Motor RPM ?

[Coyotes-R-Us]

Just looking around and it appears that sustained RPM on my 1600cc
Is about 4500 rpm and caution should be taken a 5000.
My variable drive lets me get 4500 with the prop I have.
After a short time the prop reduction catches up and I don't get the 1 to 1 I hoped for
But at 4000 it looks to be about 3000 at the prop.
Would you run your air cooled motors at 4000/4500 all day long ?
Looking at serval airplane sights I may be getting 215 to250 pounds of thrust.
Sound about right ???

[Corky]

VWs are different than the 084...Too many rpms for the 084....You could most likely get away with 4000rpm but I'd still run some temp gauges to monitor what's going on that will tell you if the engine likes it or not...But 1to1 and that size/style wooden prop spinning at 4 grand I'm sure is too much...Engine condition has a lot to do with where the thrust falls but it seems to be in the ballpark with your calculations....

[Coyotes-R-Us]

"at 4000 it looks to be about 3000 at the prop"
The Prop does catch up with the motor some and I will probably get t to
cruise at something under 4000.
What do you plan for rpm's on your 084's ?

[Corky]

The rpms for the 084 with the circle s redrive are shooting for 3600-3800 engine{that's about 2248 prop speed at 1.69} and the direct drive is around 2600-3100 rpms...Keep in mind the 084 is limited by the oiling system and it's lack of cooling for any higher performance in it's stock,unshielded form...The VW with all the shields like you've got plus the cooler temps will give a distinct advantage for what you're doing there..

[Papee]

Most props have a designed limit of 3100 rpm but the stop pushing at anything over 2800 rpm. Pushing any prop past 2800 really doesn't do much good. The ultra prop I had on actually slowed after about 2800.