DIRTY STUFF

I PICKED UP THE FRESHLY PAINTED HARMONIC BALANCER TO SLIDE IT INTO PLACE ON THE NOSE OF THE CRANKSHAFT. GOT IT HALFWAY ON, AND IT STUCK!

WILLIAM PORKER

RESTORING old cars can be a long and often painful happening, and I have put in half a year so far on a mate’s 1952 Daimler Conquest Century sedan.

This is a proper gentleman’s carriage, built before Jaguar absorbed the long-time British manufacturer after they went broke. It’s got full leather upholstery and a weird pre-selector transmission – popular before somebody invented the familiar slushbox – and strange drum brakes that are hydraulic up front but work through mechanical rods to also pull on cylinders at the rear. They called them hydromechanical brakes by Girling, and if you need to brake in a panic, the front wheels lock up and the rear says: “Do you really want me to do something?”

Never mind. So far on this old street machine, I have rebuilt the six-pot pushrod engine with its alloy head and strong-as-an-ox bottom end, buying new pistons out of JP Engineering in Adelaide (who just happened to be casting up a new bunch when I rang), and making seven alloy spacer plates to fit underneath the rocker posts.

This was needed because some nong in a past year decided to mill at least 3mm off the head-face to raise the compression ratio, and compounded that by refitting the head on top of a thin factory steel shim gasket.

The immediate result was that they ran out of rocker screw adjustment, to the stage where to get the 13thou running clearance, the tubesteel pushrod cups were hammering into the undersides of the forged steel rocker arms.

We dropped the newly surfaced head onto the block, and couldn’t get clearance on three of the valves because the head was down that little bit more. A-ha, I said, we’ll just cut shim pieces out of this 3mm alloy plate – which I had successfully done before on other race engines – and wind the rocker arm screws down to take up the difference.

Didn’t work, did it? The pushrods had hammered so hard into the rockers where these screws came through that it was impossible on most of the rocker arms to screw these vital pieces down past where the thread ended.

Oh shit! We tried brute force and heat and nothing worked, so I went home and thought about the situation.

It was about two in the morning when my subconscious provided an answer. “Mate,” I said to Brian, “we just need to fit thinner shims.

That will lower the entire rocker assembly, so we don’t have to take these adjusting screws down so far, and we should get our 13thou clearance without the screws jamming.” Tried that, then checked every valve with feeler gauges. This shim revision worked beautifully and got us out of a nasty situation.

Then we had another problem. This engine had been hot-rodded by Daimler’s engineers, as their board demanded they produce 100 horses out of this 2.5L cast-iron-block straight-six by fitting larger valves, raising the compression ratio, adding twin 45mm SU carbs and free-flow exhaust manifolds, plus a half-race cam. This lifted the valves so high they had to pocket the block or rip the heads off the valves. To control vibrations common to six-cylinder cranks, they added an oversized harmonic balancer up front.

Now the owner of this carriage rightly insists on having everything painted so the car will look like new again when it finally gets back on the road, so he sent this balancer out with other engine-related stuff to be professionally finished in two-pack black.

That was fine, until I picked up the shiny-paint balancer to slide it into place on the nose of the crankshaft. Got it halfway on, and it stuck.

Thumped it with a soft hammer, which moved it another 6mm, applied gentle heat and gained another 10mm. Then it seized solid, and I couldn’t get the damn thing back off again.

Went home that night and came back with a selection of pullers, but none would fit, so I drove to a tool supplier, who first tried to sell us the regulation kit to fit Holdens and Fords, until I beat the young bloke about the head so he finally understood what I wanted. Then he led me to a shelf where this heavyweight puller was sitting; it was all of $80 and big enough to grab the rim of this jammed-tight Daimler bit.

Back to where the almost-rebuilt engine was sitting, we applied severe force through this puller, and the harmonic balancer got a real fright and almost fell off. I was having a problem trying to figure out why it was so tight on the crankshaft nose, until I looked inside the bore and realised that the painters had not only blown a coating of hard-as-nails two-pack over the outside of the unit, they had also carefully painted all the way up into the hole. The few microns of this paint layer had rolled back as I thumped the balancer on, enough to stop all progress. So when Brian carefully cleaned all that back to shiny metal, the mongrel thing just slid on as it should.

I will never fit a newly painted piece like this again without first looking down into that fundamental orifice! s

I PICKED UP THE FRESHLY PAINTED HARMONIC BALANCER TO SLIDE IT INTO PLACE ON THE NOSE OF THE CRANKSHAFT. GOT IT HALFWAY ON, AND IT STUCK!