G-23 Prop revisited

Ok, guys, I appreciate your suggestions on prop selection. Really. :) A lot of you responded with your favorite recommendations.

What I learned today was on a 13 3/4-pound, 72" Dr.1 even largest recommended size (18-8) doesn't do crap. I'd have hated to try to fly it with some of the smaller suggested sizes. The G-23 had plenty of power, but the big Fokker didn't have enough pull to get out of its own way. The engine was screaming but the plane wasn't going anywhere. Can you say "cavitation"? I'm headed to the hobby shop for a 20-5 or maybe even a 22-4. My first Dr.1 flew nicely at half throttle with a G-38 swinging a 22-6. I believe a draggy plane like this one needs the larger swept diameter/lower pitch for more pull and better efficiency.

I used the recommended 2-cycle oil at 32:1. The engine ran fine on the test stand, but cut out in the air on final approach. It's had 80 oz. through it so far. Any ideas? Dr.1 Driver "There's a Hun in the sun!"

Reply to
Dr1Driver
Loading thread data ...

Weedie type engines take MUCCCCH longer to break in. Try 640 oz. thru it before it starts running well. I'm gettng ready to fly a ~14lb Super Cub with a Ryobi 31 - that spent several gallons worth of time actually cutting weeds at our flying field

David

Reply to
David AMA40795 / KC5UH

Damn! My G-38 didn't take almost 5 gallons to break in! I hope this one doesn't take that much. Can you explain the difference between is running good on the bench and then shutting off in the air? Dr.1 Driver "There's a Hun in the sun!"

Reply to
Dr1Driver

The prop "unloads" in the air . . . . ?

Richen the mix and see what happens. Cheers, Fred McClellan The House Of Balsa Dust

formatting link

Reply to
Fred McClellan

Have you done the carb mod... Solder a tube into the hole in the diaphram cover, connect fuel tubing and run it into the calm air inside the fuselage.

I have pics on my website...

formatting link
... about half way down the page.

-- Philip Rawson

formatting link

Reply to
Philip Rawson

Never heard of it. I'll check your website. Thanks! Dr.1 Driver "There's a Hun in the sun!"

Reply to
Dr1Driver

Could be, Fred, could be... Dr.1 Driver "There's a Hun in the sun!"

Reply to
Dr1Driver

An 18-8 is too much prop. An 18-6 would be better. The G23 is notorious for changing mixture with different airflow over the carb. Some use baffles, some the tube mod, some a velocity stack.

Reply to
Jim P.

PolyTech Forum website is not affiliated with any of the manufacturers or service providers discussed here. All logos and trade names are the property of their respective owners.