Ever have a day when nothing went right and you just wondered why you bothered to try? Ever have one of those days when everything went right and you wondered how it could be so easy? Ever have one of those days when nothing went right,,, until that light bulb went off in your head and welded some appropriate synapses together and suddenly, life was good, there's a god and electrics are just a passing fad? Today was like that.

Thanks to Japanman, we have a solution to the impending obsolescence of millions of Cox engines. Not to mention the agonizing wait for Norvel plugs to re-appear. A secondary BIG honourable mention goes to Stewart, (SGC) for suggesting that stock Norvel plugs can be drilled and tapped for Turbo plugs.

As mentioned, JMan had provided a Cox plug modified for a turbo and also did up a blank I had sent him for the same type of plug. They provided no advantage so I shelved them till I had the opportunity to work with and improve the Brodak/CS engine. When I say provided no advantage, that is NOT a negative,, what I mean is that they were EQUAL to a stock Cox and Norvel plug. Really, a magnificent feat considering that the installation of standard plugs creates terrible gnashing of teeth and wailing about the loss of power. Not so with the turbos and that's the point. We can now make our own turbo devices, kudos to JMan for the Cox version and kudos to Stewart (SGC) for suggesting that the same could be done for Norvel plugs.

OK, here we go.

Initially I couldn't make a good result using Japanman's method of sharpening a common Phillips head bit. So, as related in the first thread on the subject, I found a countersink drill bit that had the correct angle and, along with the correct tap and the use of my Taig lathe, I was able to do up Cox plugs and also make turbo buttons from scratch. Great if you've got a lathe but what if you don't? So, I revisited how JMan did it. On a drill press but using the bit that worked so well for me.

That is pictured below.

First, you screw your plug into a Cox cylinder to act as a holding fixture and firmly, and squarely install that on to your drill press vise.

Then you use a razor saw to cut off the crimp to release the center post. Be sure to dig out the filament. Take out the plug and use a sanding block against the top face to clean it up. Reinstall and make sure the plug is now tightly screwed in.

Then you drill out the plug using the tapered drill. Note the collar to act as a depth stop.

Then you use the 9/32" drill bit for the threaded portion. Another collar as a stop.

Next, use the drill press as a guide to make sure the tap runs dead square into the bore. No, freehand won't do, I don't care how good an eye you've got. It has to be PERFECT. Chuck up the tap very lightly, we don't want it to stick, just use it as a guide. Slide your plug underneath and using some small pliers, draw down the tap and start turning. Note the beautiful chip, just starting. Start it dry, then add some tapping fluid and just work it back and forth by hand till the tap bottoms out.

Once done, clean up the underside with a mounted stone to take off the burr that will develop.

Clean it up thoroughly with soap and water and don't forget to work the threads firmly with a Q-tip. You absolutely must do this, them chips embed themselves into the threads pretty solid.

Finally, the turbo plug has a diameter larger than the bore of the head clamp so this must be drilled out to 3/8".

OK, you're done, you're so smart you oughta president.

But uh, oh, testing it on your engine shows a serious leak. NO MATTER HOW TIGHT YOU MAKE IT. What, miscalculated on the depth stops? Can't be I used a good one done on the lathe as a guide. OK, maybe got it wrong, maybe the threads aren't going deep enough. Drill and tap a bit deeper. Nope, still leaking. What the,,, OK, dress up the seat with the counter-bore,, just a bit,, not too much. Ah sh**t, (shoot) bored clear through. DANG.

OK, start all over again, this time paying REAL CLOSE attention to how deep we go with both bits. NOPE, that wasn't it. OK, try a third, this time using a feeler gauge to adjust the depth, bit by bit. Nope, the *&%$#@ thing still leaks. That's the third plug and now I'm clean outa bad plugs. Oh god, no, I'm going to have to trash a GOOD plug??? At 12 bucks a pop?

This nonsense took all afternoon.

Well, if I have to sacrifice a good plug I'm going to have to sit back and rethink the entire procedure.

To be continued,,,,