proformance and the wallet

Lucky Penny

Petty Officer 3rd Class
Joined
May 3, 2003
Messages
82
I know there have been many threads and replies concerning proformance and various methods to improve it. Well here is the other side of the coin. With fuel cost as they are, and increasing, it is no longer a matter of how fast one can get from point 'A' to point 'B', but rather if he/she can afford to cast off.

Now for my question. Are there any tuning tips, prop issues, etc to improve the low to mid range proformance of a boat. for a target say <2800 RPM

right now I am running a Merc 350 CID (5.7L) 250HP pushing an approx 5000#-5200# express cruiser.

Thanks
 

Bondo

Moderator
Staff member
Joined
Apr 17, 2002
Messages
71,082
Re: proformance and the wallet

Ayuh,..........
Basically,.........

If you keep your driveline in Perfect Tune, with regular maintance, to factory spec.s,.........
That's about as Good as it gets..........

If you're Motorhead enough to start cutting back on the fuel curve,....
You'll be running the risk of an engine Melt-down............

I suppose there might be some improvements that could be made to the running surface of the Hull,.....
I think just keeping it Clean would probably benefit Most dock-boats......

So,........ I guess it depends on your interests,+ Talents...........
 

Don S

Honorary Moderator Emeritus
Joined
Aug 31, 2004
Messages
62,321
Re: proformance and the wallet

Yearly tuneups (at the beginning of the MAIN boating season in your area), and constant preventive maintenance, along with having your prop in the proper WOT rpm range (high side of the range), and using a fuel flow meter to find YOUR best mpg on YOUR boat.
The fuel flow meter will also let you know immediatly when something is wrong.
 

Flukinicehole

Petty Officer 1st Class
Joined
May 29, 2004
Messages
365
Re: proformance and the wallet

Short of changing it over to a diesel follow there advice.
 

wca_tim

Lieutenant Commander
Joined
May 28, 2007
Messages
1,708
Re: proformance and the wallet

I know I had read that prop changes can have a huge effect on performance, but I didn't appreciate just how much until really comparing of number of props on my currrent set-up. out of a half a dozen props, a couple perform in the same range in terms of top end and holshot, but there is one Turbo I have that does better on holeshot, 5-6 mph faster on top end AND has a half throttle cruise speed of about 5 mph faster than any of the others... meaning that while I haven't checked fuel economy, it probably will go significantly further than the others at around half throttle... It is a higher picth (26") than the others that perform well.

In other words, I wouldn't rule out prop changes, it's not just a simple issue of pitch, etc.. not even close
 

pine island fred

Lieutenant Junior Grade
Joined
Dec 20, 2002
Messages
1,144
Re: proformance and the wallet

Get ride of all the excessive weight you may have accumulated on the boat. Amazering how useless stuff can be accumulated on a boat that you might/maby need sometime. Especially the water tank at 8.5 lbs. per gallon. FRED
 

Lucky Penny

Petty Officer 3rd Class
Joined
May 3, 2003
Messages
82
Re: proformance and the wallet

Thanks for the input.
I try to keep her tuned to spec's. but that brings up another question. I changed over from points to electronic ign, and I have been told by a number of shade tree mech's that I should lower the timing from 8'BTDC to 4'BTDC. Any comments about that? I also know that running a smaller pitch prop reduces the work load on the engine. I know it will reduce the speed to go lower but the overall GPH should increase. Any comments.
 

Don S

Honorary Moderator Emeritus
Joined
Aug 31, 2004
Messages
62,321
Re: proformance and the wallet

Stick with the 8?.
No matter what prop you use, you must keep the engine WOT rpms in the upper limits of the manufactures WOT range for best engine performance and economy. If you have a WOT to low, you are overloading the engine, to high and you aren't using all that is there.
 

Bondo

Moderator
Staff member
Joined
Apr 17, 2002
Messages
71,082
Re: proformance and the wallet

Stick with the 8?.

Ayuh,.... Alittle off topic,......
But,......
Don, How did you do That,..??..??....
I always use *, as in 8*..........
Where'd you find that ?,..??......

Just wondering if there's a key here, that I just can't see.................:rolleyes:
 

Don S

Honorary Moderator Emeritus
Joined
Aug 31, 2004
Messages
62,321
Re: proformance and the wallet

Easy
Hold down the ALT key and using the number key pad only (won't work on the numbers over the letters on the keyboard) hit 0176 and let off the ALT key. Bingo-------- ?
 

Bondo

Moderator
Staff member
Joined
Apr 17, 2002
Messages
71,082
Re: proformance and the wallet

?....................

Ayuh,....... Way Cool,........

Thanks Don,.........

You've Made my day,....... I've learned something for today.........;) :)
 

wire2

Lieutenant Commander
Joined
Jun 25, 2007
Messages
1,584
Re: proformance and the wallet

The ? is one of many characters from an extended ascii code table. (American Standard Code for Information Interchange)

Many others at http://www.asciitable.com/ , lower table.
[ALT]xxx will print them on screen.

My 2?
 

Wotam

Petty Officer 2nd Class
Joined
Jul 22, 2007
Messages
108
Re: proformance and the wallet

I think Don's advice about the fuel flow meter is on the money... (literally). If you know fuel flow and speed you can optimize your cruising speed for best economy.

Clean bottom.
Effecient Prop.
Lighten the load.
Experiment with boat trim, trim tabs, weight distribution.
Tuned engine.

No matter what you do, with a 5200 lb express cruiser it is still gonna hurt at the pump though.
 

HT32BSX115

Supreme Mariner
Joined
Dec 8, 2005
Messages
10,083
Re: proformance and the wallet

But only on a computer with the Microsoft virus installed.

It doesn't work on my Linux computer. (probably because I'm using a different character set or something) I haven't figured out what does work yet. ALT + numbers on the main keyboard are supposed to work but it doesn't work either!

I love to be different!!

I tried it with Firefox and Konqueror (which is the same as the MAC Safari), 2 very different browsers....I probably need to change the encoding or something.







The ? is one of many characters from an extended ascii code table. (American Standard Code for Information Interchange)

Many others at http://www.asciitable.com/ , lower table.
[ALT]xxx will print them on screen.

My 2?
 
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