Friday, June 17, 2011

Time's awastin'

I've got less than a year to go here. Gotta get to work.

Ok, here's what I've done recently (no pictures!)

The Suzuki forks are awaiting my friend's lathe to have threads cut in the top of the stanchions so they can screw into the Enfield fork crown. He's also going to cut a groove in the tops of the sliders to accept a standard Triumph style rubber fork gaiter.

I've started work on the Tomahawk engine. It has perfect looking top-end, cylinder bores, pistons, valves don't like like they need to be reworked.
The bottom end is a different story. It made an awful grinding sound when being turned over by hand, and felt very rough. I assumed the main bearings were breaking up.
What I found after partial disassembly (the drive side bearing is holding onto the crankshaft very tenaciously, and I'm looking for a suitable puller) is that the crankshaft wasn't quite installed correctly. It's supposed to be held in place on the drive side bearing using a spacer on the inside of the bearing race, and the engine sprocket and nut to pull the entire assembly tight. This establishes a certain amount of clearance on the timing end of the crankshaft.
Whoever put it together (I assumed, given the apparent low milage of the engine, that it was a "friday afternoon" factory assembly job) didn't pull the crankshaft tight against the drive side bearing, and the other end of the crankshaft was rubbing against a large sheet metal washer that's installed in the timing half of the crankcase to cover the bearing and end of the crankshaft.
Further inspection revealed that at some time, the engine had suffered a broken connecting rod. The case wasn't broken in the typical manner, so it didn't show up as a big hole in the front of the crankcase.
It did cause internal damage to the exhaust cam tunnel in the right side of the crankcase, and someone replaced the broken rod. This explained why the rod on one side was dark from age, and the rod on the side where I found the damage was still white aluminum.
The cam lobe on that side was rubbing the damaged metal which was pushed into the cam tunnel. Putting it together without fixing this damage was a mistake, because the damaged area was bad enough to allow oil to pour out of the cam tunnel, which is supposed to have a certain amount of oil in it at all times to lubricate the cam. I see no serious wear on the cam, either because there's still enough oil in there to keep that cam wet, or (more likely) because after reassembling the engine, they only started it up briefly, then shut it down and never ran it again. There wasn't much wear on the parts that were rubbing inside.
So once I've got the crankshaft out of the drive side case, I'll need to get some aluminum welding done to restore the cam tunnel. Didn't expect to have to be doing something like that!
I'll update this post with pictures after I've finished the disassembly.

I've also ordered some spokes for the wheels from Buchanan's.
They don't normally stock Royal Enfield spokes, so they had to make them up special.
They keep spoke specifications in a database, but the only Enfield spokes they listed were for the Interceptor. I ordered, and recieved a set of spokes for the rear wheel on the Interceptor. I also ordered a nifty spoke wrench which has one end that will work with most British wheels, and the other end will work with BMW slash-2 wheels. Its listed as the 210250 spoke wrench. That's because one end of it is 0.210" and the other end is 0.250".
I also sent them two spokes from the Tomahawk, which has 19 inch wheels with 6 inch brake hubs at both ends, so the spokes are the same. So if anyone needs replacement spokes for an Enfield with a 19 inch rear wheel, or a 19 inch front wheel with the 6 inch brake, they'll be able to make you a set.

Some progress. Not much but at least I'm moving on it.

No comments:

Post a Comment