About a year ago, in a post about 7535 performance, throughout most of the post I typoed '7545' instead of '7535'. Saying
"No, I'm not saying that I would prefer to run the 7535. There are five classes of overspeed (Categories Ia, Ib, IIa, IIb, and III). Running an O-200, you can easily reach a IIb overspeed with the 7545 (I was careful not to exceed IIa, which has the same inspection requirements as Ib). You can probably reach IIb with a C90 as well. A IIb overspeed would require that you replace the rod bolts and nuts, among a number of other unpleasant and potentially more expensive consequences. I've run a 7441, liked it, think a 7440 would do better than the 41, and that a 39 might be better still (I'm not in a hurry to get anywhere in a cub). Any flatter, and you run a severe risk of hurting the engine. I run a 7142 on a daily basis and think that on an O-200 (and probably a 90) it is a great compromise prop that won't lead a prudent pilot to hurt the engine. Being careless with the 7545 could lead to the need for an overhaul or worse within a very short period of time. That said, the 7545 performance is quite impressive, including a 55 mph climb at full rated rpm (2750 rpm) on a 95 degree day -- the 7545 just comes with a potentially exorbitant penalty".
Needless to say, I meant to say, "7535" instead of "7545". Nobody commented, so I figure all of you knew what I meant, but I thought I'd take this opportunity to correct it anyway.
BTW, my 7441 has been repitched to 7440, and I'm looking forward to comparing it against my 7142, but FedEx has been bouncing the package back and forth between Portland and Everett for two weeks now (was supposed to have come to a small town near Memphis). FedEx says it is being mis-scanned (15 scans so far between Portland and Everett), but they also say they can't do anything to stop the bouncing or redirect it toward Memphis.
Oops & Arrgh,
JimC