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| Joined: | 03-12-2005 |
| Location: | Kingman, Arizona USA |
| Posts: | 532 |
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JH P/N 94097 - Lotus P/N unknown - 0.001,5" thick - color red
JH P/N 94098 - Lotus P/N unknown - 0.002,0" thick - color yellow
JH P/N 94099 - Lotus P/N unknown - 0.003,0" thick - color royal blue
JH P/N 94100 - Lotus P/N unknown - 0.004,0" thick - color black
Furthermore, under P/N 93545, Delta supplies a red gasket associated with Lotus P/N A907E0474Z. Somewhere along the way I gathered the impression that this was the only gasket still available -- but of course I could be wrong. All of the gaskets I've actually seen have been red and very slightly more than 0.004,0" thick. This includes the one in my car's engine when I bought it (known to be a replacement at some time in the car's past), the one in the engine I bought from Kurt Housh, and all of the ones I've ordered from Delta over the years.
To further confuse the issue: while looking into this, I found that Lotus has changed several critical oil pump specs. Comparing the JH shop manual to an unnumbered Lotus tech data pamphlet datestamped April 1987, we have:
Clearance between tips of rotor (inner gear) and annulus (outer gear): JH 0.006" max; Lotus 0.002" min, 0.006" max.
Annulus end float: JH 0.000,5" min, 0.001,5" max; Lotus 0.001" min, 0.003" max.
Rotor end float: JH 0.000,5" min, 0.001,5" max; Lotus 0.002,5" min, 0.003,5: max.
Annulus rim to housing clearance: JH 0.001" min, 0.003" max; Lotus 0.007" min, 0.012" max.
In this regard I'll note that most of the rotor gears I've seen were very slightly thinner than the annulus gears, and the Lotus rotor end float spec may be nothing more than official recognition of this situation. The Lotus annulus end float seems a bit high to me, and I'd be worried about pump priming in a well worn engine. I don't know wny the annulus rim to housing clearance specification was changed so much, but it's been my experience that it isn't a particularly critical dimension. Others with greater experience in these areas may well have different opinions.
Since no rotor and annulus part numbers are provided, it seems reasonable to expect these revised specs to apply to the JH too -- certainly if any parts have been replaced with non-vintage ones. With that in mind, I'll note that Lotus also revised the minimum oil pressure spec (hot engine) as follows:
Idle, 5 psi minimum; 3500 rpm, 35 psi minimum; 6500 rpm, 45 psi minimum.
I guess this means that if you have 45 psi at 6500 rpm, the engine will survive the warranty period. After that...?