repower

mjquatt · #1 04-17-2006, 07:11 PM

I am trying to finish the restoration of a 1976 20' SC and would like some imput on power. The boat will have no top. I am going to use a 55 gal belly tank and want to get the best range possible without compromising performance too much.The options I am considering at this point are Suzuki 4 strokes either the 140, 150 or 175. If anyone has any imput and some numbers to boot it would help a great deal.

Bigshrimpin · #2 04-17-2006, 08:39 PM

"55 gal belly tank" => a belly tank is not going to use the space efficently. Which 20 do you have? MA's can fit a 70 gallon tank.

mjquatt · #3 04-18-2006, 10:39 PM

My '76 is not a MA. The 55 gal belly tank is a stock tank from West Marine. I would like to go larger but do no have any outlets for fabrication. The original tank was 48 gal.

caper · #4 04-19-2006, 03:14 PM

If you keep the Seacraft scuppers and original deck height the 20'SC is sensitive to motor weight. That said; 140 horsepower will give about 40 mph w-out a top, 150 probably 42 or 43 mph.

mjquatt · #5 04-19-2006, 09:45 PM

Thanks for the numbers. I will keep the floor height the same but am looking at a small design change with the scuppers.

Bigshrimpin · #6 04-20-2006, 04:28 PM

MJ - what are the dimensions of that 55 gallon belly tank from west marine? I don't recall west selling any tank of that capacity which will fit into the 20ft seacraft hull.

mjquatt · #7 04-22-2006, 12:40 PM

West Marine offers two 55 gal belly tanks. One is by Todd and the demensions are 51"L 25 1/2"W and 16"H. The other is an aluminum tank and it is 48 1/2"L 24"W and 9 1/2"H. Both tanks are listed on page 264 of the '06 catalog.

Bigshrimpin · #8 04-22-2006, 12:47 PM

I'm 99.9% sure that neither of those tanks will fit under the floor of the seacraft sf20 w/o raising the floor several inches or grinding down the center stringer.

Bigshrimpin · #9 04-22-2006, 10:43 PM

23 1/4" x 90 1/4" x 8 These are the dimensions of my 70 gallon tank in the stock 20 MA.

Do a search on the board for fuel tank Dimensions or maybe someone can post their SF dimensions.

This is hermco's tank on his SF 20.

mjquatt · #10 04-23-2006, 12:15 PM

Thanks for the demensions on the 70 gal tank. I still have the floor out of my boat so if I can find someone to fabricate a tank for me I will use that one.