Lille-bror

Not every engine My guess is that only 20% are ringed

imrob

iTrader: (7)

i belive that all of the os abl engine are ringed. think ts there la line that is not ringed. There four some have non and some are it depends on what you feel like paying for i guess the seem to be more pricy than non ringed. but what would happen if you change the pitch of the blade i do not know what it has stock for i dont own one now but that could change how it polls on the bearings of an car motor on the bench i would think.cause if you change the pitch on a plane it gonna pull more or less depending on which way you go.

bentgear

Ringed aircraft engines pretty much dominate after you pass 50's. For smaller it's hit or miss. I doubt anyone is turning 40,000 rpm's on the bench with a prop. Little thing called the sound barrier would come into play I would think, although I have not done the math yet (blade tip speed).

I know with the cut down prop the Hudy system at 15,000 rpm's it's screaming at you. The process normally is to start the break in on the bench to get the tedious part out of the way and then finish in the vehicle.

Lille-bror

Cool. I know the tip speed on a 120mm (4,72") prop are 251 km/t at 35000 RPM!
What's the pitch in inches on a prop used in bench break-in stands?
I know a guy who breaks-in engines with only the bench. I have to get it confirmed, but as I remember, the last tank of fuel is run by 80% throttle... Damn, the engines sounds horrible

Maximo

iTrader: (11)

that little prop on the Hudy bench will put more load on your engine then it will ever see in a vehicle on the ground.....pegged right out a strong engine can push 26 000 RPM Max on the stand.... the load from the prop is just too much for these engines to push further


Bench breakin all the way !!!!! without question the best way to breakin a engine !

bentgear

Good info Maximo, I have never had one mounted that I was willing to lean out and go full speed. My limit has always been 15,000 and then the alarm goes off. Set my lower limit at 6,500 and vary the RPM between those at the latter stages of breakin. Had to put my old Nomadio to use for something.

houston

iTrader: (96)

break in ? whats that?

just lean it out and run it!!


there are many ways to do break ins , some easy , some hard , find your particular method that suits you and stick with it as you will get better and better at perfecting your method each and every time , one thing i think we can all agree on is that you must use fuel with a fair amount of castor oil (6% min.) , do not over rev , use a varying heat method (heat cycle) and your engine should last a long time if properly tken care of

bentgear

Agh, come on Houston, spill the beans. I for one am glad one of the local hobby shops still stocks SIG castor.

houston

iTrader: (96)

beans? what are you talking about


i use byrons lube booster if i need extra castor works great

imrob

iTrader: (7)

so yo would just let it idle on the stand for like 3 tanks then put it in the car and do the second rule thing it it should be fine. was it designe too fully break in the engine or not is they man thing. as of now im just sticking with it in the car which seem simple enough to me. there seem to be too much of it work and dont work here but one guy said it cant seat the bearing i would think the prop spinnig around would be the same as the flywheel spinning would it not