SUPER FAST SUPE HAWK
On a related note, I tell you about a modification I did a few years back. I made my own adjustable cam sprocket, that way I could set the cam timing the same. I lost the centrifugal advance by doing so, which ment I had to push start it. The motor was super good runner, you hear how equal it was running. I had also hand selected thu my spares, the 2 most equal sets of cams. Their was lots of difference between cams, I might ad.
The advantage of a crank mounted system as Superchicken mentioned is that timing does not move. It stays where it's set. Cam timing is remarkably "flexible". These old bikes had an unsupported cam chain and it whips quite badly at speed. Admittedly a race motor runs at higher average RPMS and that results in lots of aluminum in the filter from the chain hitting things. A CB160 is worse. On a dyno, the timing can be seen to fluctuate at different speeds. At some speeds it will cycle back and forth - presumably some harmonics effect.
For a race bike an adjustable sprocket is a good idea. We remove about 3mm from the block and head to get the compression we're looking for and that would retard the cam by almost a whole tooth. Cam timing is rarely close to spec. even with new reground cams. We always degree in a new cam and then have to work out how we'll make it work. often one side is advanced versus the other but usually the closing and opening points are not where they should be, so we then have to look at th peak lift point to set lobe centers close to where we want them. Welding the little advancer is a good idea on a race motor, but crank mount the ignition and it's not necessary. When I first built that bike I had a heck of a time starting it, so I re-fitted the electric starter and that worked. Now it's all bump start for a race bike, so that isn't an issue. The cost of electronic ignitions will always be an issue for those of us that hate paying for the conversion. A Dyna set up is almost $200, Newtronics for a CB360 is about $250, Ignitech fully programmable is less but requires some fabrication. You could buy a complete GS750 system off ebay for a lot less but you are still working with old components and old technology. Early GS iused mechanical A/r. Later ones were electronic. For a sunday ride, it's a personal choice. Points worked back in the day and still work fine. Points require more maintenance and maybe that's part of the experience of owning an old bike. I personally liked to keep my street bikes in top condition, so all that fettling was part of knowing it was spot on. Today I just want to ride it and sit and look at it tinkling in the sun light after a ride.
Mr Spooge, I don't have a kick starter so NO, I'm not saying that.
LM, to the other issue you raised about bang for the buck. I'm not sure there is much if any improvement over well adjusted points. But my points never stayed that way for long, so to me it's worthwhile. That may not be true for everyone.
The probe Ignition does improve the power at all RPM's but the cost is where I figure it may or may not be worth it. (ridden bikes I installed the PROBE system on)
Sort of consider what is sort of the most used statement for members who need parts. "I need (that super rare, hard to find, most expensive) part and I would like it to be NOS/OEM and cheap". Get the pic?. .:-) ..............lm
I knew I had a picture somewhere of one of those Harmon and Collins roller cam kits and today I managed to dig one out. It's from an old Webco catalog of Hop Up parts.
Enjoy http://www.pinkpossum.com/cb72/images/H&C.jpg
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