Building crank into Crankcases B44 and earlier

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kommando
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Building crank into Crankcases B44 and earlier

Post by kommando » Sun Nov 28, 2010 8:14 pm

My process is as follows, note that it is not std so entails some risk.

1. Check removed bearing for markings, drive side should be C3, timing side ball could be C3 or C4.

2. Buy 2 NF305E bearings to match the fits of orginals, if there was a V4 on the timing side this is not a C4 but a vibration code, so use a C3 on that bearing. The E identifies the roller bearings as Extra capacity which Norton called superblend. The roller have an edge radius and the roller corners do not dig in.

3. Relieve crank main bearing journals so that the main bearing inner rings are a tight sliding fit.

4. Install frozen roller outers in hot crankcases.

5. Install crank in cases and button up.

6. Check end float, due to using 2 rollers with no ball interfering you will be able to move the crank in and out easily.

7. Install shims to limit end float to 3-5 thou and to put rod in center of cases.

Have done this mod to several engines so far with no problems, using 2 E rollers gives the B44 more main bearing capacity than the B50 (unless you install 2 E's in a B50 ) . The lack of the retention of a ball is not an issue, there are 10's of thousands of Norton twin engines running 2 rollers with no control of endfloat but shims. Both bearing inner rings are locked to the crank when the crankshaft end nuts are installed and torqued.

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