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1975 f25 with 318 4brl. gal. per hr.
Posted: Wed Sep 13, 2006 10:37 pm
by martin
Can any body tell me about GPH. use I just bought this thing and I need to bring her home 25 GAL. tank makes me wonder how far I can go on a tank.
So I can plot fuel stops on the way I thought 10GPH. might be close but 2.5 hr. on a tank seams low.
Guess 1.5-2mpg (not gph)
Posted: Thu Sep 14, 2006 12:28 pm
by rossjo
I would guess about 20-22mph @ 8gph = 2.xmpg ....
To be safe - guess 1.5mpg (not gph) - and take along (2) 5 gallong Jerry bottles (plastic - not metal) of gas just in case.
My Fiberglass Chaparral 24 Express Fisherman w/ a 454 and Bravo Outdrive runs most efficently @ about 21mph @ 7gph = 3mph (it wIll go 50, but then its 30gph).
Posted: Thu Sep 14, 2006 4:58 pm
by martin
Thanks for the info I just thought this thing would have more range than that I gues I can put a bigger tank in or name her NO LEGS.
Posted: Thu Sep 14, 2006 9:01 pm
by chucka
Martin,
25 Gal. is a tiny fuel tank for this boat. Are you sure it's that small? I thought a 60 Gal fuel tank and 25 gal water tank were standard (as described in the ad below for a 1974 F25)
http://adcache.boattraderonline.com/6/2/4/85117624.htm
You can get a reasonable estimate by measuring the tank and calculating the volume, LxWxH [inches] = volume [cubic inches] divided by 231 cubic in per Gal = approximate capacity in Gallons. You aren't allowing for the thickness of the tank or air space at the top so subtract a little from the final answer.
I replaced the tank on my 1975 F26 a couple of years ago. The rough dimensions are (from memory) 53" L x 22" W x 15" high = 17,490 cu-in divided by 231 cu-in/gal = about 75 gallons. By comparison, West marine has a 26 gal aluminum tank with dimensions of about 36.4" x 16.4" x 10"
I'm a slow poke with a 318 in my F26. I put along at about 8 knots at 2000 RPM burning about 3.5 gph or roughly 5.5 gph at 2400 RPM & 10 knots. Figures are approximate.
speed......................................range
knots........RPM....gph.....mpg..on 60 gal
...8..........2000....3.5......2.7.......165
..10.........2400....5.5......2.2.......131
Let us know if you find out anything more.
Good Luck,
Chuck
Posted: Fri Sep 15, 2006 5:35 pm
by martin
thanks chuck I used to manufacture volumetric provers and went to the boat last night and put a tape on the tank. You are correct I'm glad to know that also thanks for the further info on est. gph. 5.5 is good news and 10.0 knots is just fine it's not a speed boat now I can relax on my trip it's been a wile.
thanks for the help martin