i fit the pinion-shaft hand tight only to make sure the taper is seated.
now, with this build i was investigating the use of a late-evo pinion bearing.
my thoughts are that a longer-roller bearing will be better than the shorter rollers as used in shovels.
i have previously sized the rollers and concluded what i neede to do to obtain the necessry clearance.
but i was concerned about the overall 'length' of the bearing, it looked like it would be too long when i was measuring rollers.
not i can investigate properly.
TnO flywheels are machined as early to mid 80s flywheels and have a small shoulder machined into the pinion side to accept a thrustwasher.
shovels typically have a 0.070" thrust washer either side of teh bearing cages, but evo bearings are used without thrustwashers.
you have to simply determine what will work, if it infact will?
the pinion-shaft mounted into the flywheel sits proud of the shoulder, it doesn't sit flush.
the amount it's proud i guess is determined by the machining of the tapers?
nothing concerning, just somehitng inevtible whem matching parts from different manufacturers?
so, if i place the evo bearing simply over the shaft, the rollers will overhang the pinion race, somehting i do not want.
i must place the bearing so the rollers are centralised as best as possible on the pinion-race.
here you can see the rollers would sit low and overhang at the base of the pinion-shaft.
not ideal.
if i place a 0.070" thrust washer under the bearing, it centralise it nicely on the pinion race.
but the problem with doing this, is that it doesn't leave enough clearance to get the retaining-clip in the groove.
the retaining-clip used with evo-bearings has a wider O.D than sovel clips to retain the bearing.
shovel clips can't be used, unless a thrust-washer is used to retian the bearing.
it looks like the evo-bearing can't be used in this build, which is a shame as i wanted to give ot a go.
on a different combination of pinion-flywheel-taper, the shaft might sit higher and allow it to be used.
i worked out that i'd need a maximum of 0.040 to 0.045" thrust washer under the bearing to allow the retaining-clip to be used.
this would place the rollers dangerously close to the edge of the race i.m.o, not something i want to do.
i know guys that have done this, numerous times, so it is possible, just not in this case?
come the time i will simply fit shovel cages and rollers, we all know they work,
i just wanted to expand my knowledge and try somehting different. you can still get OEM evo bearings and i'd rather use those in a bottom end rather than the potential poor quality third party parts. especially in somehting as importatnt as this.
i have some NOS OEM cages and rollers that i sourced for this build, as a backup incase this evo lark didn't work out.
so anyway, canned the evo gubbins and fitted shovel rollers for the mock assembly.
fitted the conrods, pistons with top-ring fitted and slipped over the cylinders.
i now have an assembly i can check clearances.
rotating assembly fitted in case-half to expose workings.
under the pistons are 'delrin' plates i made to slip over the base studs and stop the rods clashing against the case-wall and pistons aganst case-tops.