I have owned 2 of the areo 26's and 1 of the 20's the car version has the notable larger carb up
close to the induction point allowing more rpm right off. I have not heard the cam has any change
for the car engine. I have heard no load rpm up to 19k.
The plane designs I have used have been varied the two faster setups really allow the engine to unload.
I am not sure of the rpm back then but would say over 15k in the dives with a APC 9x6
I tested two small 4cyl. engines here are the results. OS 26 surpass and Saito 30:
Both with the same prop to keep things even in that regard MA 9x7 and same spinner.
https://www.youtube.com/watch?v=X_2dtx22Zy8
Published on Nov 8, 2015
Bench tested: OS FS .26 Surpass 4 cyl. engine
Master Airscrew 9x7 Scimitar S-2 Prop
10,981 to 11,143 set bit rich as this is a jewel of an engine needs to last.
74 mph static and estimate 12,700 unloaded for 84 mph level passes.
After this run I fine tuned the idle to a steady 3.8 to 4.1k rpm.
25% nitro 14% castor 8% synthetic.
Tru Turn 1.75in Aluminum sport spinner.
https://www.youtube.com/watch?v=nRq_Ngbz2iU
Published on Nov 21, 2015
Saito FA-30S 4cyl Bench Test Master Airscrew 9x7 Scimitar S-2 Prop
Best Static: 12,273 rpm / 2.85 lbs (46oz) / .61hp / 456w / 81.3 mph unloaded est 93 mph level pass.
New engine tested for rpm after 7.5oz of fuel.
25% nitro 14% castor 8% synthetic.
Tru Turn 1.75in Aluminum sport spinner.
I left the OS .26 alone and did more testing with the Saito .30 as this one was new to me.
The goal was top end speed here is the static results:
https://www.youtube.com/watch?v=VyTge_TwGGE
Published on Nov 22, 2015
Saito FA-30S APC 8x8 / larger FA-40 muffler
Static: 12.596
2.2+ lbs of thrust / 47hp / 352w. 96.4mph / unloaded est 110 mph. +
VP Racing - Power Master YS / Saito fuel 20% Red Line Oil / 20% Nitro
After full break in:
12.92k and idle set steady to 3.39k rpm.
2.45 lbs (39oz) thrust / .51 hp / 379w / 98 mph / est unloaded 112 mph + level passes.
Note the spinner blankets some of the thick airfoil around the hub and helps reduce load
regardless of the additional mass from the aluminum spinner. Proven by the following
vid with a bullet spinner and fully exposed 1in pitch less APC 8x7 prop.
https://www.youtube.com/watch?v=AHsrQ6UMwTU
Published on Nov 27, 2015
Saito FA-30 APC 8x7 Tru Turn Bullet Sinner and FA-40 Muffler
12,600 to 12,760 rpm / 3,875 idle
2.3lbs thrust 85mph / .43hp / 321w
Low weight prop /spinner option for low engine load.