Greetings.

We are working out the bearing clearances for the mains and rods for an Evo 6. The crank is used, but polished. The rods are non-machined Oliver rods.

We installed S0 bearings in the case and rods and took the parts to a helpful machinist to measure exact numbers with his precision instruments:

Mains:
0.07 mm / 0.0028 in

Rods:
0.08-0.09 mm / 0.0031-0.0035

Based on forum researches, the preferred clearances are closer to 0.0020 - 0.0025...for a 400 HP street car.

Our question: what are the increments for the factory bearing offerings - S0, S1, S2, S3, and S4?

We've seen a reference to 0.0075 mm / 0.003 in between the rod bearings offerings, but not definitive.

Thanks for any inputs!

 

Tip from the forums pointed us toward the Evo 6 factory manual - thickness of the rod shells:

0 1.483 – 1.487
1 1.487 – 1.491
2 1.491 – 1.495

Which extrapolated, the thickness between 0 and 2 is 0.008 for each shell...since two = 0.016. This would decrease the rod bearing clearance to 0.074 which seems still on the high side, but below our threshold before going another direction.

The mains appear to be similar in sizing and can easily update to 0.0625 using the S1 bearing which is perfect, it would seem. Hate to buy another set of bearings, but closer to the target and much more confidence in spinning it to redline!

Thanks!