| Author |
Message |
    
mgangell
Visitor
| | Posted on Sunday, September 20, 2015 - 11:24 pm: | 
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I am trying to locate engine/boat information necessary to determine proper prop size. I have a 1948 Gray Marine Phantom Six-104 engine (out of the boat). A data table from Motor Boating magazine states this engine could have a 1:1.5 or 1:2 gear ratio. It is hard for me to crank the engine to see prop rotation. Is there another way to determine the ratio? Markings or numbers? |
jim g
Member
Username: jim_g
Post Number: 8
Registered: 05-2013
| | Posted on Monday, September 21, 2015 - 07:05 am: |
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Can you post a picture? I work on a lot of these motors and can usually tell from a picture of the trans. |
mgangell
Visitor
| | Posted on Monday, September 21, 2015 - 09:55 pm: |
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Jim - Thanks for taking a look. I've attached a picture here. |
mgangell
Visitor
| | Posted on Monday, September 21, 2015 - 10:13 pm: |
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Here is another picture. |
jim g
Member
Username: jim_g
Post Number: 9
Registered: 05-2013
| | Posted on Monday, September 21, 2015 - 11:11 pm: |
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You have a 1 to 1 direct drive gear box. More then likely its a paragon trans. Its either an OKE or 1XE model. If you pull the cover of the trans and look at the drum up at the front edge Paragon will be stamped into the drum and it will have the model stamp there also.
Depending on the boat its going into it would probably run around a 12" diameter prop.
Also most of these engines were right hand drive. The only left hand engines they made usually went into twin engine hulls. |
mgangell
Visitor
| | Posted on Tuesday, September 22, 2015 - 12:05 am: |
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Jim - Thanks for the info! There was a 13 x 13 RH prop on the shaft. In addition, I found an 11 x 11 RH prop included with the boat. I don't know why a 11 x 11 would have been used. It's interesting that the Specs in MotorBoating stated that these engines came with either a 1.5 or 2 ratio. Looks like not in this case.... |
jim g
Member
Username: jim_g
Post Number: 10
Registered: 05-2013
| | Posted on Tuesday, September 22, 2015 - 12:13 am: |
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You could get different gear ratios to fit your application. If you were putting it in a 23 foot or bigger boat you would want a reduction drive. I have several Chris Craft 105 hp flat heads that have a 1.5 to 1 ratio that came out of a 40 chris craft cruiser. A direct drive would be for a runabout application and a reduction drive would be for a much heaver boat. |
mgangell
Visitor
| | Posted on Tuesday, September 22, 2015 - 12:30 am: |
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Okay. That makes some sense. The engine is for a 17.5' 1948 Century Resorter. Thanks again! |
