Self-Inflicted Pain—Overheating Puzzle Solved

(See below for a better solution!)

Newer members won’t even know that I have a smart-looking, bright red, two-seat special as it has been off the road for so long with major over-heating problems.  On tick-over, it would boil within 5 minutes and on the road, the temperature gauge gradually crept up and up and up ……

All the usual suspects were eliminated—blocked head, blocked hoses, blocked radiator, retarded ignition—without success and so the spending had to start: new radiator core, electric fan, electric water pump. Again, without any real improvement.

Then I read an article (in the A7CA mag?) where the lower water manifold, the one behind the oil filler tube, was so blocked the water failed to circulate. Although having checked this over and over again, I thought one more desperate investigation was called-for.

And then the penny dropped!

Look at photo 1—there is hardly any space around the bolts for the water to circulate. A couple of years ago, I had reamed-out the threads in the block rather over enthusiastically to take larger bolts, to get a good grip, to 7/16th. I even had to drill out the aluminium manifold to take the massive bolts. It sorted out the dreaded leaking manifold alright! But unwittingly I had introduced a blockage of my own making and, for some reason, I never made the connection between the work I had done and the over-heating.

There are several solutions from this point on in the story and I have probably chosen the hardest route—to make my own stepped studs. The problem was to get a step from 7/16th down to 3/16th. My solution was to cut off the threaded end from a 7/16th bolt and drill a hole down its centre to take a peg. Then to turn down one end of a suitable, standard 3/16th stud for the peg and weld the two together!

Still, it worked!! And now the Little Red Car as it’s fondly known or, to give it its proper title, the BC Special after our chairman Bernard Cowley who once marketed them, runs happily about like every other good little Austin 7 should.

Moral:

If anything changes ask yourself what you’ve just done

Think before trying to be a clever ass. (See below!)

David Whetton

 

WATER MANIFOLD BIG BOLTS - UPDATE

Following the above article, I received several ‘helpful’ hints basically all saying the same thing—there was a much simpler way to do it, David!  And there was, of course. To recap—the problem was that, in the past, I had tapped-out the lower water manifold’s bolts to an unacceptably large size, resulting in the actual water passages themselves being blocked by the big fat bolts. My over-complicated solution was to make for myself a couple of stepped studs by cutting off the screw-in ends of the bolts, welding them to slimmer studs and replacing the manifold with a new one with original sized holes.

What I hadn’t realised, apart from the difficulty of what I was trying to do, was that if you replace the bolts with studs, you have, for evermore, to pull the manifold off the studs. But, as in my case, if the oil filler tube is reluctant to unscrew from the crankcase, there was only one solution—to saw the oil filler tube in half!! Coals heaped onto coals!

The simple, and straightforward, solution would have been to turn down the body of the fat bolts to let the water through leaving the screw-in end intact, the top of the bolt fitting the enlarged holes in the manifold and, of course, leaving the oil filler tube in place—simple!

David Whetton