Home | Classifieds | History | Technical | Links | Store | About Us | Email
Topics Topics Edit Profile Profile Help/Instructions Help Member List Register  
Search Last 1|3|7 Days Search Search Tree View Tree View  

Prop rpm

Old Marine Engine » Gray Marine Gas Engines - 4, 6, and 8 cylinder » Prop rpm « Previous Next »

Author Message
Top of pagePrevious messageNext messageBottom of page Link to this message

Paul
Visitor
Posted on Tuesday, July 20, 2004 - 08:13 pm:   Edit Post Delete Post View Post/Check IP Print Post    Move Post (Moderator/Admin Only)

GM 4-91 (25Hp, 4 cyl, ~1957). How can I know the prop speed? I have the engine RPM, there's only 1 forwared gear, but I don't know the reduction (yet).
Top of pagePrevious messageNext messageBottom of page Link to this message

andrew
Moderator
Username: andrew

Post Number: 823
Registered: 11-2001


Posted on Tuesday, July 20, 2004 - 08:57 pm:   Edit Post Delete Post View Post/Check IP Print Post    Move Post (Moderator/Admin Only)

Mark the flywheel and mark the shaft. Rotate the flywheel one full rotation (or more) by hand and then measure the relative amount of rotation of the shaft to establish the "gear ratio".
Top of pagePrevious messageNext messageBottom of page Link to this message

Paul
Visitor
Posted on Wednesday, July 28, 2004 - 07:53 am:   Edit Post Delete Post View Post/Check IP Print Post    Move Post (Moderator/Admin Only)

Well that was a silly question. It's 1:1 flywheel to prop shaft in forward gear.
Here's another silly question. How do I figure, or find the graph, for the torque at typical cruising RPM of 1200? (the 25Hp rating is at 2000 rpm).

Add Your Message Here
Post:
Bold text Italics Underline Create a hyperlink Insert a clipart image

Username: Posting Information:
This is a public posting area. Enter your username and password if you have an account. Otherwise, enter your full name as your username and leave the password blank. Your e-mail address is optional.
Password:
E-mail:
Options: Automatically activate URLs in message
Action:

Administration Administration Log Out Log Out   Previous Page Previous Page Next Page Next Page

Home | Classifieds | History | Technical | Links | Store | About Us | Email
&copy 2005 OldMarineEngine.com, P.O. Box 188, Forest Dale, VT 05745-0188 • Phone: 802-247-4864 • All rights reserved.
   Marine Engine Seloc Repair Manual Lookup Tool

marine gas engine repair and restoration