1974 20SF Rework / Modification

PackRat · #1 12-16-2009, 12:33 PM

First, as many others have done, want to reiterate how great this site is as far as pics, ideas, and quality collection of info one place.

I purchased a 20SF I/O in Sept. that had been converted to a inboard (351 PCM) in '94. Intent is to convert to a outboard w/bracket. Lot of work to go and just getting started so I guess the clock starts now on how long it's going to take - with two kids and another boat , it's going to be a while . Deck and transom both need to be replaced as well as correcting of things undone by the inboard install. Engine is out and sold and just got the boat squeezed in my garage - starting to remove harware, etc. There will be some items that I don't plan on using so I will add a seperate post with pics in case anyone might be interested. Photos below.

http://i969.photobucket.com/albums/a...Fwdreduced.jpg

http://i969.photobucket.com/albums/a...ilereduced.jpg

http://i969.photobucket.com/albums/a...ernreduced.jpg

http://i969.photobucket.com/albums/a...earreduced.jpg

http://i969.photobucket.com/albums/a...olereduced.jpg

http://i969.photobucket.com/albums/a...inereduced.jpg

http://i969.photobucket.com/albums/a...outreduced.jpg

PackRat · #2 12-16-2009, 12:40 PM

Amateur! - let's try pics again

foolharty · #3 12-16-2009, 05:33 PM

wow, she really sat low...

workinpr0gress · #4 12-16-2009, 05:38 PM

why did someone ever do that...that had to kill the ride of that pretty old boat....it'll run GREATTTTT with a bracket

Blue197320 · #5 12-16-2009, 07:37 PM

i think its pretty cool to see one like that. only because i havent seen one like that before.

thehermit · #6 12-16-2009, 07:45 PM

Wow...if nothing else that sure is impressive that they fit that rig in a 20SF. Good luck with your restore and post up plenty of pix

77SceptreOB · #7 12-16-2009, 10:05 PM

For a minute there, I was thinking that was the smallest 23 inboard SF I've ever seen. And where was the prop cut-out. Then I noticed the header 20 foot......duh.....

BigLew · #8 12-16-2009, 10:21 PM

What surprises me is that it apparently does not go through a V-drive. It really is a straight in-board!

PackRat · #9 12-16-2009, 11:21 PM

BigLew, correct, was a straight inboard with the fuel tank under the old I/O motor box...I actually took it for ride before putting the motor up for sale and it seemed to ride fine although I have no comparison as I've never been on another 20. Maybe a little slow for RPM's/fuel compared to the original I/O or what it would be with OB - had no GPS or speed indication so would only be guessing - probably upper 20's @ 3200 RPM (1.5:1 gear). Couple times bumped the RPM's up by a few hundred and the boat really flew and handled fine but wanted to take it easy on an unknown engine. Any more details will be a mystery now....

BigLew · #10 12-17-2009, 10:37 PM

That doesn't surprise me at all.

Under the circumstance, I doubt seriously the prop pitch, etc. was better than a "best" guess; and not being a V-drive, you had to probably increase the downward angle of the shaft/prop more than optimal. The other thing our outboard brethren seem not to appreciate is that the weight of an inboard acts as a terrific ballast. It really gives a solid predictable reaction to the hull's behavior in a sea and when it settles, it does so more predictably than an outboard which is, generally, less predictable given the leverage arm of forces (ect.) that influence it vs. simply the size and direction of the wave in question. The other part of this is that the inboard configurations generally are twice the weight/HP than the outboard thus the reduction in top end speed.

Oh well, just more proof to the adage, "You have to pay to play!"