I have contacted both Cactus Aviation and Aircraft Int'l and asked them a simple question: what are the static thrust measurements of the 3W75US while using a 24x10 or a 26x10! Cactus wouldn't answer my question and AI quessed at 40-45 lbs! (hard to believe) Has anyone out there in gasser heaven measured this engine? Your replies would be most appreciated.
MP in Los Angeles

In all fairness to any motor manufacturer, company, or whatnot...

Static thrust is subjective:

- What Prop (yeah I know 26x10)
Fuchs, Menz, 3W, Mejslik, Bambula, Zinger, APC what???

- What altitude

- What temp & humidity

- what mufflers

- what oil / gas

Any number a vendor claims can only be tied to their special circumstances at the time of the test. That's why they do power curve analysis and thrust curves. Unfortunately, these things cost big bucks to find out with a competent testing organization.

Bottom line - if they give you a ballpark number, the numbers should be close. Otherwise, find a buddy with a 75 and hook up a fish scale.

What you want to know should be - "I have a 24 pound Extra 330S, what would you suggest I run?" That's when you get the appropriate answer.

You're correct and I agree with what you say, but like you also said, I'm looking for a "ballpark" answer and left the prop mfgr., alt., humidity, etc. to the replier. If I stated which airplane that was going to use this in, then it would be open to even more debate due to the wide # and styles of engines available for that plane. BTW, the plane in question is a Meister Zero, 108" at about 32 to 37 lbs.
Mike in L.A.

I am running a 26-11 cf prop on mine right now. It is a very great engine. Has alot of power. starts right up and runs VERY good.

I was wondering what is the best size and brand prop for this engine?

Have fun

My 75 would turn a 26x10 Menz @ 6450, which equates to 55.4lbs of thrust according to my thrust computer, I dont know what it turns a 24x10, my 3W 70 turns 24x10 @7100 for 48lbs of thrust, hope this helps.

My 75 will turn a 26-11 cf prop @ 5700-5800. I want to try a 26-10 on it. Sure seems like it doesnt put out 50lbs of thrust.

Need it to wind up better on the up lines and at slow speeds.

Need a littlel lighter load than a 26x11 carbon prop for it to wind up, try a 26x10 menz s, will let it wind up a little better. I even tried a mejzlik 24x12 3 blade, and was getting 6100rpm with that prop, but it likes the 26x10 a little better to me. My engine is well broke in, a lot depends on how much time is on the motor.

I was thinking about a 3W 26-10 wood prop. Have you tried this prop?

The engine is about a year old with alot of aerobatic flights.

I have not tried a 3W 26x10, they usually turn about 100rpm less than a menz because they are a little wider, but a very good prop.