IO 540 Performance

pheastman3 · Post by **pheastman3** » Fri Jan 10, 2020 2:10 pm

would appreciate your input on power settings for IO 540. This is for a MT7 235. I am trying to determine what I should expect based on MP/RPM, Fuel Burn and Airspeed.

Gary Raser · Post by **Gary Raser** » Fri Jan 10, 2020 2:49 pm

I have a M7-235 I run 22 squared burning 13.7 to 14 gal per hr at 3,000 to 5,000 ft â€œprobably richer then I need to beâ€ and speed is right around 125 knots with 8.50 X 6 tires

pheastman3 · Post by **pheastman3** » Fri Jan 10, 2020 3:24 pm

thank you. that is very helpful. will be test flying next week.

jdsmaule · Post by **jdsmaule** » Thu Feb 20, 2020 9:26 am

Here are some numbers on my M-6-235 w/ mod 26 on 8.50x6:

11,500ft 145mph TAS @10.7gph 19.3" 2200rpm 63% LOP
7,500ft 150mph TAS @ 12.6gph 22.0" 2200rpm 74%
4,500ft 142mph TAS @ 12.6gph 22.3" 2200rpm 74%
2,500ft 148mph TAS @15.3gph 24.0" 2200rpm 78% ROP

Hope these numbers help. I don't recall if the 74% settings were LOP or ROP. I routinely use the Lycoming manual for leaning based on their percent power vs min fuel flow chart.

pheastman3 · Post by **pheastman3** » Thu Feb 20, 2020 5:20 pm

That helps. Thanks