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Old 12-30-2012, 10:36 AM   #28
Joined: May 2012
Oddometer: 49
New 336° cam from BMW

Originally Posted by AntonLargiader View Post
To me, a 1070 kit with Mikunis would look [sort of] the same as an R50. Close enough!

Ha ! I wish. I run in AHRMA Production Lightweight , and I must keep the same stroke and bore (plus a small overbore is allowed). I am running the R50/R60 /5/6 Bings, those are the only allowed carbs. Then again, you know all this because I believe you have built a R75/5 AHRMA racer in the past...

There is not a lot of information on making the R50/5 go fast and keeping it a 500cc. Most just suggest putting a 600 or 750 top end on it. That is fine for the street, but I need to keep it 500cc and production looking from the outside. A lot of questions:

Will the 600 heads work ? Or will the valves hit the cylinder walls ? What is the best valve size for the 500 ?
What is the best cam profile for the 500cc displacement ?
What is the best way to raise the compression ? Dual plugging is not an option so I am worried a piston with too much dome will not provide an efficient burn on a single plug.

So many options, so little time…


DanMay is offline   Reply With Quote