When you say "safe" consider that Lycoming says the plane can go to TBO running at 2700RPM continuously.
Pascal
Can you please give me a reference for this information? So far I haven't been able to find that particular piece on info in the Lycoming publications.
Thanks
Keep in mind tach time, what TBO is based on, "runs" faster at the higher RPM...so you will get to that wonderful destination perhaps a bit faster AND for sure your major overhaul bill even faster!
An interesting consideration is the O-470-R versus the O-470-U. The -R model runs to 2700rpm with low compression Pistons making 235HP and has a TBO of 1500 hours. The -U model runs to 2400rpm with higher compression Pistons making 235HP and has a TBO of 2000 hours. This is all IIRC. Interesting how the TBO depends on rpm.
Also, while TBO is required for part 135 operations and not for part 91, I think the people talking about TBO are more referring to the time before an overhaul is needed due to condition more than the time before ov Rahul is needed because of regs.
Doesn't the R run at 2600 and U at 2400? That is what the Conti literature reports. Also, can be many differences with pistons, rings, inserts, cases, . . . the list goes on. So, we have talked about this before, but each engine as different weaknesses that might affect/yield a different TBO. RPM included.