2 inches in pitch lower the rpm by 300

Discussion in 'Diesel Engines' started by mohamed atia, Nov 9, 2009.

  1. mohamed atia
    Joined: Oct 2009
    Posts: 20
    Likes: 1, Points: 0, Legacy Rep: 13
    Location: egypt

    mohamed atia Junior Member

    Dear all ,
    i read in this great forum that every 2 inches in pitch lower the rpm by 300?
    what does it mean?

    sorry I want to understand the relation between the prop diameter and pitch and also the engine rpm?

    thanks for your last help and also coming
     
  2. gonzo
    Joined: Aug 2002
    Posts: 15,246
    Likes: 949, Points: 123, Legacy Rep: 2031
    Location: Milwaukee, WI

    gonzo Senior Member

    That works for props on the 12-18 inch range. A change of 2 inches pitch will vary maximum RPM by about 300.
     
  3. mohamed atia
    Joined: Oct 2009
    Posts: 20
    Likes: 1, Points: 0, Legacy Rep: 13
    Location: egypt

    mohamed atia Junior Member

    i want to know how come the change in prop affects the engine rpm?
    moh.ayad
     
  4. gonzo
    Joined: Aug 2002
    Posts: 15,246
    Likes: 949, Points: 123, Legacy Rep: 2031
    Location: Milwaukee, WI

    gonzo Senior Member

    Do you understand what pitch is?
     
  5. CDK
    Joined: Aug 2007
    Posts: 3,324
    Likes: 148, Points: 63, Legacy Rep: 1819
    Location: Adriatic sea

    CDK retired engineer

    The statement is out out context, hence meaningless. Read the whole post and perhaps you will understand. If not, forget about it.
     
  6. mohamed atia
    Joined: Oct 2009
    Posts: 20
    Likes: 1, Points: 0, Legacy Rep: 13
    Location: egypt

    mohamed atia Junior Member

    pitch is the distance that the blade go when it run 360 degree.
    that what i learned before
     
  7. gonzo
    Joined: Aug 2002
    Posts: 15,246
    Likes: 949, Points: 123, Legacy Rep: 2031
    Location: Milwaukee, WI

    gonzo Senior Member

    OK. The higer the pitch, that is the more it advances in one turn, the more load it puts on the engine. More load=less RPM. A pitch change is equivalent to a gear change. Higher pitch=lower gear ratio
     
  8. Frosty

    Frosty Previous Member

  9. mohamed atia
    Joined: Oct 2009
    Posts: 20
    Likes: 1, Points: 0, Legacy Rep: 13
    Location: egypt

    mohamed atia Junior Member

    dear frosty:
    about ur reply.
    i ask this question because i read the information in this forum and specially from MR/GONZO that i respect more for his reply

    thanks for ur time and thanks alot for ur help
     
  10. Frosty

    Frosty Previous Member

    Just cant help some people ,--I guess he likes talking to Gonzo. Im glad I took my avatar down now.
     
  11. gonzo
    Joined: Aug 2002
    Posts: 15,246
    Likes: 949, Points: 123, Legacy Rep: 2031
    Location: Milwaukee, WI

    gonzo Senior Member

    Does Egypt have censorship on the web? I was working in the Middle East, and they have so many filters that a lot of links don't work. It was really frustrating when you are used to free access.
     
  12. mohamed atia
    Joined: Oct 2009
    Posts: 20
    Likes: 1, Points: 0, Legacy Rep: 13
    Location: egypt

    mohamed atia Junior Member

    no sir,
    i think we haven't any filters like this .if this done the most sites will be filtered are **** ones.i want to know when and where you were work in egypt?

    moh.ayad
     
  13. gonzo
    Joined: Aug 2002
    Posts: 15,246
    Likes: 949, Points: 123, Legacy Rep: 2031
    Location: Milwaukee, WI

    gonzo Senior Member

    I was in Oman and Dubai not Egypt. They have lots of filters.
     

  14. mohamed atia
    Joined: Oct 2009
    Posts: 20
    Likes: 1, Points: 0, Legacy Rep: 13
    Location: egypt

    mohamed atia Junior Member

    sorry frosty,i respect every one here but this information was said by gonzo and this is the reason of my interest in his reply but off course i respect ur help

    and about dubai and oman really they have those filters and in egypt we haven't

    thanks for you sirs
     
Loading...
Forum posts represent the experience, opinion, and view of individual users. Boat Design Net does not necessarily endorse nor share the view of each individual post.
When making potentially dangerous or financial decisions, always employ and consult appropriate professionals. Your circumstances or experience may be different.