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 Posted: 02-13-2020 05:27 pm
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Esprit2

 

Joined: 05-01-2005
Location: Minneapolis, Minnesota USA
Posts: 460
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discogodfather wrote:
Just picked up on this difference after re-reading Tim's explanation- there is a black metal ring on the bottom of the floor of the distributor housing. It's not much of a seal though, it looks to be worn well in.All Lucas distributors have a rubber O-ring around the outside of the long, slender shaft housing, where it slips into the engine. ONLY the Lotus/ J-H distributors have an internal rubber lip seal.

The standard Lucas distributor has steel bushings for the shaft, one at each end of the long shaft housing. The top one is pushed in flush with the surrounding floor of the upper 'head' part of the housing.

If a seal is present, then the upper bushing was simply pushed about 4-5 mm deeper into the housing to make room for the rubber seal. Then the seal was pushed in until flush with the surrounding floor... or a wee bit below flush.

If you see a rubber seal, then the distributor is configured for a Lotus/ J-H engine. If you see the edge of a steel bushing, then it's not.

The spiral on the shaft is there to act as a 'pump' to keep oil from migrating toward the head of the distributor. It's effective when the distributor is mounted vertically, or nearly so. However, it's NOT effective when the distributor is mounted horizontally, and oil will leak out via the head of the distributor. So Lucas added the rubber lip seal specifically for Lotus/ J-h applications... no others.

In North America, Delta Motorsports, JAE, and Dave Bean Engineering all stock the seal for Lucas' Lotus/ J-H distributors. The same seal also fits the Pertronix and 123 distributors that are close clones of Lucas.

Source: GACO IND49248 (Lucas OEM Seal).
Source: Chicago Rawhide CR4912 (exact replacement).
Source: Transcom TCM 13x19x3VG (nearest metric size).
Source: McMaster-Carr 9505K17 (different seal style... but works).

In the GACO IND49248 part number, IN = INternal, and D = Distributor. It's made for the purpose.

GACO Seals Website: https://gacoseals.co.uk/
GACO Seals Directory: https://gacoseals.co.uk/gaco-special-oil-seals-directory.html
GACO = George Angus & COmpany (Oil Seals).

Regards,
Tim Engel

Last edited on 02-13-2020 05:29 pm by Esprit2