Skybolt
Active Member
- Joined
- Apr 30, 2020
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Hello
I am trying to determine the actual redline rpm of the Continental 85-12 in the J3 I now own. I searched for redline on this forum and found information that suggests it may be above 2500rpm, but the conversations were muddled with 0-200 crankshafts.
Looking at the TCDS for C-85-12 I see:
Max. continuous hp., r.p.m., full throttle at sea level pressure altitude 85-2575
Takeoff hp., 5 min., r.p.m. full throttle at sea level pressure altitude 85-2575 (87-2650 for -J, -FHJ and -FJ models only)
I am a little confused by this wording. Max continuous rpm sounds like it can be run forever at that rpm, yet directly below it states 5 minutes max. Which is it? Is 2575 what should be on the tach for a redline? The reason I ask is that someone put a redline of 2450 on the tach on my new to me cub, and I have been observing it until I could determine more. Looks like it is incorrect.
If 2575 is correct for redline, what is a good number for the top of the green arc, assuming such a thing exists for this engine?
I am trying to determine the actual redline rpm of the Continental 85-12 in the J3 I now own. I searched for redline on this forum and found information that suggests it may be above 2500rpm, but the conversations were muddled with 0-200 crankshafts.
Looking at the TCDS for C-85-12 I see:
Max. continuous hp., r.p.m., full throttle at sea level pressure altitude 85-2575
Takeoff hp., 5 min., r.p.m. full throttle at sea level pressure altitude 85-2575 (87-2650 for -J, -FHJ and -FJ models only)
I am a little confused by this wording. Max continuous rpm sounds like it can be run forever at that rpm, yet directly below it states 5 minutes max. Which is it? Is 2575 what should be on the tach for a redline? The reason I ask is that someone put a redline of 2450 on the tach on my new to me cub, and I have been observing it until I could determine more. Looks like it is incorrect.
If 2575 is correct for redline, what is a good number for the top of the green arc, assuming such a thing exists for this engine?
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