How often to run the engine in a Centurion?

[Perry Kitson]

I picked up this method from some old timers in the antique car hobby. I would do an oil change in the fall before putting the machine away for the winter. Then, with the engine"cold", lightly pour 10W oil into the carb as it idled, until it produced a nice smoke cloud for a 5-10 seconds, then shutting down the engine while still adding oil. This gets the oil onto both intake and exhaust valve stems, as well as the top end of the cylinder. Doing this with a cold engine, at an idle, does not give complete combustion, so does not end up with an appreciable carbon build up, as well as having more clearance before things heat up. Of coarse, pulling the plugs and adding some oil to the cylinders is good as well, it does not get oil onto the valves, but this is not a big concern for overhead valve engines.

[45jim]

When we restored our Centurion in Calgary (now in Edmonton and still going strong) we asked the very question of our old hats. You see regular army vehicles sit a long time in open storage between exercises and on deployments the vehicles are left with a skeleton crew and often go untouched for 6 months or more. Our museum vehicles would be no different.

In fact, when the Strathconas had Centurions most were kept in Wainwright while Regiment was in Calgary (about 4 hours away). A team in Wainwright performed needed maintenance but the tanks mostly sat for 8 months a year!

In the museum, we found the old maintenance logs and they stated that tanks prior to storage were to be "prepared". This perpetration included full maintenance, oil changes and greasing or oiling of all moving parts. Engines (including the aux engine) were to be run until operating temperature was reached and if the tank was mobile, it was to be driven approximately 5 miles. After parking they were allowed to idle for 5 mins and then shut down. The next morning the plugs were removed and 3 teaspoons of 10wt oil was added to each cylinder and the engine spun to distribute the oil and plugs reinstalled. If the engine was not to be run for up to 1 year or more desicator plugs would be installed in the spark plug holes. I was told no one ever saw a desicator plug during their service.

[jdmcm]

Would installing a block heater be useful? When I had my trucking company it was common to "plug" trucks in after they had sat for extended periods, even in the milder BC weather. If a truck had major engine work such as in an in-frame rebuild or god forbid a full out of frame rebuild, that truck never got started during break in until it was plugged in for several hours, preferably overnight...the big Detroits, 12V-71's were fitted with aftermarket pre-lubers from Luberfiner, this allowed you to push a button and watch the oil pressure from in the cab reach a certain point before you tried starting...much like the Russian/Soviet era tanks...might be cheap insurance compared to rebuilding a meteor? Should be a pretty easy installation in a vehicle with an external oil tank, and I believe Malcolm said the main fuel tanks were not currently installed...should give you plenty of room

[eddy8men]

they don't like being left outside, the biggest problem i've had with cents is the clutch plates sticking/dragging, i also had this on the cromwell. you can either hold the clutch pedal depressed when stored, which i'm not keen on or make sure it's bone dry before it goes away for the winter. if the clutch does stick a good hose down with a steam cleaner will free it evereytime.
the meteor can be easily turned manaully if you want to avoid running it. on top of the starter motor you'll find a 7/16th hex bar turn it clockwise and this will turn the engine over (slowly)

[Malcolm Towrie]

Jeez, you guys are good!
Eddy, I rebuilt the clutch about 3 years go with the best parts from 2 used clutches we had and then went onto another project. But I covered the clutch up well, so when we checked the clutch recently, it still spun freely when disengaged, despite outside storage.

jdm, a preoiler, like our T54 has, would be great. Wonder how easy that is to install? But you know, considering we will run this Cent about 50 miles a year at the most, it's unlikely we will see any problems from bearing or bore wear in my lifetime!

45jim, great info! Now the question is do we do it the easy way and pour light oil into the cylinders through the carbs while idling like Perry says, or do we pull the intake side plugs and squirt the oil in? I kind of like Perry's way because it is easy, and also it gets oil on the valve stems to some extent.

Malcolm

[eddy8men]

malcolm i wouldn't over think it. cents are pretty squaddie proof and as long as they are stored inside i doubt you'll have any issues

[45jim]

The air intake horn location and the updraft carb of the Centurion may make it difficult to get the oil into the cylinders as you really can't pour from above with the engine running. You might be able to rig up a curved tube and follow Perry's method, it may work as well if not better than just oiling the cylinders. It just might be physically impossible for the engine to draw the oil up through the carb.