Project Norton
Slowly the engine gets put together and the tank gets some love
Two STEPS FORWARD, ONE STEP BACK. I'M NOT learning to dance, but this is how my attempts at building a Norton ES2are going. I'm going to repeat this until I am riding it around; do not buy a box of parts masquerading as a motorbike ...
Last month I shimmed up the bottom end. And this is the reality oflife on a magazine; quite often a project has to wait several weeks until worked on again - life, work, family and, in my case, an old car engine and a BMWboxer got in the way. But while in the workshop measuring tolerances in my Opel Kadett engine (well someone has to like them) I had a feeling - that sixth sense - that something was amiss with what I'd done on the Norton. So I measured the crank end float again and there was nothing. So I popped the cases apart. Sounds easy, but it involved more heat to remove the crank from the outer ball bearing.
I guessed I had been measuring the float with heat still giving a tolerance, but once everything was a similar temperature, it all closed up. I thought initially I'd take more off the crank as the fit to the ball bearing (the crank has two expensive roller bearings, one each side, with an additional, cheaper ball bearing on the output side to give a helping hand) was still too
"I thought initiaIIy I'd take more off the crank as the fit to the baIIbearing was stiII too tight. But it just didn't add up"
tight. But it just didn't add up. I'd kept the original bearing and tried that, which felt fine. So do I keep rubbing down the crank, which feels wrong, to fit the new, unbranded bearing from a Norton specialist, or use the old bearing which was an SKF(a well-known, good make) which felt fine and fitted perfectly? I don't know what it's done in life, but I refitted the old bearing. It fits perfectly, is quiet when spun up and has no sideways movement, the numbers are right and this isn't a race engine.
Refitting it had to wait, as I had decided to fix the primary chaincase fitting. This is a part of the crankcase which has a thread coming out to help hold the chaincase in place, but some butcher beforehand had broken it, then fixed it with chemical metal. To be fair, it had stood the test of time, but the constant heating up of the case and the repair cried 'enough'. So superwelder, Steve, rebuilt the area with TIG,having first drilled a hole on the inside to help prevent the build-up of gases as he filled the old hole.
I wanted to use an M8 thread as that's what I had closest to the old fitting, so I drilled a 3mm pilot on the pillar drill (to help keep it vertical) and then a 5.5mm hole, which I then used an M8x 1.25 tap to create a good thread. After cleaning up the thread on the bar I'd cut, I popped it in for now but may make another with an untapped area that should help prevent any oil coming through the thread. I'll use Loctite 270 which is a fairly permanent thread lock.
Getting everything back together felt much better and with everything seated correctly, square and in place, I had 1.45mm (0.057in) endfloat. Slightly too much, but the bearings came with spacers, and I'll try to get just under the recommended 0.S0in (1.27mm) as the joint sealer will add a little.
For sealer I'm usingWellseal. It can be a little runny, so Neville recommended I squeeze out what I need and leave it for an hour or so, in which time it starts to harden slightly and is easier to use. But that has to wait for the tappet guides to be repaired, which need the other crankcase heated up to fit, once the tappets have been repaired, as they can only be fitted with the guides.
So while waiting for more parts and for jobs that have come to a halt due to the world closing, the never-ending search of jobs to do continues with the piston. In good order, I had the barrel honed out to match it, so spent a little time dressing the piston
''As a note, the Norton manuals do not recommend cleaningthe old carbonout of the piston ring gaps if you're using the originalrings"
lands and cleaning the piston ring gap of carbon. For this I use my trusty dental picks - which have so many uses I'm amazed you can't buy them from tool shops. I also popped the rings down the barrel to check the ring clearance, which should be .008- .010in for compression rings (the top two rings) and the oil ring (bottom, thicker ring). As a note, the Norton manuals do not recommend cleaning the old carbon out of the piston ring gaps if you're using the original rings.
The gudgeon pin fits beautifully to the little end of the con rod, but will need pressing into the piston, with the 'one in freezer, other heated up' method I guess, too. We are starting to get there.
SORT YOUR HEAD OUT
I really thought this month would progress more, now the lockdown was less restrictive and I had ordered a few parts. Matt at BDKheated up the cylinder head to be able to remove the valve guides, which were worn. They use a very serious piece of kit, a single hot plate - which is also to be seen to cook lunch sometimes! Still, it works perfectly and Matt used the method of using spit to see if it sizzles at the edge to determine the best heat. Charles then held it (with welding gloves) while Matt used a special drift to pop out the guides. And a bit of Coke can ...
Judging by the marks in the combustion chamber, a valve had lost its head at some point, probably leading to new guides being fitted. However, if you don't get the heat hot enough, removing old guides can also have you removing some alloy from the head. A typical 'old boy' fix is to sleeve the new
(now undersize) guides with a drinks can or similar. Therefore, my new guides flapped around in the holes, and were pronounced useless. I've ordered some oversize, for which we'll have to ream out the hole for.
While there, I also sorted the mounting face on the mill. This was from when superwelder, Steve, had repaired the broken fins. Because the barrel has a lip which corresponds to a recess in the head, I had to be careful, taking small skims until I was happy. At least that went well!
In magazine world, project bikes were always about how to do guides and amazing bikes at the end. I'm struggling, to be honest. Machining and specialist jobs mean relying on others, which means money, which is hard to come by, or favours, which leaves me feeling guilty. Working on older engines means most jobs for me are new, so it's a learning curve, too. And just trying to keep the momentum seems difficult at times. It may not be a typical magazine build, but it is real; so if you feel like a project of yours is hard sometimes, I know how you feel.
But there is a glimmer oflight in the distance. I sold yet another bike recently, so there is a few quid available; but then I haven't touched the gearbox yet and if it was from the same bike as the engine, heaven only knows what condition that'll be in! We'll see very soon.
Next Month: The plan is sort the tank and get the engine together and in the frame. We can but hope!
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