oceansfiftyseven

I had been running my new saito 40 with a Zinger 11x5 wood prop and thought I should be getting better rpm. When I switched to a 11x5 master airscrew I got more rpm than I thought possible with this little engine. Zinger 11x5 peak 9400, MAS 11x5 11,000+!!! I stopped adjustng the needle at 11K as I thought this to be too much. What props/rpm are you guys getting with this engine? Thanks

P-40 DRIVER

my Saito 40 will turn an 11/5 Zinger at 10000 on 20/20.

oceansfiftyseven

11x6 MAS 10,200,
9x7 MAS 3-Blade 11,300

oceansfiftyseven

10x8 MAS 10,300

rexracer

I broke in my .40a today. What a little jewel it is! Ran it at the factory "rich" setting (factory LS setting, 2 1/2 turns out HS) with glow heat for the first 10 mins, then upped it to 5000 and took of the power to the glowplug and ran the rest of the break in, per Hobbsy's procedure. Break in prop was a MA GF-3 11x6. After 40 min. I peaked the high speed, then leaned the LS for a good idle and transition. I left the LS alone for the rest of the tests, and richened the HS and peaked for all props tested. Here's what I got.

Temp 70f
humidity 60-70% (?)
wildcat 15% 18% oil-syth/castor blend

Top Flight Powerpoint 10x6
Peak RPM 10,500
idle 2800-3000
I was supprised at the load this one put on the engine. Didn't like to idle low with this small, light prop.

APC 11x5
peak RPM 10,300
idle 2200
static thrust 4lbs 5oz.

MA GF-3 11x6
peak RPM 10,350
idle 2200
static thrust 4lbs 7oz

MA GF-3 11x7
peak RPM 9350
idle 2200
static thrust 3lbs 11oz
Though this one loaded the engine quite alot, it may unload in the air and be a good prop for flying.

MA K series 12x4
peak RPM 10,200
idle 1800-2000
static thrust 4lbs 11oz
The engine really likes this one. Great thrust #s. I may start with this one on the beaver. had it idling at 1600 for about half a minute before it started stumbling. 1800 was a little rough, but good on the stand. 2000 would be good to fly, I think, though I'd probably set it at 2200 or so.

MA K series 12x6
peak RPM 8500
idle 1800-2000
static thrust 4lbs 4 oz
Too much load I would say. I'd be curious to see if this would unload to a descent RPM in the air. Spoolup was slow.
I ran the fuel out of the tank with this prop. It would turn at about 7500 at half to 2/3rds throttle pretty easily, and only seemed to start straining to get the last 1000RPMs. It ran about 4 or 5 minutes at 7500 RPM to burn the rest of the tank, and the engine was cool enough to put my finger on the side of the cylinder for 30 seconds before the heat would bother me.
I wish I had a 12x5...thought I did, but it turns out it was the 12x6. I may order a couple of graupners to try.

Here is a pick of my new baby, and the test rig I ran her on, and the props tested.




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Club Saito member #173

oceansfiftyseven

After a couple years of ocasional use with the MAS 9x7 3-blade prop. I finally decided it needed a little bit more load. So I cut down a 10x7 3-blade to 9.5x7 and balanced it. I backed of the needle 3 clicks and started the engine. Tach said: 10260. I had to lower the idle speed as it fared better with the heavier prop. Anyway, I did not peak the engine since it sounded so good where it was at. Take off was shorter, climb was better and the top speed seemed better. If you like 3-blade props, this one is worth trying!