New props - no test - now tested
Submitted by z00m on Sat, 2014-11-08 18:00
I fitted my new 4 blade Merc spitfire props today. Laid on the swim platform, raised the legs and did the spannering.
It was blowing pretty good and too choppy to do any serious testing so will have to wait for another day!
The suspense is killing me! ha ha.
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z00m
Posts: 1086
Date Joined: 10/05/14
Got to test the props this
Got to test the props this morning and I have to say they were a great choice. I could hold my favorite cruising speed of 24 knots at 3300rpm instead of 3600and I found the boat could plane at a lower speed. I couldn't hold 13 or 14 knots before. Flat out she went 34knots which is a speed we haven't reached before.
Devo1965
Posts: 120
Date Joined: 29/09/13
Interesting spec's
Happy with my 200 Yamaha, but would also be interested if changing from a 3 blade prop to 4 blade would slightly improve all round performance, cruise speed, fuel consumption, top end speed, bottom end planning speed, sound like has worked out ok for you zOOm.
Devo1965
z00m
Posts: 1086
Date Joined: 10/05/14
The 'secret' of the spitfire
The 'secret' of the spitfire props is supposedly to make sure you get the benefits of a 4 blade without losing the top speed of your existing 3 blade. So what they did was straighten the trailing edge and make the prop slightly smaller. If you buy a 14 x 23 as I did it is really a 13.8 x 23. The smaller size and straight trailing edge reduces the drag at higher speeds. I'll try and post a pic showing old and new in my original post.