The head gasket evolution as I know it.
The first one was E1ADKN-6051. From early 53 (and I just can't find a serial no. for it) E1ADKN-6051B replaced the original gasket. Both of these were copper asbestos but don't really know the difference. From the fitting of the engine to the Thames ET6 many changes occurred, the petrol engine had the compression ratio increased to 6 to 1 for the lorry by using TVO parts (piston rings and liner mainly) to give higher displacement (also featured on 563E industrial engines). Tractors remained at 5.5 to 1 and used the same head, with E1ADKN-6051B. Then from 1425097 the steel gasket (E1ADDN-6051B) replaced the previous E1ADKN-6051B on diesel engines. The Mk2 types have a new bypass hole and a slightly different rear end. The petrol compression ratio remained unchanged but used two gaskets E1ADN-6051 and a spacer E6-CA-9 between them (not too clear about this, if anyone has more information it'll help get this right); the gasket also became steel (E1ADKN-6051C) on lorries (this one would be replaced by 528E-6051 but I've found no full reference to this), their compression ratio increased to 6.4 to 1 with all petrol parts. At the same time the 6 cylinder engine appeared, the original gaskets being 508E-6051 and 510E-6051 (both steel). From 1481091 the petrol compression ratio was changed to 5.84 to 1 on tractors with gaskets E1ADN-6051 and new spacer E7-CA-9, the lorry remained unchanged (the new parts were offered for Mk2 engines as well). From 530E-8596 and 510E-15970 a crimp was added on the LH side to improve sealing (I can't find any other reference to it). From 1518654 a new Copper asbestos permanite gasket (E1ADDN-6051C) was fitted to solve the issues with the steel gasket. This coincided wit the large diameter spigot liners and the new locating dowels (these dowels were actually always fitted to 6 cylinder engines). At the same time 510E-6051B catered for the same change in the 6 cylinder engine. For service E1ADDN-6051D and (510E-6051C) were provided for engines originally fitted with the steel gasket. Finally from 1565580 the final composition gasket was fitted (E1ADDN-6051E), together with smaller diameter spigot liners. This change also happened on the 6 cylinder engine, being 510E-6051D. When the twin o-ring liner appeared petrol lorry gaskets became thin composition too with 528E-6051B and 508E-6051B from 500E-59396, 528E-23449 and 508E-66110. In 1962 with the introduction of the Mk2 Trader the 6 cylinder engine was fitted with 510E-6051E which replaced the previous gasket to provide more space for thicker push rods used on lorries from then on. I'm not sure what was done to petrol engines but the parts book quotes 953E-6051 for zero octane use (and presumably TVO engines for service). Ebro probably started with the steel gasket then followed a similar evolution but went onto their own S1ADDN-6051C still with flat liners. They carried on with flat liners and put a composition gasket on in 66 or so (S1ADDN-6051D). The last number I've found is S1ADDN-6051F, it looks like another steel gasket but don't really know, there's very poor information on this and no idea how many changes occurred.
Now for a table (missing details will be filled in as they're clarified, Ebro serial numbers are not at all clear yet so for now won't appear, Mk1 industrials (954E, 955E, 956E, 562E & 563E) are also similarly unclear as are many lorry numbers, especially ET6's):
Part no. _________________________ use
E1ADKN-6051 _________________ 1217101-Early 53
E1ADKN-6051B ________________ Early 53-1425097, 502E-0001-502E-46802 & 500E-0001-500E-46803
E1ADDN-6051B ________________ 1425097-1518654, 502E-46804-502E-54552, 530E-0001-530E-12714 & S0001-(between S160725 and S162216)
508E-6051 ____________________ 508E-0001-508E-66110 & S0001-(between S221604 and S225057) Equivalent to 1425097-1591023
510E-6051 ____________________ 510E-0001-510E-29237 & S0001-(between S160725 and S162216) Equivalent to 1425097-1518654
E1ADN-6051 __________________ 1481091- & S0001-
E1ADKN-6051C ________________ 500E-46803-, 528E-0001- & S0001-
528E-6051 ____________________ 500E-500E-59396, 528E-528E-23449 & S-(between S221604 and S225057)
E1ADDN-6051C ________________ 1518654-1565580,502E-54552-502E-58003, 530E-12714-530E-19344 &
____________________________________________________________________________(between S160725 and S162216)-aprox S200000
510E-6051B ___________________ 510E-29237-510E-55917 & (between S160725 and S162216)-aprox S200000 Equivalent to
_____________________________________________________________________________________________1518654-1565580
E1ADDN-6051D ________________ Service for E1ADDN-6051B
510E-6051C ___________________ Service for 510E-6051
E1ADDN-6051E ________________ 1565580-08D-976148, 502E-58003-, 530E-19344-, 624EB-0001- & aprox S200000-approx S752487,
__________________________________________________________________Ebro made until approx S900000, don't know if this was used
510E-6051D ___________________ 510E-55917-aprox 510EB-100000 & aprox S200000-approx S272345 Equivalent to 1565580-(08C-960337)
528E-6051B ___________________ 500E-59396-500E-, 528E-23449-528E-, 622EB-0001- & (between S221604 and S225057)-approx S752487
508E-6051B ___________________ 508E-66110-508E-, 658EB-0001- & (between S221604 and S225057)-approx S616139
_________________________________________________________________________________________ Equivalent to 1591023-(08D-976148)
510E-6051E ___________________ aprox 510EB-100000-, 660EB-0001- & aprox S272345-approx S616139 Equivalent to (08C-960337)-(08D-976148)
953E-6051 ____________________ Service on zero octane and TVO
S1ADDN-6051C ________________ Early Ebro production
S1ADDN-6051D ________________ Mid Ebro production
S1ADDN-6051F ________________ Late Ebro production
And now for pics (please add any you can, lorry and industrial engines are also):
E1ADKN-6051
E1ADKN-6051B
E1ADDN-6051B
E1ADKN-6051C
E1ADN-6051
508E-6051
510E-6051
528E-6051
E1ADDN-6051C
510E-6051B
E1ADDN-6051D
510E-6051C
E1ADDN-6051E
510E-6051D
528E-6051B
508E-6051B
510E-6051D
953E-6051
S1ADDN-6051C Super Billy's gasket just after removal, will get better pics when I can
S1ADDN-6051D
S1ADDN-6051F
Note the post is unfinished as I only have access to our vehicles, therefore your help with pics of the other heads is highly appreciated. I have seen some on Ebay, causing some doubts on where the part no. and EnFo (or FoMoCo) are stamped. Also Ebro parts are rather more difficult to keep track of with no proper manuals around.
Note at the time of posting I don't yet have good pics of our ones, they will come shortly.
Sandy
