, Ohio while many of the products kept the name Spicer for several decades. Spicer 27, 30, etc. are in other words identical with Dana 27, 30, etc.

When the Estate (P 220) is introduced during 1962 it comes with a rear axle from Salisbury with the ratio 4.55:1. Later during the manufacturing of the Estate (about 1965) Volvo starts buying rear axle drive units from one additional supplier, and this drive unit has the ratio 4.56:1. Both drive units are kept on stock under the same part number and are mounted randomly in the Salisbury axle latest up to and including model year 1968. The new Spicer 30 is mounted in the Estate during model year 1965 (from chassisnumber 26228) but only comes with the ratio 4.56:1. The practical difference between the ratios 4.55:1 and 4.56:1 is ofcourse limited, and Volvo has different data on what ratio the Estate had 1962 - 1968, for instance several sales brochures state 4.56:1 1962 - 1968 while mechanical shop literature state 4.55:1 1962 - 1967.

The Spicer 30 axle starts replacing the older Spicer 27 on the four door version (P 120) and two door version (P 130) from week 5 1966, still with the ratio 4.56:1 on cars with overdrive (some 122 S 1966 - 1967 and all 123 GT 1967 - 1968) and with 4.1:1 on all others. During model year 1967 (week 48 1966) Volvo starts mounting a their own version of Spicer 30 in the P 130 that they also produce themselves, mixed with Spicer and Hayes manufactured axles. This axle is called Volvo 1030, where 10 indicates Volvo, but is identical to Spicer 30 and Hayes when it comes to parts. The 1030 axle stuck around until the late 1980s on the 240- and 740-series (ofcourse with different suspension and brake equipment). With the model year 1969 the ratio is changed again in the Estate and on the few cars delivered with overdrive 1969 - 1970 (123 GT) when it is reduced to 4.3:1, the other cars keep 4.1:1 to the bitter end.

Simply put: P 120 with the B16 engine (1957 - 1961) has the rear axle ratio 4.56:1. P 120 and P 130 with the B18 engine (1962 - 1968) and overdrive transmission has the ratio 4.56:1 (including the 123 GT). P 120 and P 130 with the B18 or B20 (1962 - 1970) engines that do not have overdrive has the ratio 4.1:1. The few P 130 with the B20 engine and overdrive (only the 123 GT) produced 1969 - 1970 has the ratio 4.3:1. P 220 Estate 1962 - 1964 has the ratio 4.55:1. In 1965 - 1968 it's mixed 4.55:1 and 4.56:1. The last model year (1969) the P 220 gets the ratio 4.3:1.

Volvo Amazon was available with limited slip differential ("anti-spin") on the rear axle on all editions, but this was an option that the customer had to pay extra for. Volvo Amazon in Swedish Police edition has limited slip differential on all cars (P 120, P 130 and P 220). The 123 GT came with limited slip differential as standard equipment on some markets (not Sweden). See for instance this specification from a reseller in Canada (concerns 123 GT model year 1968 produced at the Halifax plant, type designation 133951P). Limited slip differential was sold as accessory by Volvo and can be retro-fitted.

* The ENV axle with stated ratio 4.1:1 actually has 45/11 (i.e. 4.09:1) but has been rounded off to 4.1:1 by Volvo. This lacks practical meaning, just like the Salisbury axle's 4.56:1 or 4.55:1.
** ENV was fitted in the P 120 up to chassis number 182155 (roughly half of model year 1965) and in the P 130 up to chassis number 149917 (early model year 1966).
*** The axles get a more stable attachment on the P 120 and P 130 from model year 1967 that does not fit on earlier model years.
**** P 220 in 122 S edition from model year 1963 (only on some markets, including USA).

Distributor

The distributors used in Volvo Amazon are all manufactured by Bosch, but have varied with different editions of engines.

* Replaced by 0 231 115 043.
** Replaced by 0 231 153 003.

Ignition Settings

The ignition order is 1-3-4-2 clockwise on the B16 engine and counter-clockwise on the B18 and B20 engines. There are different recomendations for the sport engines (B and D editions), but Volvo has been consistent on the A editions. The settings below are valid for an engine that has reached its working temperature, has the vacuum regulator disconnected (if present) and at 1,500 rpm, unless otherwise is indicated. Keep in mind that a lot has happened since these settings were defined by Volvo. The octane ratings (or rather the definition for them) have changed, the engine is worn, ignition parts have been changed over the years and a lot of other things that can affect the ignition settings. Don't be surprised if the ignition needs to be set according to other values than those listed here in order not to ignite too early (spike) or too late (excessive fuel consumption). Turn the distributor counter-clockwise for an earlier ignition and clockwise for a later ignition on the B16; the other way around for B18 and B20.

* With emission control.
** At maximum 850 rpm.
*** At 600 - 800 rpm.