Hi all, I know that if I painstakingly search the archives I could probably find out what I'm looking for, but I'll ask anyway because of my lethargy.... My friend Mike wishes to get some advice about cams for his 850. He wants to stick with a standard type cam, no performance hot cams please. He has heard that Megacycle cams are the way to go, and is wondering what the best deal is out there for a good quality replacement. Does anyone have any recommendations? He doesn't want to spend an arm and a leg, but wants a quality cam that will be long lived. This bike will be a daily rider. In a related matter, are 750 camshafts and 850 ones interchangeable? The reason for this question is that he has a reasonably good condition 750 cam on the bench and it may be useful if the price for a new cam is too high. Please let us know if you have any advice, it will be most welcome, I am not knowledgeable about cams and their properties. Thanks, cheers, Gary

65 Atlas 750 69 Mercury w/ 65 N15CS engine

The 061084 cam is the same for 750/850 The early 70-71 cams are usually pretty good for hardness (hi RC40 to 50's). These are cam end breather cams. The no scroll cams are 72/73 and I have found them to be softer, they tend to be mid RC30's. These can be made into scrolled type with a wide ginder wheel on a dremel, and a little care. Megacycle cost about the same as a genuine norton. MC are good quality, but I think people use the 96000 for bragging rights more than performance. The NR (IIRC) would be my choice in an 850 (or stock cam). If the low compression is to be raised, then I might bump up the cam a bit more.

RE Compression, Map Cycle is supposed to have 9.5-1 850 pistons, with valve pockets, available at the end of the month. I'm planning on using those and Megacycle's 506-NSS cam in my MkIII motor. I can live with the valve clearance that it calls for. Some of the others with larger clearance might be too noisy for me on an everyday rider. TP