is the speeder for lapping in valves ?
I'd concur, it looks like it would be intended for valve lapping on large truck, and medium size stationary, engines The valve heads were provided with a pair of shallow holes to be driven by such a tool. Alternatively, some valve makers provided a slot to be driven with a tool resembling a large screw driver.
I'd suspect that small wrench to be a 'special', for two specific uses, possibly on some variety of small engine.
cheers
Carla
Or an alternative 1/2-inch drive attachment. Here's a Blackhawk T-11 (neither photo very good, sorry) of that type originally provided with several Q.D. wrench sets...Alternatively, some valve makers provided a slot to be driven with a tool resembling a large screw driver.
As Carla pointed out above, in an earlier time many valves had two pockets drilled in the top of the head. These pockets provided spots for the tabs of the tool to engage the valve to turn it while lapping it in.
This has nothing to do with installing or removing valve guides.
It is possible that the tool in question was used to turn something else, like a flush screw-in cap, but the same process is involved - pockets to provide a grip on the part and protrusions on the tool to engage those pockets.
