i'm in the process of trying to rebuild two motors, T120R & T120RV. i was at a shop looking for camshafts and found a set that looked close, but i'm not sure. the part number on one of them was HC 6739. does anybody know something about it?
Any number cast into a Triumph motorcycle part is just that, a casting number. The casting numbers do not directly relate to any particular Triumph part number you will find in any Triumph parts book. The casting number refered to the part before any machine work had ever been performed. Think of the casting number as the part number for the unground camshaft blank. Two or more completely different factory cam grinds can have identical casting numbers.
thanks for the reply. the number on the cam looks like it was stamped and not cast. could that be a sign that these are aftermarket cams? you'll have to excuse me, this is my first build, so i'm still learning a lot about this stuff. the guy at the shop said i should bring in my old cams and we'll spec them to see if the ones he has are the same. my lobes are toasted otherwise i'd use them. it looks like a really bad re-grind.
so, anyway, i grabbed 'em. they were $130. the going rate for triumph cams is almost 3 times that. dimensionally they look similar to a johnson t75 cam. more lift than stock, and definitely better than the re-ground stock cams that i had. it's nice to get a deal sometimes! if anyone knows anything about the origin (just in case that # on the cam means something) i'd like to know.
If the number has been added it very well may be an aftermarket regrinder's part number. Harmon and Collins comes to mind. They were a very well known and respected performance camshaft company back in the day. I believe they are long gone now, but a quick Google could shed some light.