Re: install cam technical question
Posted: Sat Jul 10, 2021 3:25 pm
Guenther Wuest is certainly one of the gurus, so you're in good hands!
I know very little about performance enhancements for engines, but you mentioned something that made me wonder. You say you're putting in a mild cam. One thing that I've read about is the R60/5 and R60/6 bikes at 9.5:1 compression also had a mild cam and they were very prone to pinging. (Mild cams to me means they have a more shallow rise/fall of the lobes, keeping the valves closed longer resulting in more compression.) Ways of dealing with that was base gaskets or use of electronic ignition which controlled the advance curve to reduce pinging. I suppose dual plugging was an answer but was an expensive one at the time. Dual plugging requires further manipulation of the advance. You can't let the engine get advanced too early otherwise it will ping. One way to prevent this was to build in a mechanical stop on the advance unit...this allowed for keeping the original timing at idle. Another way was to forgo the idle timing and having the points open at very nearly TDC, which would allow for the regular advance curve but it terminated early.
But if Guenther has a way around these things, that will help out!
I know very little about performance enhancements for engines, but you mentioned something that made me wonder. You say you're putting in a mild cam. One thing that I've read about is the R60/5 and R60/6 bikes at 9.5:1 compression also had a mild cam and they were very prone to pinging. (Mild cams to me means they have a more shallow rise/fall of the lobes, keeping the valves closed longer resulting in more compression.) Ways of dealing with that was base gaskets or use of electronic ignition which controlled the advance curve to reduce pinging. I suppose dual plugging was an answer but was an expensive one at the time. Dual plugging requires further manipulation of the advance. You can't let the engine get advanced too early otherwise it will ping. One way to prevent this was to build in a mechanical stop on the advance unit...this allowed for keeping the original timing at idle. Another way was to forgo the idle timing and having the points open at very nearly TDC, which would allow for the regular advance curve but it terminated early.
But if Guenther has a way around these things, that will help out!