Installing heads with rockers/cam installed

[RogueEngineer]

I had to tear down an recent engine rebuild with only 250 miles due to an intermediate shaft gear failure. Could have been much worse! Somehow the gear didn't completely disintegrate so I didn't lose oil pressure or cam timing.

I unbolted the cam towers and cylinder heads as one unit, and would like to reinstall without removing all the rockers/shafts.

Is there a strategy/process for doing this?

Bonus: Pic of failed intermediate shaft gear.

[HaroldMHedge]

Ouch

Curious how many miles are on that gear and how does the crankshaft gear look?

There have been several threads recently that address your question of head installation as an assembly.

Fitting the heads
Installing heads with cam tower

[RogueEngineer]

The odometer said 260k miles before rebuild. Backlash was in spec, and I don't recall any visual indicators of damage prior to installation.

The steel crankshaft gear looks 100% fine. New gear checks out with perfect backlash - Fluctuating between about .0008" and .0017" when checked at 4 points (90 degrees-ish) and two crank rotations.

Perhaps I damaged it when pressing on new sprockets to the shaft. Hard to say.

Thanks for the links!

[HaroldMHedge]

Thanks

I'm in the process of rebuilding my 3.2L with 140K on it. Upon initial inspection my aluminum intermediate shaft gear looked good, backlash and the diameter were fine. Following a good cleaning I noted that the gear had some pitting so I'm replacing the gear to avoid a potential failure like yours.

[Flat6pac]

From Z1 back the crank down about 30 degrees and all pistons are inside the case so you don’t have valves open to be a crush concern.
Bruce