W I D E Open Throttle

LazyCruiser

Petty Officer 2nd Class
Joined
Jun 20, 2010
Messages
123
Hi, so I finally put my pedal to the metal on my 2452 Bayliner Classic. It's a '95 w/ a 5.0 and an Alpha one. I ran it full blast for about 20 mins. Here's my tale of the tape:

max rpm = 4400
top speed = 29 mph (gps)
this is w/a 4 blade prop, 15x15 aluminum
the boat was fairly lightly loaded - 2 ppl, 2 dogs maybe 500 lbs

Does this sound about right to you all?
Oh yea, sucked down about a gallon of fuel per minute, or so it seems :eek:

Thanks for any input!
Sarah
 

Bondo

Moderator
Staff member
Joined
Apr 17, 2002
Messages
71,103
Re: W I D E Open Throttle

max rpm = 4400
Does this sound about right to you all?
Oh yea, sucked down about a gallon of fuel per minute, or so it seems

Ayuh,..... Sounds about Right...
4400 rpms/wot is about right....
 

ChampionShip

Petty Officer 1st Class
Joined
Mar 18, 2010
Messages
202
Re: W I D E Open Throttle

Seems pretty normal to me. Those Bayliner Classics are a pretty chunky boat and takes some power to get it moving, and they aren't a racer by any means. Decent numbers for that boat.
 

Don S

Honorary Moderator Emeritus
Joined
Aug 31, 2004
Messages
62,321
Re: W I D E Open Throttle

While you are in the ballpark, 4200 to 4600 rpm at WOT is where you should be with a NORMAL load. The one thing you don't need is to see less than 4200 rpm at your normal load or even lower if the load is heavier than normal.
I am going to move this over to the prop forum, sounds like your engine is ok, but you may need some fine adjustments to the prop to get it the best you can.
 

LazyCruiser

Petty Officer 2nd Class
Joined
Jun 20, 2010
Messages
123
Re: W I D E Open Throttle

Thanks everyone

Yes it is a clunky boat and no, I won't be running it that fast very often I can't feed her enough :)

One thing that I will need to learn is how to trim up my boat

And oh, sorry for posting wrong place again :rolleyes:
 

steelespike

Supreme Mariner
Joined
Apr 26, 2002
Messages
19,069
Re: W I D E Open Throttle

basic rule of thumb gph is about 10% of the hp.
190 = 19 gph(gallons per hour)@ wot.
 

Robbabob

Senior Chief Petty Officer
Joined
Jun 5, 2009
Messages
678
Re: W I D E Open Throttle

Thanks everyone

Yes it is a clunky boat and no, I won't be running it that fast very often I can't feed her enough :)

One thing that I will need to learn is how to trim up my boat

And oh, sorry for posting wrong place again :rolleyes:

If you got your numbers when not trimming, you will see an improvement in gas consumption when you do. Also, the rpm's should increase as you "free" the boat up.

Let us know....

Happy boating!
 

dsiekman

Senior Chief Petty Officer
Joined
Jul 7, 2010
Messages
798
Re: W I D E Open Throttle

basic rule of thumb gph is about 10% of the hp.
190 = 19 gph(gallons per hour)@ wot.

Does that rule apply to twins as well? For example, twin 5.0's at 250hp each, so 50 gph at WOT? Just curious.
 

QC

Supreme Mariner
Joined
Mar 22, 2005
Messages
22,783
Re: W I D E Open Throttle

Yes ^^^^^ OBs too. However, the latest MPI engines are getting as good as 70% of that so 7 GPH per 100 horsepower at WOT. New carb stuff around 8 GPH per 100. A great place to compare that data is BoatTest.com . . .
 

Tail_Gunner

Admiral
Joined
Jan 13, 2006
Messages
6,237
Re: W I D E Open Throttle

http://www.innovatemotorsports.com/resources/marine-carb.php


Boats are not at all like cars..Both carbs and FI are in a very primitive form. In essecence it all evolves what works best for all the masses..A single big club approach.

You can however take the time to tune your boat to a much higher level of efficieny than it is currently operating at...But that is expensive


WOT..i have another article if i can find it..OK read away

http://www.proboat.com/wide-open-throttle.html

http://webcache.googleusercontent.c...rticle/31+WOT+boats&cd=20&hl=en&ct=clnk&gl=us


An engine that is under revving is lugging. This places a tremendous load on the pistons, crankshaft and bearings and can cause detonation, piston seizure and other engine damage.
 
Top