I couldn't find an engine forum, so here goes....

I'm just finishing an AK Models 3D Freedom (finally) and have a Saito 150 on the front. I also have an APC 15 x 4W 3D / Fun Fly prop. Is this enough prop for this engine? Horizon's site lists a prop range from 14 x 10N up to a 18 x 6. I'm hoping the Wide designation might put this prop in that range, but I certainly don't want to over rev the engine, although I don't expent to spend much time at full throttle.

Advice appreciated.

Sotos
Newport News, VA

I'm afraid the APC 15-4 is too small for your engine. I run the APC 15-4 on the Saito .91 and a APC 17-6 on the 1.50. The 16-4 seems to work best with the Saito 1.20 on my Funtana (a 16-6 if I'm running 30% fuel) but at least for the Funtana and my Laser 200 the APC 17-6 is the way to go. A 15-4 is a good prop to bench run the engine during break-in but I wouldn't fly a plane with it, You need to keep the RPM'a under 10,000.

Thanks much for the input. I guess a new prop is in order. I see you are in Tappahannock, you guys have a club up there?

I run a 16-6 on my saito 120 with good results on the ohio yak. I would go with a 16-8 or 17-6 depending on ground clearance with a 150

I belong to the Hanover Propbusters near Richmond and the Northern Neck Flyers in Kilmarnock. Both are about 45minutes from the house in opposite directions. The good news is I have permission to fly at a Sod Farm 10 minutes from my house and the conditions are better then any club I have ever flown at. Not much comaraderie though I have come down to NNS city park to fly there a couple of times but every time I get there thereisn't anyone there and the gate is locked.

The 15x4 is definately too small for a 150 Saito. I have a YS .91 spinning a 15x6 with no problem. I would say the 17x6 is a better choice for the 150. I have a YS 1.10 which has been compared to the Saito 150 believe it or not. I have seen a video of the 1.10 spinning a 17x6 like it was nothing. I haven't flown my 1.10 yet, but everyone agrees the power is unbelievable and will put a Saito 120 to shame. So again, I would say a 17x6 or 8 should work fine. If the engine will spin a 17x8, then use a 18x6 for 3D. It will fly slower, but give more thrust.

Thanks guys. I guess it'll be the 18 x 6 then as this plane, if you don't know it, is basically a scaled up Somethin' Extra, with a big fat airfoil which definitely won't go very fast.

Steve, it's been a while since I've been to the NN field, but I hear it's pretty nice and the club has grown a lot in recent years. I'm sure it's well attended on weekends and probably Wednesday mornings. I prefer a drive to the country to fly, and head over to Isle of Wight. Also, Colonial Virginia Aeromodelers are having what they call a Something Different fly in next month which I may attend. Basicaly, you can fly anything that isn't a standard single wing, single engine, cruciform tail plane. Sounds like it'll be full of Bipes, Zagis and Wingos.

I have a Saito 150 on an EF Yak and am using an APC 18x6W. This prop works great for 3D.

Thanks for the tip Dean. That's what I 've decided on, hoping that the LHS has one as I think I'm ready to fly this beast which I started building well over a year ago. It sat untouched for over a year, I finally pull it down for completion, and it only took a little over two weeks two finsh. Sheesh.

Do you have any idea how many RPM's you're turning with the 18 x 6W??

Thanks.

Sotos - I am not positive, but I think I am in the mid to high 8's. This is a great engine. It has been very reliable, good idle, good transition - and it gets better with every tank. I can hover my Yak at less than 1/2, closer to 1/3 throttle. Good luck.