X-Mozilla-Keys:                                                                                 
Brian D. Cain wrote:

Righto'.  I wasn't going to say anything, Bruce, because I knew you'd
come back.  =)

Some of the differences, James, between the earlier 13B's and the
latter 13B's (86-88, 89 and up) include things such as:

- Factory hardened stationary gears
- Increase casting thickness around the upper (driver's side if you're me)
  tubular dowel pin at the rear iron/end plate
- Lighter rotors that presumably use less iron and more aluminum, losing
  around ~2lbs
- 10x stronger corner seal spring (it's actually a spring and not a piece of
   wire)
- Stronger side seal springs
- A different style of rotor housing inner-wall coating
- Change in port sizing, especially on the Cosmo 13BT and 20BTT
  engines
- Higher oil pressure regulation

That's what I can think of off the top of my head.  I would say they're
quite
desirable, but the 93+ engines are mounted via the rear iron housing
instead of the intermediate, center end-plate.

B

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