In a 2:1 ratio, wouldn't the "2" be the number of times the engine (drive shaft) turns and the "1" be the number of times the prop turns? Seems like you had it backwards.
Lol just watched it back and you're right lol I don't know how we missed that SMH! But I'm not rerecording it though lol I'll just pin this to the top :) Thank you!
I wish I could, but you can't edit the video once it's uploaded to youtube. We'd have to edit it, and upload it as a new video, which, you've seen it already so I'll just pin this comment to the top :) Thanks for the pass ;)
Thanks. I hope it didn't come across as trolling. Your videos are always very helpful. Just wanted to make sure I was thinking straight. @@BornAgainBoating
backwards on the gear ratio in this video, but yeah, rpms are what make a boat go, giving the prop more bite makes a higher torque requirement from the engine, now how much torque can the prop require and how fast can you spin it? ie; how many rpms, that's how you go fast along with reducing drag.
It actually does. If you calculate the rpm to mph ratio to the gear ratio. To height ratio unless the vessel reaches the calculated speed then even at peek rpm the boat won’t be traveling faster than the hp of the engine can handle. So every time you add say the same engine and cruise at the same rpm it is going to be moving faster each time because they share the load of weight rpm to hp ratio
Also, you should talk about the pitch more. You only talked about the diameter, where as the pitch of the propeler is almost equally important, it determines the speed at the expense of thrust. More pitch more speed and less thrust.
as a marine tech , I agree. Of course most people ( even where I am at) want mpg/fuel econ. Repowered a cat with 3 of the new yama 350s and the owner gets 96 more miles per tank then the 300s they did have. IMO if you are in it for speed...more often then not you don't care about $. Most boats i work on/repower are 4x outboards 400+ each so maybe my mind has gone blank....
Interesting! It’s literally the same thing as my RC traxxas Xmaxx. Lower kv motors allow lower gear ratios without overheating issues. And the gear ratio is specifically related to the pinion and spur gears.
Seems like some boats have a hull design that only goes so fast and trying to go much past its top speed its easier for the prop to blow out then push the boat faster.
At the same efficiency, an engine with higher horsepower is consuming a linearly proportional larger amount of fuel at the same rpm. So if a 300hp and a 150hp have the same effiency, the 300hp will consume twice as much gasoline when they are both running at 3000rpm.
Actually, this might be wrong. Horsepower is specific to rpm, so if both motors are not at the same fraction of their rated horsepower at the same rpm, what I said earlier wouldn't be true.
@@alexanderx33huge respect for admitting you might be wrong! Your example is good but it is better applied at max rpm because then the motor will be making its max hp (assuming its under full load at max rpm) and then you can make the comparison between 150hp and 300hp
@@andronclock1 Actually you have to look at the power curve, you need to be at WOT AND have the prop pitched such that you are at 150 HP/ 300HP in the curves respectively. If you over pitch or under pitch you move up or down the power curve.
The diameter of tge prop has less "leverage" impact than pitch, actually it has none because the larger diameter the prop the faster the prop tips are spinning which is effectively like running in a higher gear.
Not really an apples to apples comparison; but the remote control model speed record is held by a glider. The team working on breaking the existing record came to the conclusion that the engine was just slowing the plane down and so left it off! The plane remains airborne by slope soaring off a high cliff.
I never have understood how a 250hp motor was better than a 200hp motor with the same prop and gear ratio. A propeller can only grab so much water and push it much like a car tire. Put to much power on a tire and it breaks loose and spins. I can’t grasp how a propeller is different so the extra hp feels like a waste of money. What am I missing here?🤷♂️
more power does mean more speed if you can utilize it correctly) go with lower gear ratio and higher pitch prop and you will get more speed...if you have enough power to spin it to nominal rpm range)
This video sux. The thickness of a ratchet handle has NOTHING to do with torque. Neither does the size of the propeller. The prop blade isn’t what makes torque the engine and gearing does. The blade diameter and pitch is how the torque is applied to the water, the grip on the water and how far the theoretical distance the prop moves forward per revolution. Gear ratio is an engine torque multiplier.
You can put 600hp on a crappy slow hull design and it would still be slow. Or you can put a 250 on a fast hull design and it will still be fast. Hull design is the key. There isn’t a perfect hull design. Stability, dryness of ride, ability to take rough water, top speed, or maneuverability. Take a percentage of all but wont ever get a perfect hull design that peaks all scenarios. Typically a fast hull doesnt like rough conditions but if it does then you’ll sacrifice stability and dryness of ride.
This guy does not know what he's talking about. With a 2:1 ratio as an example, the pinion will make two revolutions to one revolution of the prop shaft. A numerically larger first number like 2.5:1 would be considered a lower gear because the prop will turn slower and speed will be lower but the torque will be higher. A numerically smaller first number such as 1.5:1 would be considered a higher gear because the prop will spin faster and produce more speed but less tourque.
I'm sorry. I grew up in a generation that would ask. How could you NOT KNOW that. The fact that you can have a successful view rate on such a simple concept is scary. It's not like we're talking about programming encapsulation or polymorphisms....it's a gear ratio. Oh well ...
In a 2:1 ratio, wouldn't the "2" be the number of times the engine (drive shaft) turns and the "1" be the number of times the prop turns? Seems like you had it backwards.
Saw the same thing. Should be edited as not to confuse others. This channel is the best though so I’ll let it slide.
Lol just watched it back and you're right lol I don't know how we missed that SMH! But I'm not rerecording it though lol I'll just pin this to the top :) Thank you!
I wish I could, but you can't edit the video once it's uploaded to youtube. We'd have to edit it, and upload it as a new video, which, you've seen it already so I'll just pin this comment to the top :) Thanks for the pass ;)
Thanks. I hope it didn't come across as trolling. Your videos are always very helpful. Just wanted to make sure I was thinking straight.
@@BornAgainBoating
what.the.hell.does.that.mean
More engines ,more drag. Most of us don’t worry about it,we can barely afford 1 engine
I just wanted to say that this video is awesome. I know you put a lot of work into this and it shows. Good job, brotha!
I appreciate that! Thanks man.
Very useful explanation, perfectly managed! Thanks for sharing and greetings from Italy 👌
You're very welcome!
2:1 ratio is how many times the engine spins per the output shaft of the gear case. You need to research info more prior to making videos.
Amazing explanation. Now back to getting my boat back on the water and propped out correctly.
Thanks. Yea, you should!
backwards on the gear ratio in this video, but yeah, rpms are what make a boat go, giving the prop more bite makes a higher torque requirement from the engine, now how much torque can the prop require and how fast can you spin it? ie; how many rpms, that's how you go fast along with reducing drag.
Can you show us what parts make the grinding sounds when putting into gear?
It actually does.
If you calculate the rpm to mph ratio to the gear ratio.
To height ratio unless the vessel reaches the calculated speed then even at peek rpm the boat won’t be traveling faster than the hp of the engine can handle.
So every time you add say the same engine and cruise at the same rpm it is going to be moving faster each time because they share the load of weight rpm to hp ratio
Also, you should talk about the pitch more. You only talked about the diameter, where as the pitch of the propeler is almost equally important, it determines the speed at the expense of thrust. More pitch more speed and less thrust.
as a marine tech , I agree. Of course most people ( even where I am at) want mpg/fuel econ. Repowered a cat with 3 of the new yama 350s and the owner gets 96 more miles per tank then the 300s they did have. IMO if you are in it for speed...more often then not you don't care about $. Most boats i work on/repower are 4x outboards 400+ each so maybe my mind has gone blank....
Interesting! It’s literally the same thing as my RC traxxas Xmaxx. Lower kv motors allow lower gear ratios without overheating issues. And the gear ratio is specifically related to the pinion and spur gears.
Excellent explanation thank you for sharing!
You're welcome.
Seems like some boats have a hull design that only goes so fast and trying to go much past its top speed its easier for the prop to blow out then push the boat faster.
Your reduction discussion is backwards. The first number is how many times the engine goes around to rotate the prop once.
At the same efficiency, an engine with higher horsepower is consuming a linearly proportional larger amount of fuel at the same rpm.
So if a 300hp and a 150hp have the same effiency, the 300hp will consume twice as much gasoline when they are both running at 3000rpm.
Actually, this might be wrong. Horsepower is specific to rpm, so if both motors are not at the same fraction of their rated horsepower at the same rpm, what I said earlier wouldn't be true.
@@alexanderx33huge respect for admitting you might be wrong! Your example is good but it is better applied at max rpm because then the motor will be making its max hp (assuming its under full load at max rpm) and then you can make the comparison between 150hp and 300hp
@@andronclock1 Actually you have to look at the power curve, you need to be at WOT AND have the prop pitched such that you are at 150 HP/ 300HP in the curves respectively. If you over pitch or under pitch you move up or down the power curve.
I have no idea how I understood all that but I did. Thank you!
You're welcome!
Thank you for putting this out there, I am still trying to figure out my 1994 merc 60 hp on a 17ft logic cc. Can't quite get it right!
Thank you
Is Yamaha ring free plus good for burning of carbon?
Excellent presentation
Thanks a lot
The diameter of tge prop has less "leverage" impact than pitch, actually it has none because the larger diameter the prop the faster the prop tips are spinning which is effectively like running in a higher gear.
Wait. Diesel is 279 in florida its friggan 450 in miane
Greatest marine related video ever.
Thanks Man.
Not really an apples to apples comparison; but the remote control model speed record is held by a glider. The team working on breaking the existing record came to the conclusion that the engine was just slowing the plane down and so left it off! The plane remains airborne by slope soaring off a high cliff.
Very use full but not all people they can catch your talking speed especial when we learn
Noted!
I never have understood how a 250hp motor was better than a 200hp motor with the same prop and gear ratio. A propeller can only grab so much water and push it much like a car tire. Put to much power on a tire and it breaks loose and spins. I can’t grasp how a propeller is different so the extra hp feels like a waste of money. What am I missing here?🤷♂️
thank you
You're welcome
more power does mean more speed if you can utilize it correctly) go with lower gear ratio and higher pitch prop and you will get more speed...if you have enough power to spin it to nominal rpm range)
Merci beaucoup ❤❤❤❤❤
Latest I checked more power DOES equal more faster
This video sux. The thickness of a ratchet handle has NOTHING to do with torque. Neither does the size of the propeller. The prop blade isn’t what makes torque the engine and gearing does. The blade diameter and pitch is how the torque is applied to the water, the grip on the water and how far the theoretical distance the prop moves forward per revolution.
Gear ratio is an engine torque multiplier.
fun fact: drag
You can put 600hp on a crappy slow hull design and it would still be slow. Or you can put a 250 on a fast hull design and it will still be fast. Hull design is the key. There isn’t a perfect hull design. Stability, dryness of ride, ability to take rough water, top speed, or maneuverability. Take a percentage of all but wont ever get a perfect hull design that peaks all scenarios. Typically a fast hull doesnt like rough conditions but if it does then you’ll sacrifice stability and dryness of ride.
This guy does not know what he's talking about. With a 2:1 ratio as an example, the pinion will make two revolutions to one revolution of the prop shaft. A numerically larger first number like 2.5:1 would be considered a lower gear because the prop will turn slower and speed will be lower but the torque will be higher. A numerically smaller first number such as 1.5:1 would be considered a higher gear because the prop will spin faster and produce more speed but less tourque.
Better to have 2- motors 627hp less weight and little more hp.
This is way suzuki are always the slowest
I'm sorry. I grew up in a generation that would ask. How could you NOT KNOW that. The fact that you can have a successful view rate on such a simple concept is scary. It's not like we're talking about programming encapsulation or polymorphisms....it's a gear ratio. Oh well ...
I remember when was hysterical 😂😂😂 FJB
Your mommy drop you? Because that doesn’t make sense 😂
Get a life bud. It’s beyond tiring that people can’t even talk about gear ratios without someone throwing politics into it.