May I ask why you would want to do it? Cams in airheads if the oil is changed regularly with the proper oil can last hundreds of thousands of miles before they need replaced. Or at least, that is my experience.
There were a few people who installed the BMW high performance cams back in the day and it does increase performance on a race track but decreases ride ability for normal street riding.
The R90S cam is according to the BMW microfiche the same cam as the /6 and /7 bikes, a good cam for the design that works very well for street riding.
Okay, so I am giving a lot more information than a simple yes or no to your question, sorry, I am just nosey, LOL. St.
I am going to install a siedelbrock 1000 cc kit in the bike and want a little more cam, probably the BMW 320. Since I have no plans to undo many of the previous owners mods and this is only a R90s in appearance I am doing a few more mods to satisfy me personally.
You are on the right track getting feedback from BMW airhead shops regarding this upgrade. I would advise to take some of their advice with a grain of salt, remember, they may be trying to sell you more than you need.
I have seen a lot of "modifications" done to other people's bikes at great cost to them resulting in sometimes vast improvement of power and handling, sadly however, also negligible improvements. For example, I raised the compression ratio on my bike from the US 8.5 to 1 up to the European 9.5 to 1 and to be honest, don't notice any difference in performance or MPG. Now, I did the upgrade at a time when the cylinders were shot and I needed to rebuild anyway, so the cost was there, and going up in compression did not add to the build anymore than rebuilding stock.
Getting back to my possible comment about my upgrading to 1000cc kit, I am on the fence because I have not had enough positive feedback regarding the cost versus performance taking apart a good running bike to perhaps improve power. Now, at the time the engine needs another full rebuild, I may then spend the money and go whole hog.
I am chatty this morning, it is raining and I haven't got the ambition to work on my restoration project hence, I am rambling on the forum. St.
'78 R100/7 '69 R69S '52 R25/2
Now my R75/7, used to ping all the time but only when the points got out of adjustment which is why the 78 RS has the points removed and a electronic system installed. I only have to adjust timing if I take the unit apart. Timing stays where it should and no ping.
In reality, I can't really notice the difference in performance between the stock 8.5 to 1 compression in my RT versus the rebuild 9.5 to 1. Funny as well, there was no big performance gain from just rebuilding worn out cylinders. Of course the oil consumption went down, and the clanging and banging the pistons were making in the worn out jugs went away.
I have never put one of the bikes on a dyno to see what if any gains in HP or torque are. I sure am pressed to feel it in the seat of my pants while riding. St.
And your point of "noticing" a difference with the upgrade. I think that is something that people don't really consider. It is, after all, a 1970s design. I don't think there are a lot of spaces in the design to really help the performance out...it's like a zero-sum game. Improve the top end, but hurt the mid-range. So, it seems like throwing money at the bike doesn't really give the return...at least from an engine standpoint. I think the suspension area can be improved with better forks, stiffening the frame, better shocks, etc. There I think a person who pushes the bike will notice the difference. But engine horsepower...not so much. You have to be a Udo Gietl for that!
'78 R100/7 '69 R69S '52 R25/2
I fully agree suspension modifications are worth it even if like me, I don't drag my foot pegs in corners riding at the edge, personally, the street is not the place to be riding so aggressively. So yes, I added a fork brace and beefed up triple clamp, but, I didn't spend mega bucks on super duper high performance shocks and springs, Ikons work just fine for me and my riding style. Same goes for tire choice, I go for long wear over performance as long as the tires perform as needed.
As it is raining here, I am taking up forum space. The great thing is for airhead owners, a great deal of new and improved items out there at reasonable cost and everyone can do what they like with their bikes. Enjoy the riding. St