OS 108 RPM
03-14-2006, 01:48 PM
#1
OS 108 RPM
I was just wondering about the revs I can turn with my 108. The instructions say up to 16,000rpm. Is there any problem puting a tuned pipe on this engine and runing it up to around 14K for a speed type airplane? The reason I ask is that I already have the engine and would like to use it.
03-15-2006, 10:20 AM
#2
My Feedback: (11)
RE: OS 108 RPM
For speed, you'd use small-diameter props with high pitch. This would get the engine turning up. Don't expect much of an idle, though, when you go for higher RPM, the idle goes away. To get the best speed, you'll also need a very clean airframe.
We normally turn the 1.08 in the mid-9,000's with a 16 x 8 APC prop. This give the best all-around performance and handling.
We normally turn the 1.08 in the mid-9,000's with a 16 x 8 APC prop. This give the best all-around performance and handling.
03-15-2006, 12:42 PM
#3
RE: OS 108 RPM
I understand about using the right prop. I was just wondering why as you say "We normally turn the 1.08 in the mid-9,000's with a 16 x 8 APC prop" when the engine is rated for 16k rpm. I understand this about other engines that are rated for a max of say 11k rpm but anyway, thanks for the response.
03-20-2006, 02:15 PM
#4
My Feedback: (11)
RE: OS 108 RPM
The RPM range stated in the manufacturer's specifications show the maximum and minumum RPM that the engine was run at. The maximum is like the "red line" speed. My car red lines at 6,500 RPM, but it normally runs at about 2,100-3,000 RPM in normal driving. If I tried to run it at the high end of the range, the engine wouldn't last very long at all.
