.20FP vs .25FX

Looking to upgrade from a .20fp to .25fx, any idea how much more powerful is the fx than the fp ?

Reply to
lennyk
Loading thread data ...

About double. The 25FX will spin the same props a lot faster and be able to spin larger props at the same speed.

Reply to
Paul McIntosh

Considerably, but spend a few more dollars and buy the .32 FX, unless you are limited by contest rules.

Same size, nearly the same weight and considerably more powerful than the .25 FX.

Ed Cregger

Reply to
Ed Cregger

tried out the .25fx today with a ma 9x5 vs a .20fp with 8x4 difference was like night and day.

Reply to
lennyk

Like night and day? Did one of them not work? Which was night and which is day?

Reply to
Sport Pilot

Clues: The .25 FX in addition to 25% more displacement has ball bearings. The .20FP is just an anemic version of the 40FP - good engine for the money, but it just won't compare with the more expensive ball bearing offerings.

Red S.

Reply to
Red Scholefield

Reply to
JACK

well in a 2.5 pound profile airplane, the .20fp(8x4) has no vertical at all, the .25fx(9x5) takes the plane out of sight. best part is no leaky fuel in front from the bushings.

Reply to
lennyk

Actually ball bearings don't make it go. Lots of older bushing engines ran as well as ball bearings. .05 displacement isn't so great that a .20 can't overcome that power. I was actually commenting on his lack of clarity, not confused about the engines.

Reply to
Sport Pilot

Don't you think the FP was a little underpropped? Unless it was an 8-4 three blade. FP's make their power at lower speeds, a 9-4 would have been a better selection? Still would have been less thrust though.

Reply to
Sport Pilot

I have both engines. .25fx is a really powerful engine and the .20 fp just runs. :) mk

Reply to
MK

And we're all surprised at this? WOW!

Reply to
David

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.