Lucas C45 generator overview as applied for Jaguar XK120, 140 and 150
1. Generators (dynamos) in the pre-XK era
Very early SS Jaguars had Lucas C45YV/1 dynamos, until about 1937 SS Jaguar started using Lucas C45PV-3 generators for the 2½ and later 3½ Litre versions. These dynamos were also available as “Special Equipment” version (in addition to the more common “Standard” version). This is why many illustrations and photos from about 1934 onwards, show Jaguar engines with the typical “Special Equipment” generators having a nickel-plated yoke, black strap over the inspection holes for the brushes and (of course) the “Special Equipment” badge.
These first pre-war C45PV/3 dynamos for the larger engines had type number L1/1 and Lucas part number 238.186. Note that pre-war Lucas part numbers consisted of 6 digits.
The Jaguar “Spare Parts Catalogue” of December 1947 states that Jaguar (SS) 100 and other 3½ Litre models from 1938 onwards used the Lucas C45PV-3 generator (with Jaguar part no. C1075) having a cast iron pulley with integral fan (Jaguar part no. C1076); the latter was continued over many Jaguar models until 1954. We may therefore assume that also Mk IV and Mk V models have used this type of generator (to be confirmed).
2. The Special Equipment version of the C45 generator series.
From 1948 onwards Jaguar choose the “Special Equipment” version of the C45PV-4 model range with model number C45PVS, followed by C45PVS-5 and C45PVS-6, for the XK 120, 140 and 150. This generator is part of the C45 range, but there are (major) differences within the total range and parts are not always interchangeable.
Example early nickel-plated yoke with black strap.
The Lucas coding for the C45PVS generator model is composed as follows: generator with Concentrically mounted armature with 4.5” diameter yoke; Voltage control, 2-Pole system with long type yoke; Ventilated; optional Special finish, followed by an indication of design update (-4 or -5 or -6).
It is unclear whether the “Special Equipment” version of the C45PV-3 generator was ever coded PVS-3. There are reasons to believe that the “S” was only added when the C45PV-4 dynamo was introduced in 1948. Lucas emphasizes the higher position of the “Special Equipment” version by stating in their brochures that these “have generally been applied to High Speed Sports and other special cars”. They further supported the use of “Special Equipment” versions by giving it a unique, generic type number C45PVS (instead of C45PVS-4). Only with the introduction of its improved successor in 1953 they felt the need to introduce the type number suffix: C45PVS-5.
From 1945 onwards four main groups of C45 generators can be distinguished whereby the first 2 groups have been mentioned here for reference only:
1. C45P-4 and P-5 series: this is a fully closed, non-ventilated version with a cutting-in speed of 900 to 1050 rpm and a maximum output of 13 Amps at 1350 rpm. Mostly applied for agricultural use and used in combination with Control Boxes RF97 or RB107.
2. C45PV-4 series: this is an open, ventilated version with a maximum output of 20 Amps at 1650 rpm. Applied for automotive use where a load is not exceeding 17 Amps and to be used in combination with Control Boxes RF95 or RB106.
3. C45PV-5 and PVS-5 series: is basically similar to the C45PV-4 but with the ventilation considerably improved by increasing the size and shapes of the apertures in the commutator and driving end-brackets for all suffix 5 versions. “S” versions have ball-bearings at both shaft ends. These generators have a maximum output of 20 Amps at 1650 rpm . Applied for automotive use where the continuous load does not exceed 17 Amps and to be used in combination with Control Boxes RF95, RB106 or RB310.
4. C45PVS-6 series: an improved version of model C45PVS-5) with a.o. a new armature, commutator end-bracket and brushes. Output was now 25 Amps; to be used in combination with Control Boxes RB310 (updated version 37297A with higher Amps setting).
3. Survey and timeline of C45 “Special Equipment” generator versions per XK type
4. Lucas C45PVS models
This generation of Lucas generators has probably been introduced in 1947. Although the Lucas part number was 22429A from the beginning, the commercial Lucas type number was C45 ZV or C45 ZVH. This was a Special Equipment model, but with a different commutator end-bracket, here shown with a square housing for the roller bearing. Also note the different electrical connection with two plug type connectors instead of the later terminals. The examples shown below have date code 1 48 and 9 48 respectively. The type model changed to C45 PVS when a modified commutator end bracket was introduced (probably 1949) with part number 22429D.
Lucas 22429A had a separate square bearing housing and was never used on XK120
4.1. Lucas 22429D & E (Jaguar C2527/1)
Early XK 120s up to W5275 (1952) used Lucas generator model C45PVS, part number 22429D and 22429E. The same version was applied on early Mk 7’s up to engine # A8126. The C45PVS is a specially finished product with ball-bearings at both ends, a machined (non-passivated) nickel-plated yoke , a black painted band or strap for access to the brushes, commutator end-bracket in natural aluminium and drive end-bracket in cast iron painted black.
The “Special Equipment” tag is made of steel and nickel-plated with black-enamel depressed fields. It is secured by two bright steel solid rivets with hemi-sphere head; later 22429F and H versions had gloss-black rivets.
Later 22429F plate
This generator initially consisted of an armature part number 238806 with (metrical!) ball bearings at both ends. In the aluminium commutator end (C.E.) bracket (Lucas part 238845) a rubber sealed Hoffmann type 115 ball bearing was placed (dimensions Ø15 xØ35 x 11 and Lucas part 189307). This ball bearing is generally known as 6202. At the driving end a cast iron bracket (Lucas part 238796) is used with a rubber sealed Hoffmann type 117 ball bearing (dimensions Ø17 xØ40 x 12 and Lucas part 189308; also known as 6203).
Early C45PVS integrated pulley and fan as one casting (C1076).
Note: Lucas 22429 generators (from D to H) used a cast iron pulley with integral fan (Jaguar part no. C1076). (Note: reproduction versions are made nowadays in cast aluminium). The later 22462B generators had a different pulley (Jaguar part number C2579), while the successor types Lucas part 22462D and E had a separate aluminium pulley and fabricated steel fan (Jaguar part number C7427 and C7428 respectively).
Early C.E. bracket without Lucas script Example of C.E. bracket for 22462/D with Lucas script
Note: Early C.E. brackets (both part number 238845 and 239265) apparently have been casted without any Lucas script. Later brackets from generator part number 22462/D onwards have the word “Lucas” and “Made in England” on the outside. The inside casting numbers (L134), however, are identical for both versions.
Note: The commutator end-bracket for all “S” versions can be easily distinguished by having a larger recess for the ball bearing with an outer diameter of 35 mm; “non S” versions have a (smaller) bronze bush bearing with an outer diameter of 19,2 mm (Lucas part 238567 or 293263).
Different C.E. bracket for Special Equipment version (top)
4.2. Lucas 22429F & H (Jaguar C2527/1)
XK 120s manufactured in 1951 and till mid 1952 used Lucas dynamo model C45PVS with part number 22429F and H. The same version was applied on Mk 7s of that period. Some modifications were made compared to the earlier part 22429E.
Note: generator C45 PVS was not painted black Commutator End of Lucas 22429F
A new armature (239190) with ball bearings at both ends was introduced; this armature remained the same for the entire later production, including part number 22462 versions and changed only with the introduction of the C45PVS-6 model in May 1959.
Type plate Lucas 22429F (December 1950) Pulley and fan combined in one casting
A new aluminium commutator end-bracket (Lucas part 239265) was introduced with a different bearing type: a fully enclosed Hoffmann type 115P bearing was now used (dimensions Ø15 xØ35 x 11 and Lucas part number 189237). At the driving end nothing changed with bracket part 238796 and bearing part 189308. All other parts remained the same.
The photo below shows the same 22429 generator however with a K suffix as produced in 1957. This may have been a later service-part production run for the aforementioned types.
Lucas 22429K with built date 10 57
5. Lucas C45PVS-5 models
5.1. Lucas 22462A & B (Jaguar C5433)
In June 1952 an improved generator type was introduced for the XK 120 from engine number W5276 onwards. This version was initially coded Lucas 22462A and later with suffix B (Jaguar part number C5433). This is the new C45PVS-5 model which is largely identical to the preceding model apart from a new driving end-bracket (now part number 239012) which allows for better cooling of the generator. The bearing for this end-bracket, however, remained unchanged (Lucas part 189308). Apparently these “Special Equipment” versions were no longer nickel-plated and the yoke was (at least in case of the 22462B: see photo below) painted grey, as was the strap giving access to the brushes. At some moment (introduction of the 22462D version?) the yoke was painted in a black colour and remained black for all following versions of the C45PVS/5 model.
Some sources indicate that the 22462B was also applied on the early XK140. The Lucas “Advanced Information” data sheet for 1955 Jaguar Cars (dated February 1955) still mentions the 22462B as correct for the XK 140 (in fact for all 1955 Jaguar models). There is however no evidence that these (grey painted) generators have ever been used on XK 140s.
“Special Equipment” badge on 22462B generator painted grey (Lucas “poly-chromatic” grey?)
5.2. Lucas 22462D & E (Jaguar C5433)
With the introduction of the XK140 in 1954, the C45PVS-5 model was continued under part number 22462D, then later with suffix E. The differences between early 22462B and later versions with suffix D and E appear to relate to modifications in the two long fixing bolts which changed from part number 238521 to 272752 (see photo below right). The Jaguar code C5433 did not change although this modified generator was now painted black (both yoke and cover band) instead of grey.
Note: some sources mention that the E suffix generators don’t have a strap. This statement seems to be incorrect as there exist too many 22462E generators with that strap and the opening beneath (see photo below).
Lucas 22462E with opening for brushes
Part number 22462E was also applied for the XK 150 until May 1959 (up to engine V 1598) when a new generator model C45PVS-6 with part number 22496 B was introduced.
Note: although the specification of the generator remained unchanged, the oval brass “Special Equipment” badge was never used on the generators of the XK 140 nor XK 150.
6. Lucas C45PVS-6 models
6.1. Lucas 22496B to D (Jaguar C15255)
The model C45PVS-6 is an improved version of the 22462 (which was model C45PVS-5). Most parts remained the same, apart from a new armature (now part number 239511), a new commutator end-bracket (now 54210072) and brushes with their springs (54210090 and 54210091 respectively). Output was now 25 Amps. The C45PVS-6 was used on the later XK 150’s and on the 3.4 and 3.8 Mk II saloons in the 22496D version (not USA & Canada for which markets the C48 model was used).
Lucas C45PVS6 22496D (Courtesy Gary Seraphinoff)
7. Additional Service information
7.1. Old and new brush types
As mentioned above, the C45 PVS-6 used a new brush type (Lucas part 54210090) about ¼” thick whereas the brushes for the older versions (part 238240) are 5/16”. They are not interchangeable. The width of the brush is 1” and the height ¾”. A similar brush set (Lucas part 238061) is used on the older C45 types and has identical dimensions as per 238240. The length of the electrical connection wire, however, is only 58 mm (instead of 63 mm for the 238240) but still this older type might fit pre-C45PVS/6 generators .
Lucas brush set 238240 Lucas brush set 54210090
7.2. Sundry Parts Set Lucas 239024
For a total overhaul of the C45 generator, Lucas provided a “sundry parts set” containing all the smaller parts required. This kit (Lucas part number 239024) was used for the complete “Special Equipment” range covering 22429, 22462 and 22496 series generators. Occasionally these kits are offered (e.g. on Ebay), but as an alternative the description below provides input about what is required for a total overhaul.
The sundry parts set contains the following items:
- CSK screws (2) holding the field coils in the yoke
- Long rivets (3) for mounting the bearing plate over a new Drive End bearing
- Short rivets (4) securing the brush holders to the Commutator end plate.
- Small rivets for positioning the endplates to the yoke
- Woodruff keys (2); see special chapter below
- Brass nuts 0BA (or M6) and washers for the D-terminal post (2 of each)
- Steel nuts 2BA and washers for the F-terminal post (2 of each)
- Screws 4BA and lock washers (2 of each) for connecting the brush wires
- Felt washers (Ø35 and Ø40) for the (original “open”) bearings (see also chapter 7.3)
Content of Lucas Sundry Parts Set 239024
7.3. Original bearings:
The original bearings for Lucas C45PVS generators were supplied by Hoffmann, Made in England.
- Bearing 189237 Hoffmann 115P Fully enclosed
- Bearing 189307 Hoffmann 115 Rubber sealed
- Bearing 189308 Hoffmann 117 Rubber sealed
Note: the “Lucas 400-e catalogue“ describes Bearing 189237 as Ø17 xØ40 x 12, but this is incorrect and should read Ø15 xØ35 x 11 (given the correct Hoffmann’s code 115P).
Period Original Equipment bearings by Hoffmann, England
Bearing in end plate. No. 1 is bearing and no. 2 is felt ring.
7.4. Woodruff key:
The key used by Lucas for the pulley (and fan) is Woodruff key No 50 according BS46 with dimension 1/8 x 5/8″.
7.5. Shaft nut for pulley
Lucas part number for this special Nut is 160820 and fits only 17 mm shaft generators. It is a special thread often referred to as .668-20 meaning 0.668”(16.97 mm) and 20 TPI (1.27 mm pitch). Most likely, originally this was a M17 x 1.25 mm thread, but converted to “Imperial”.
Thrust spring Lucas 238954
7.6. Thrust spring Commutator End
To keep the lateral position of the armature fixed within the generator, Lucas used a (rather heavy) coil spring at the Commutator end bearing. This spring pushes the Ø 35 mm bearing in the direction of the Drive end. It is listed as Lucas part number 238954: very hard (if not impossible) to get, so an old one or a reproduced spring is required in case the old one can no longer be applied. Please note that the intended “lateral movement” of the bearing implies a “finger-press” fit of the bearing in the commutator end plate. If a hand or machine-press is required to install the bearing, the fit will be too tight and movement of the bearing will become impossible.
Note: Although this Thrust Spring is absolutely indispensable and unique to all “Special Equipment” versions (and is referred to in most illustrations in handbooks and manuals), it is not listed as part number in the “Lucas 400-E catalogue” for the versions C45PVS and C45PVS-5, nor in the Jaguar Service Parts lists. It was listed for the first time for the C45PVS-6 models as Lucas part number 238954.
7.7. Field coils
All C45PVS, C45PVS-5 and C45PVS-6 use the same Field coil with Lucas part no. 238820 (Jaguar code 2789). Although this Field Coil has also been used for other C45PV-5 generators of the “non-S” type, they are very difficult to find (if at all). The nominal resistance for the set of coils is 6 Ohm, although a value of 5.5 Ohm (or roughly a minus 10% tolerance) doesn’t seem to affect the generator output (as experience learned). As the output current of the generator might increase over the years the use of the RB106 or RB310 Control Box (with current control) is required.
Field coils 238820 for all XK generators
Two brass terminal connections are used for connecting the generator. The F-terminal is the smaller one suited for eyelets with a 3/16”(4.8 mm) inner diameter and is fixed to the yoke by a rivet . The electrical wiring connection is secured by two 2BA nuts, one of them acting as a locking devise. Below is a photo of a replacement F-terminal (Lucas part number 227625) as can sometimes still be found.