The perils of painting a Bolt Head


This is possibly the most work you could do when deciding to paint the valve cover fixing bolts.

When last reviewed, I mentioned some changes to my A-H100 to make it more concours acceptable. Upon examining the engine bay, the two fixings that hold the valve cover in place were painted dk. blue engine color, rather than the gold color of the valve cover. So, I removed the bolts (British-set pins) to paint them the proper gold color. Upon removing the valve cover itself I discovered a milky white substance coating the interior area. This usually implies water and oil mixing…ugg! Blown head gasket being the most common cause. Old Healeys are noted for that feature, and many have been replaced with $5000 aluminum heads which seem to solve the problem. Often throwing money at a car solves issues.

Not convinced that the issue was a blown head gasket on a car with barely 100 miles since a complete rebuild, I removed the head, examined the head gasket and sent the head off to a machine shop for testing. Results showed no cracked head; pressure tested-it passed, but machinist shaved .003″ off the surface to make it flat. Mind you, this was flat 7 years ago when assembled. Car never overheated.

OK, if not the head, or gasket (looked perfect) then what? Examining the flow of liquid thru this engine shows that the 8 studs securing the rocket shaft mountings to the head are threaded into the water jackets of that casting. (BMC Engineering) Is it possible that water wicked its way up these threads into the oil bathed rocker shaft? Water under pressure, if not sealed properly could migrate upward and contaminate the oil. I’ll go with that theory.  I purchased some Locktite white sealant (small tube, big price) at the local auto parts house and coated all 8 studs which foul the water jacket openings. Reassembled the rocker; replaced and CopperKoted the head gasket; assembled the head carefully torquing the nuts to 70 ft. lbs. as required, in proper tightening order. Reset the valve clearance as things have changed by shaving the head. A compression test showed 150 lbs. in all 4 cylinders. I then started the engine. Ran perfect. 

Now for the acid test (ok, antifreeze test)! I added the cooling liquid back into the radiator as required and then restarted the car and ran it for a few minutes. No white liquids appeared. Two days later checked under the valve cover-again, no white liquid appeared. Its fixed?

So, I painted the two set pins gold (finished photo) and secured the valve cover…now what’s next?