ggriffith

So, to answer the questions: Piston ring gap was bang on what it said in the book (I think 0.3mm, but the book is in the garage). This was on all 4 cylinders, measured at top, and middle (but not the bottom as I couldn't get the feeler gauge down that far. I did indeed use one of those three pronged whilygig honing things on the end of a drill. And I kept the crankshaft clean by first cleaning it with degreaser, then wrapping it with cloths. Then honing the cylinders, then taking the cloths of, and then cleaning it again.  I also made sure that the head was smooth, rubbing it down with 400 grit wet and dry, reground the valves, new gaskets where needed, (oh and a real struggle with the joint between exhaust manifold and exhaust downpipe, had to resort to exhaust compound to get a good seal). I also figured I'd change the oil over after a hundred miles or so, just in case there was any muck in there that would be best out. That and I couldn't readily find an oil filter that fitted. So, fingers crossed. I'll take it out for a bit of a gentle drive at the weekend and see how it goes. I've run it in the garage for 20mins and got it up to temperature, and all seems find at the moment.   

For what it's worth...I honed the cylinders (block still in situ) and then refitted the pistons with new rings. Refitted the head, (having reseated the valves) and then all the cooling system. Started it up, and it's running beautifully. I'll take it out for a run shortly and after a hundred miles or so I'll change the oil just to be sure it's free of any contaminants. It seems to be burning significantly less oil, but I can't really tell for a bit.  So thanks for your advice all. And hope to see some of you at some West Country Triumph events. George  

OK, would you suggest then that I get a honing tool (any suggestions?) and then give it a bit of a hone. I'll cover the crankshaft with some cloth, and give it a good clean afterwards.  I'm reluctant to take the crankcase out of the car. So I'll try and do that with it in situ. One more question, what tools would I need to measure the cylinder, for taper and ovality? Can I come by them relatively cheaply? Again, reluctant to take cylinder block out and the car's not going to go very far at the moment! I really hadn't planned on a total engine rebuild.  So any thoughts much appreciated.    

I have a 1976 1500 which I recently purchased, anticipating a bit of work. However, in trying to reduce the smoke it produced I've found myself wanting to replace the piston rings. I've currently got the head off, and the pistons out (cylinder block still in car). Several questions...what would I see if the piston rings were allowing oil to leak into the combustion chamber? How smooth should the cylinders be? to my untrained fingers, they feel as smooth as the proverbial baby's bottom. No obvious lines at top or bottom. I've measured the gap on the existing piston rings to be about 1mm. I believe the book says about 0.3mm is what it should be. Do you think that the increase in gap is due to wear and could be the cause of my oil burning? Do you think I should hone the cylinders? I'm reluctant as I don't want to take the car any further to pieces, and am worried about getting residue from honing on the crank shaft (and that generally being a 'bad thing'). For info, I have reground the valves, and they now make a much better seal. They definitely needed that. And two cylinder heads were black and oily (2 and 3) and the other two seemed to be what passes for normal. I'm in Bristol if anyone is nearby.