Performance question F31 1971

guglielmo6160 · Post by **guglielmo6160** » Sun Nov 30, 2008 10:50 pm

hello all, I am planning my trip back to my marina with my recently purchased 71 F 31, I have twin healthy 302 fords, and was wondering what kind of speed I can expect without strainning my engines, rpm, etc,
I have a 70+ mile trip to set up and would like to have a time estimate on my arrival,
I am new to this model and enignes, etc, and would like some info on performance, I do not plan on pushing the engines at all, but realistically would like to keep em below 2500 rpms ,
also what type of fuel economy should I expect hourly
thanks in advance

dean price · Post by **dean price** » Sun Nov 30, 2008 11:20 pm

i have twin 318's. i feel that 19 knots on my f-31 hardtop is good , anything slower is off plane . it can do 30 knots if pushed . dean

dean price · Post by **dean price** » Mon Dec 01, 2008 1:04 am

being off the water a month and a half and getting older has fogged my memory. change my last post to read 1900 rpm and not knots. sorry dean

duchess · Post by **duchess** » Mon Dec 01, 2008 5:48 am

Dean congrats on the new purchase where are you leaving from and going to ?

guglielmo6160 · Post by **guglielmo6160** » Mon Dec 01, 2008 9:00 am

Hi, thanks,
I purchased the boat in South Jersey in Brick Township and its near the Point pleasant canal,
my marina is in Haverstraw NY wihich is North on the Hudson River approx 75 miles or so,
We had it all mapped out and gathered here at my home yesterday morning and of course with my luck the weather was no so good, we check the NWS Marine forecast and they called for a small craft advisory to take effect,with seas building to 4 to 7 ft, so being new to this boat and seeing the doubt in my crew, we decided to postpone the trip to this weds. We were all very dissapointed, however most of the trip would have been on the NJ coast and I just dont know those waters. I was thinking of a slower cruise speed , about 12 mph or so, but I realize she probably will not get up on plane, So according to what some have told me I should havno issues with 15 mph or so, I dont want to push my engines, or do something stupid. so can I expect at least 15? our of here, that would make my trip substantially shorter than I origianally thought
thanks in advance to all, would appreciate any info you can give me
Bill

guglielmo6160 · Post by **guglielmo6160** » Mon Dec 01, 2008 9:07 am

Does anyone have the Ford 302 engines, can you give me some info on them, I do have all the manuals but just to lazy to go through them at the moment and I found you guys here which I think is a better source of information anyway,,,lol
basically how much horsepower do they have, what can I expect speed wise from them at about 2300 -2500
they are tight and recently replaced.
also, my boat is a 1971 F31, which I just purchased, it is very clean, no visable rot anywhere, fairly well taken care of, just dirty from sitting around the marina, what do you guys think would have been a fair price in todays market for this type of boat,
here is a picture of it

http://www2.snapfish.com/slideshow/Albu ... =113707799

jddens · Post by **jddens** » Mon Dec 01, 2008 10:14 am

My F30 with Merc 350's cruises at 19 knots at 3100RPM. anything slower than about 16 knots and she starts to fall off plane. 2100 RPM's is about 9 knots or hull speed. Not sure about fuel consumption but I think around 10-12 GPH per engine at 3100RPM.....John

guglielmo6160 · Post by **guglielmo6160** » Mon Dec 01, 2008 10:40 am

wow, can that be right?? 20 gallons + per hour two engines?? that seems awfully high,

TADTOOMUCH · Post by **TADTOOMUCH** » Mon Dec 01, 2008 10:52 am

That is right. 3100 rpms at 19 kts = about 19 or 20 gal/hr or about 1 nautical mile per gallon of fuel.

I have a 1978 F-32 with twin Chrysler M360's at 250 hp each and she burns just about the same as the above post.

prowlersfish · Post by **prowlersfish** » Mon Dec 01, 2008 12:10 pm

Keep it below 7 knots or above 15 knots any thing in between you will be pushing water wasting fuel and straning the engines 3000-3100 rpm is a good number just above 1mpg sounds right run it below 6 knots you maybe get close to 2 mpg run it between 8 to 15 knots you will be lucky to get 1/2 mpg

And this is with a clean bottom . With a dirty bottom it burns a lot more fuel

rossjo · Post by **rossjo** » Mon Dec 01, 2008 10:00 pm

So clean your Bum before you go Laddie!

Peter · Post by **Peter** » Mon Dec 01, 2008 10:29 pm

boating is expensive.thoses numbers sound about right....ouch

guglielmo6160 · Post by **guglielmo6160** » Mon Dec 01, 2008 10:44 pm

boy you guys really know how to hurt a guy,,,,
your suppse to be all supportive and stuff,,,,lol, come on, lie a little
tell me its cheap and worth it,,,,,

LandVF36 · Post by **LandVF36** » Mon Dec 01, 2008 11:25 pm

Every moment on the water is worth every drop of fuel. The goal is bank enough memories to confort you when you're too old and nobody will take you along anymore. For good measure, always invite someone along that's older. Its good karma if you believe in such things

jddens · Post by **jddens** » Tue Dec 02, 2008 12:48 am

It's not all about going.....getting on the hook and hang'in out is about as good as it gets. Find a place close that you like and anchor out. I have a favorite spot and I can see the cover of my berth from the flybridge while anchored.........so the 20 GPH isn't such a big deal........

.......John

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Performance question F31 1971

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