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« on: May 07, 2006, 07:36:30 PM »
Hi,
My tuppenceworth.
The first thing I would check is the breather system on the machine as a blocked or restricted breather tube will cause oil to issue forth from the most carefully assembled engine. Cylinder bores and rings well past their best will also cause leaks but unless they are really worn lowering compression seriously and causing serious blowby, the motor should not leak badly if the breather is doing it's job.
The Triumph twin will mist a little round the pushrod tubes and at the ends of the rocker shafts, but not enough to embarass itself or its owner by dripping on the floor even if it is doing 300 miles per week provided it has been assembled with appropriate attention to mating surfaces, which should be flat, clean and dry.
These surfaces should be checked for flatness and any high spots dressed with great care. It's common for threaded holes to protrude slightly around the edges of the holes, preventing the mating surfaces from coming together properly. A steel rule is useful for checking for protruding edges and other little lumps, and a piece of plate glass of suitable size is useful for checking for flatness, and also, with the aid of grinding paste, for dressing joint surfaces which require something a bit more drastic.
I have used plastic metals like Belzona and JB Weld to fill and even repair damage of the sort caused by ham-fisted levering apart by big screwdrivers. Applied properly to a clean surface and allowed to cure properly before being flattened down has worked very well for me and often has got me more work than I wanted.
Gaskets, especially pattern items are often too tight around the screws when they are inserted, causing the gaskets to bunch up around the screws when they are tightened, again, stopping the joint faces from being pulled together properly. So it's a good idea to make sure the gasket is not tight around the screws.
When using cements and sealants, it is worth remembering that in these cases, less is nearly always preferable to more. You will rarely fill a gap successfully with silicone if there is even a little pressure on the joint. The bigger the gap, the harder to seal.
If the surface is well prepared, the thinnest coating possible applied, the gasket prepared beforehand if one is being used, and the parts assembled with the fasteners screwed in finger tight diagonally before being tightened, again diagonally, hand tight at first then finish tightened being careful NOT to overtighten, then oil leaks should not be a problem.
Careful assembly means no oil leaks, no sealant spoiling the appearance of your pride and joy by squeezing out, or restricting or even totally blocking oilways or stopping ball valves from seating because of gobs of it floating around inside. Remember, if you fit a casing and stuff squeezes out, it may just look bad to you. But if it squeezes out, it will also squeeze out of the joint on the inside and into oilways, which is much worse. I repeat - less is more.
The actions I describe cost very little, the cost is mainly time. If you want a piece of plate glass, train yourself to notice the next time you see a shop with a broken window, or better still, when a glaziers van is outside some business, talk to the guys and the chances are you'll get a suitable piece of plate glass for free (8mm will do at a pinch, 10mm or 12mm is ideal). The price of a packet of fags or a couple of pints should encourage the glaziers on the job to cut the scrap glass to a suitable size and even grind the edges off it.
Sealants? I've used windowseal, among other things for years with no problems.
Good luck with your TR6R, it is (or will be) a fine machine, arguably the best of the breed (I didn't like the later OIF machines, too tall, too bulky and too heavy).
I hope this is useful to you.
A.
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