Polini case build

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I used a press to mount FAG bearings to a Eurocylindro AV10 crank so we'll start from there. you can also use the hot / cold trick for mounting the bearings on the crank, but the fit was too tight on this crank ( the same with the Doppler Endurance crankI put bearings on) so I used a press because I had access to one. A press gives you a lot more control over the final bearing position, but make sure you shim between the crank cheeks or you will probably ruin your crank.

  • Place the crank and oil seals in the freezer.


  • Place the case halves in the oven at 250 F


  • wait 20 minutes (I drank a beer and watched an episode of 30 Rock online)


  • Take out one case half and one seal, press seal into case with a socket of the same diameter (or use your stock variator puller which is what I did) and a rubber mallet.


  • When seal is completely and uniformly seated, put the case half back in the oven.


  • Repeat with the other case half


  • wait 10 minutes


  • take the crank out of the freezer and one case half and slide the case half onto the crank (make sure it's the correct case half on the correct side of the crank and that the conrod is coming up through the case/cylinder interface and not the intake) if you need to, tap a little with a deep socked over the crank to make sure the bearing is completely and uniformly seated in the case.


  • return to freezer, wait ten minutes


  • repeat with other case half


  • I used SS 70mm long M6 socket cap screws and SS M6 A2 Nyloc lock nuts to secure the case (6 of each and 12 SS M6 washers)

For the version of this case that doesn't come with bearings or studs, the bottom end threads are different than a stock av10 case. Instead of 7x1.25 it uses 7x1.0 thread pitch at the bottom. You can flip the studs over from an av10 but finding 7x1.25 nuts might be difficult. I used 7x1.0 threaded studs on both ends by 130mm length and they worked just fine.