#11
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Re: rebuilding/repowering a 20' center console
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A bracket is typically worth about 3 mph in top speed. I've seen 49.5 mph on gps on my boat with a full tank of fuel and just me on board with a 4B 14x21" pitch prop. Could probably get more with the right 3 blade prop, but they don't have enough stern lift for my stern heavy rig. Also think the motor could go a little higher but I'm already in the top hole and cavitation plate is about 3.5" above the keel. I'm not that interested in top end anyway, and normally run a 15x15 4B PowerTech that jumps on plane very quickly at less than half throttle with a total weight of about 4000 lbs! That V-20 is a very hard riding hull, one of the worst built I've ever seen (I personally know of 5 that have busted up running offshore here), and I don't think it's nearly as efficient as a SeaCraft. From my experience, I think a properly rigged SC20 can easily break 50 mph with about 175 hp on a bracket.
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'72 SeaFari/150E-Tec/Hermco Bracket, owned since 1975. http://i188.photobucket.com/albums/z...Part2019-1.jpg |
#12
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Re: rebuilding/repowering a 20' center console
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1975 SF18/ 2002 DF140 1972 15' MonArk/ 1972 Merc 50 http://i833.photobucket.com/albums/z...photos/SC3.jpg |
#13
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Re: rebuilding/repowering a 20' center console
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With my Seafari, (which is heavier than a MA or SF), this motor, and no bracket, once I got it propped right, even with my ablative bottom paint I could just touch 54 mph in the right conditions. I believe with a Hermco bracket I could have achieved 57, possibly 58 mph. (The motor did suck fuel at a prodigious rate, though, at anything over 5600 rpms) The current Etec 175 reportedly actually produces between 188 and 195 hp at the prop. (The Etec 150 about 165 hp). So with the right prop, a nose cone and a bracket, it should easily reach 55 mph on a 20' SF with a slick bottom. And cruise at over 3.5 mpg, too. Of course, with my 90 Optimax, I still cruise at 24 mph, but get over 5 mpg
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Common Sense is learning from your mistakes. Wisdom is learning from the other guy's mistakes. Fr. Frank says: Jesus liked fishing, too. He even walked on water to get to the boat! Currently without a SeaCraft (2) Pompano 12' fishing kayaks '73 Cobia 18' prototype "Casting Skiff", 70hp Mercury |
#14
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Re: rebuilding/repowering a 20' center console
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I thought the 150XR4s were all 2.4L. My '91 XR4 is. I just assumed the XR2s were 2.0L, the XR4s were 2.4L and the XR6s were 2.5L. Not so? Dave
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Blue Heron Boat Works Reinventing the wheel, one spoke at a time. |
#15
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Re: rebuilding/repowering a 20' center console
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Of course, there exists the possibility that I'm completely wrong. Tim (BigShrimpin') would be the authority on this. I know a lot more about the pre-'88 Merc inlines.
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Common Sense is learning from your mistakes. Wisdom is learning from the other guy's mistakes. Fr. Frank says: Jesus liked fishing, too. He even walked on water to get to the boat! Currently without a SeaCraft (2) Pompano 12' fishing kayaks '73 Cobia 18' prototype "Casting Skiff", 70hp Mercury |
#16
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Re: rebuilding/repowering a 20' center console
I just took some photo's, how do I post them now?
Thanks, John |
#17
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Re: rebuilding/repowering a 20' center console
John, you first need to open up a free internet account on some site (Photobucket is a good one many of us use) that allows you to upload the pictures from your computer to that site. It's actually a good way of backing up important pictures to prevent loss due to a hard drive crash, etc., and you can then get to them from any computer with internet access. Checkout this post from Capt. Chuck in the Photos section that provides step by step instructions. It's real easy once you learn the process. Denny
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'72 SeaFari/150E-Tec/Hermco Bracket, owned since 1975. http://i188.photobucket.com/albums/z...Part2019-1.jpg |
#18
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Re: rebuilding/repowering a 20' center console
Thanks for the input on photo's, I just set up a photobucket account,here's a couple of pictures
[image]http://i1190.photobucket.com/albums/z454/jfc6866/th_100_0296.jpg?t=1297280175[/image] [image]http://s1190.photobucket.com/albums/z454/jfc6866/?previewTheme=84&track=interstitial&previewCancelU rl=http%3A%2F%2Fs1190.photobucket.com%2Falbums%2Fz 454%2Fjfc6866%2F#!cpZZ2QQtppZZ20[/image] |
#19
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Re: rebuilding/repowering a 20' center console
Lets try again
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#20
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Re: rebuilding/repowering a 20' center console
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