Boatmad.com


Reply
 
Thread Tools Display Modes
 
Old 02-12-2005, 05:20 PM   #1
Registered User
 
Country: uk
Location: dorset
Interests: wasting money on boats
Boat name: aquilla .
Boat make: Superhawk 40. Ring 21E. Seadoo gtx. Windy Khamsin
Engines: Kad 300s. 300xs Dbr .d6 370 230 4tec
Cruising area: corfu

Join Date: Mar 2004
Location: dorset
Posts: 570
2.5

can anyone tell me what is a 2.5efi 280 ros is, i no it's an outboard v6 merc but what do's ros stand for
__________________

Rockey is offline   Reply With Quote
Old 02-12-2005, 05:28 PM   #2
hello
 

Join Date: Mar 2004
Posts: 2,739
Race Off Shore, it has a higher revlimit (8200rpm) than the consumer model (7500rpm) and no waranty. The consumer model also had 1 years waranty, other than that they are the same. I think most of the 280's in the UK are the ROS version.
__________________

JamesM is offline   Reply With Quote
Old 02-12-2005, 05:40 PM   #3
numbskull
 
Jon Fuller's Avatar
 
Country: United Kingdom
Location: South
Occupation: none
Interests: none
Boat name: Leviathan
Boat make: Phantom 28
Cruising area: South Coast

Join Date: Mar 2004
Location: South
Posts: 15,959
So the extra 700 rpm costs you the waranty! that has to tell you summat! (about revvin a 2.5 too high)
__________________
.

"I Agree with everything you say really!" - John Cooke to Jon Fuller - 26-01-2013
Jon Fuller is offline   Reply With Quote
Old 02-12-2005, 05:46 PM   #4
hello
 

Join Date: Mar 2004
Posts: 2,739
Yup
JamesM is offline   Reply With Quote
Old 02-12-2005, 05:48 PM   #5
Registered User
 
Country: uk
Location: dorset
Interests: wasting money on boats
Boat name: aquilla .
Boat make: Superhawk 40. Ring 21E. Seadoo gtx. Windy Khamsin
Engines: Kad 300s. 300xs Dbr .d6 370 230 4tec
Cruising area: corfu

Join Date: Mar 2004
Location: dorset
Posts: 570
is there a reason for going to 8200 if there 280 bhp the standard
motor must produce the same hp, so why rev it more?
Rockey is offline   Reply With Quote
Old 02-12-2005, 05:52 PM   #6
numbskull
 
Jon Fuller's Avatar
 
Country: United Kingdom
Location: South
Occupation: none
Interests: none
Boat name: Leviathan
Boat make: Phantom 28
Cruising area: South Coast

Join Date: Mar 2004
Location: South
Posts: 15,959
.......
Attached Images
 
__________________
.

"I Agree with everything you say really!" - John Cooke to Jon Fuller - 26-01-2013
Jon Fuller is offline   Reply With Quote
Old 02-12-2005, 05:59 PM   #7
hello
 

Join Date: Mar 2004
Posts: 2,739
Not sure as the Mercury website used to claim that the ROS version produced 280hp @ 8200rpm and just said the consumer model produced 280hp. The old 260 peaked at somewhere around 7200 to 7500rpm with 260hp and the 300 Drag produced 300hp @ 9000rpm. So makes me wonder if the consumer 280 really did produce 280hp as it its mechanically the same as the 280 ROS but could only rev to 7500rpm. Who knows!!!
JamesM is offline   Reply With Quote
Old 02-12-2005, 06:13 PM   #8
Registered User
 
roofer's Avatar
 
Location: GOLDEN MILE
Boat name: LILY THE PINK AND TERMINATOR 11
Boat make: PHANTOM 21 AND 20
Engines: 2.5 EFI X 2

Join Date: Mar 2004
Location: GOLDEN MILE
Posts: 2,475
I thought consumer 280 revved to 7750 and ros to 8250.
__________________
PLEASE DON'T STEAL...THE GOVERNMENT DON'T LIKE THE COMPETITION
roofer is offline   Reply With Quote
Old 02-12-2005, 07:19 PM   #9
hello
 

Join Date: Mar 2004
Posts: 2,739
Yeah I think your right but I remember reading on the Mercury site that the power output of the ROS version was 280hp @ 82something RPM and thinking how can the consumer model make 280hp if it doesnt rev that high and why dont they say what RPM its power peaks at. All they stated for the consumer model was its maximum power output and its maximum rpm, two different specifications on different lines of the specification list.
JamesM is offline   Reply With Quote
Old 03-12-2005, 02:49 AM   #10
Registered User
 
fish's Avatar
 
Country: USA
Location: Florida
Boat make: 1996 STV Euro
Engines: 2.5L 260 ROS

Join Date: Dec 2004
Location: Florida
Posts: 58
Quote:
Originally posted by Rockey
is there a reason for going to 8200 if there 280 bhp the standard
motor must produce the same hp, so why rev it more?
Could be a couple of reasons depending on application or goal. If you wanted to turn a smaller pitch prop for greater acceleration, the additional rpms would allow decent top end numbers where the consumer motor would hit the limiter sooner. Additionally, 700 rpms when plugged into a prop calculator will yield greater top speed assuming you can turn the prop to the 8200.

Example:

32p prop, 1.87 gears, 10% slip, @ 8200rpms= 119.6 mph/192.47kph
32p prop, 1.87 gears, 10% slip, @ 7500rpms= 109.4 mph /176.06kph
fish is offline   Reply With Quote
Old 03-12-2005, 10:35 AM   #11
Traveling
 
Country: UK
Location: Alderholt
Occupation: Aerospace
Boat name: T/T D2S
Boat make: Midas 27' Cat, Argo 16 Cat. Avon Rib Thingy
Engines: Merc 280-ROS -JSRE,65Xs, 75 Stinger, Yam 60
Cruising area: Any Seedy Bar

Join Date: Sep 2004
Location: Alderholt
Posts: 4,225
Mapping is different on the power curve, the Race being all top end. Racing a motor spends most of it's time in that upper 25%.
Where a consumer goes there once in awhile, mostly living around the 75% mark but can achive the same power if required.

Consumer far more usable for non race use, plus there is a big differenced in the TBO times

EDIT: (TBO-Time Between O'hual)
__________________

__________________
It is impossible to lick your elbow.

Team25Racing.com

At least 75% of people who read this will try to lick their elbow!
BluFin is offline   Reply With Quote
Reply

« painter | P18 »
Thread Tools
Display Modes

Posting Rules
You may not post new threads
You may not post replies
You may not post attachments
You may not edit your posts

BB code is On
Smilies are On
[IMG] code is On
HTML code is Off
Trackbacks are Off
Pingbacks are Off
Refbacks are Off


Powered by vBadvanced CMPS v3.2.3

All times are GMT +1. The time now is 08:23 AM.


Powered by vBulletin® Version 3.8.8 Beta 1
Copyright ©2000 - 2024, vBulletin Solutions, Inc.
×