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New question to an old topic 4 blade props

Posted: Wed Nov 20, 2013 8:54 pm
by Cmount
I am considering having a cup put into the new 4 blade props I put on this season. They are 17X14's. Does anyone have any thoughts how much of a cup I may want? The boat ran well this season, but I feel the props could have been slightly better. They seemed much better than my 16X16 3blades, but again seemed to me I could go a little further on the cup and get a little more out of her at 3100 rpms. I did pick up about 2 knots already at that RPM.

She really comes up to RPM's fast and takes a little to build the speed. No struggle for the engines at all, used to have much more struggle with the 3 blades. Any comments would be appreciated. They head to the shop on Friday.

Re: New question to an old topic 4 blade props

Posted: Wed Nov 20, 2013 9:09 pm
by prowlersfish
what rpm are you getting wide open ? What engines do you have .

Re: New question to an old topic 4 blade props

Posted: Wed Nov 20, 2013 9:13 pm
by Cmount
4000 4100 rpm chrysler 318's one is a 1977 and the other s a 1987.

Re: New question to an old topic 4 blade props

Posted: Wed Nov 20, 2013 9:25 pm
by prowlersfish
sounds like your right where you should be. Your right at 4000 rpm thats perfict for a 318 . If you add cup then you will drop below the rated rpm . I would leave it alone .



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Re: New question to an old topic 4 blade props

Posted: Wed Nov 20, 2013 10:31 pm
by ready123
No cup on mine and they seem to be perfect..... I would not cup yours.