Aligning Centurion engine to gearbox

[Malcolm Towrie]

I installed a nice 12 volt oil priming pump today and got 15 psi at the pressure regulating valve where the oil enters the engine. That should be enough to prime the crank bearings and fill the passages up to the cams and valves before cranking.

Headlights are installed and working and the front and rear sidelights are in progress.

The gearbox and final drives are reassembled with the new seals. We've got to clean up and repaint the gearbox compartment and the gearbox before installation.

The two ammo ready-racks have been overhauled and are ready for installation. These hold two shells each, are located beside the loaders seat, and run on rails over a limited part of the turret ring, presumably for the convenience of the loader when he is scrambling for fresh loads, especially under the floor plates.

Much to my relief, we managed to get a voltage regulator for the main engine generator from Tim Vibert in Australia for a good price. He has a lot of parts for Centurions. I needed this to charge the batteries because ours went missing and we don't plan on installing the auxiliary engine/generator for a while.

Malcolm

[Malcolm Towrie]

The Cent got driven around the arena many times today to train some people to drive her. Good news - the new gearbox and final drive oil seals didn't leak. Bad news - one of the rads is quite badly plugged so she's running a bit hot. We have spare rads but they need repaired. It would be boring if she ran perfectly, I guess.

A personal comment on driving these tanks: the increasing turn radius in higher gears is a given for this design but isn't impressive. Even second gear requires quite a large radius. So these tanks were not that maneuverable in my opinion, and hard work for the driver who's busy shifting to deal with varying terrain and corner radii. For tight maneuvering, first gear or neutral steering is required.

I haven't heard this criticism applied to Centurions so maybe I'm too harsh here? But it must have been so much easier for the later Chieftain drivers who had the same gear ratio to turn diameter limitations, but a transmission that was so much easier to select up and down.

Malcolm

[Malcolm Towrie]

Update: regarding the running a bit hot on a hot day, we repaired a spare rad that had clean fins and tubes but had a bad tube leak due to freezing (I think) to replace the one that I thought was plugged with oil and dirt deep in the core. But on further inspection of the supposedly plugged one, I’m not sure that’s the case. So what else would cause a Meteor to overheat on hot days?
When we bench tested the engine, the thermostat opened around 175 deg F so I don’t think that is the problem.
Running lean? I’ve got a wide band O2 sensor so I can check the air fuel mixture under load on both banks since ihere is a welded boss for the O2 sensor on both exhaust pipes. Damn, I hope it’s not a carb problem since they are a bitch to get access too.
Maybe a restrictive strainer mesh in the long range fuel tank we are using as our supply? Or low fuel pressure at high load?
Due to COVID, we haven’t run the tank for any length of time for more than a year, but with a potential Tank Day coming up in August, I’d like to get this resolved.
Malcolm

[Malcolm Towrie]

On another issue, when I select non-STAB mode, which provides power traverse, and only manual elevation (as it’s supposed to), the turret correctly rotates at a speed and direction depending on how the gunner’s or commander’s controller is rotated, as it should.
But when I select STAB mode, which is supposed to take signals from the traverse and elevation gyros to provide full stabilization for the gun elevation and the turret traverse, only stabilization for the gun elevation works (which is very cool, watching the gun stay level as the tank drives over berms), but the traverse stabilization doesn’t work at all, either from the stabilizing signal or the controller signal.
I know it’s a 70 year old tank and I can’t expect perfection, but it bugs me!
Malcolm