|
|
24-11-2005, 11:06 PM
|
#21
|
numbskull
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
|
I think, like it says somewhere in that S & F thread, the amout of load the flywheel puts on the motor is nowt compared to that of the prop, and probably such a small force in the scheme of things that it's virtualy imeasurable.
load on the top bearing generally, and the gyroscopic loads, mean it has to be better to be light, and as you've already said, reduced rotating mass must help with transmission life when there's enough 'chop' to have the motor regulary 'barking', under full power.
__________________
__________________
.
"I Agree with everything you say really!" - John Cooke to Jon Fuller - 26-01-2013
|
|
|
24-11-2005, 11:53 PM
|
#22
|
Registered User
Country: USA
Location: Florida
Boat make: 1996 STV Euro
Engines: 2.5L 260 ROS
Join Date: Dec 2004
Location: Florida
Posts: 58
|
lightenend wheel accelerates slightly faster, nothing on the top end. Easier on the bearings, especially over 7500 rpms. No disrespect to Jay, he is an outboard guru and a great guy, but he also sells some of the nicest lightened flywheels on the market... probably going to get a glowing report from him about their benefit.
There is also some speculation about the lightened being not quite as fast top end due to the inertial effect of the slightly heavier wheel spinning... I am not smart enough to know the difference but just thought I would throw it out there as long as everyone is on the subject.
fish
PS they look cool.
__________________
|
|
|
25-11-2005, 03:21 AM
|
#23
|
Large member
Country: England
Location: On the farm
Occupation: General Trouble Causer Salterns Boatyard
Interests: Official smartass
Boat name: Seahorse.org
Boat make: a V24 and a SLOW unstable ICE Bladerunner
Engines: 2x300 promax, 320 Volvo
Cruising area: England/France & Med
Join Date: May 2005
Location: On the farm
Posts: 2,681
|
So what would you recon would be the efect? in % increase? Worth the money spent?
|
|
|
25-11-2005, 03:23 AM
|
#24
|
Registered User
Join Date: Mar 2004
Posts: 6,891
|
%increase in speed likely to be 0
%increase in coolness - massive
|
|
|
25-11-2005, 03:28 AM
|
#25
|
Registered User
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 verytricky
So what would you recon would be the efect? in % increase? Worth the money spent?
|
if you are drag racing and need every tenth of a second, then it is probably worth it. If you are turning your motor over 7500 rpms for any length of time, then it is probably a good idea to save wear and tear on the bearings. If you are making a really cool looking motor and have lots of cash, then it makes for good bling bling. Otherwise, IMHO, the stock hi-po flywhell is ok the way it is.
|
|
|
25-11-2005, 03:47 AM
|
#26
|
Large member
Country: England
Location: On the farm
Occupation: General Trouble Causer Salterns Boatyard
Interests: Official smartass
Boat name: Seahorse.org
Boat make: a V24 and a SLOW unstable ICE Bladerunner
Engines: 2x300 promax, 320 Volvo
Cruising area: England/France & Med
Join Date: May 2005
Location: On the farm
Posts: 2,681
|
Well at £800 a set, I think I will pass that then.
I currently rev at 5200 - promices 6400. So i wil not need the flywheel lightened...
|
|
|
25-11-2005, 08:27 AM
|
#27
|
Registered User
Country: England
Location: South West
Occupation: Development engineer
Interests: Fast boats
Boat name: Xtreme
Boat make: Bernico 21
Engines: Mercury F1, 300 Drag, XR2 "Fingerported"
Cruising area: South West
Join Date: Mar 2004
Location: South West
Posts: 1,043
|
260+Drag same Block
Quote:
Originally posted by TheMutzNuts
The 280 is a 2.5l engine, as is the 260 and 300 drag.
The 280 makes 280hp, 260 makes 260hp and the 300 drag makes over 300hp
These are all 2.5 ltr engines, the 260+drag have the same/similar block but the 280 block is completely different .
|
JBD two reply's from you and not one comment about this!!!!
Your slipping!
The 280 and the Drag are based on the same block not the 260 and the Drag.
The Drag Motor is the same block as the 280 with different port heights and slightly bigger exhaust chest.
It does however run the 260 electronics with it own ECU.
Cyco
|
|
|
25-11-2005, 01:09 PM
|
#28
|
hello
Join Date: Mar 2004
Posts: 2,739
|
Re: 260+Drag same Block
Quote:
Originally posted by Cyco
JBD two reply's from you and not one comment about this!!!!
Your slipping!
|
oh yeah, my brain was in flywheel mode
|
|
|
25-11-2005, 01:29 PM
|
#29
|
hello
Join Date: Mar 2004
Posts: 2,739
|
Quote:
Originally posted by Jon Fuller
I think, like it says somewhere in that S & F thread, the amout of load the flywheel puts on the motor is nowt compared to that of the prop, and probably such a small force in the scheme of things that it's virtualy imeasurable.
load on the top bearing generally, and the gyroscopic loads, mean it has to be better to be light, and as you've already said, reduced rotating mass must help with transmission life when there's enough 'chop' to have the motor regulary 'barking', under full power.
|
So the flywheel is there purely to make the idle smoother?
|
|
|
24-12-2005, 02:33 AM
|
#30
|
Registered User
Country: USA
Location: Annapolis, Maryland
Occupation: HVAC tech
Interests: Outboard boat racing
Boat name: Green Eggs
Boat make: Pugh 13 ft racing hydro
Engines: Mercury
Cruising area: Chesapeake Bay
Join Date: Nov 2005
Location: Annapolis, Maryland
Posts: 8
|
Smooths idle, safely carrys alternator magnets and starter ring gear .... yeah, that's it
__________________
since 1925 about 150 different models of racing outboards have been made
https://www.boatracingfacts.com/
|
|
|
24-12-2005, 04:44 AM
|
#31
|
Large member
Country: England
Location: On the farm
Occupation: General Trouble Causer Salterns Boatyard
Interests: Official smartass
Boat name: Seahorse.org
Boat make: a V24 and a SLOW unstable ICE Bladerunner
Engines: 2x300 promax, 320 Volvo
Cruising area: England/France & Med
Join Date: May 2005
Location: On the farm
Posts: 2,681
|
It supposedly provides more power in electrical terms? What is up with that?
|
|
|
26-12-2005, 09:48 PM
|
#32
|
Senior Member
Country: netherlands
Location: Mijdrecht/holland
Occupation: truck repair
Interests: fast boats/porches
Boat name: bernico cat
Boat make: bernico 26 cat 2x 2,5,s
Engines: merc,s 2,5 EFI,s
Cruising area: ijselmeer
Join Date: Dec 2005
Location: Mijdrecht/holland
Posts: 382
|
flywheel
I know this has nothing to do with a boat, but a friend of me is doing kart racing ,and he has different flywheels ,different in weight,he says : when I have a long piece in the track that ends in a long corner and its windy than I experiment with a heavier wheel,because the energy in the heavier wheel will help me sometimes to go a bit faster into the wind and helped me to make a better time.
The earlier 300 drags were based on the 260 EFI block.
Later they used the newer block with the o rings in the heads.
Mercury says the newer style electronics PCM 555 are not keep up to more than 9000 rpm,s because the ignition charge is slower than Capacitor discharge.(earlier system)
sterling
|
|
|
14-01-2006, 01:51 AM
|
#33
|
Trade Member
Country: United States
Location: South Texas. USA
Occupation: Own JSRE ( Jay Smith Racing Engines )
Interests: ACCELERATION (anykind )
Join Date: Jan 2006
Location: South Texas. USA
Posts: 244
|
The advantage of lighter flywheel on Mercury engines are two fold. Ours , ( the lightest non exotic metal one on the market ) helps the inferior Mercury upper bearings , also a flywheel flexes backward under accelleration and forward on decelleration. The top bearing on the new and old style block sucks and the first point of real containment is above the first middle main bearing and above that is were EVERY Mercury crank breaks. You want to lessen the rotating mass to prevent the heavier stock flywheel from flexing MORE and also reduce weight to help acceleration , I cut a Mercury High Performance aluminum flywheel from 7.9 lbs to 4.9 for F1 and Drag racing and turn them 11, 300 rpms with no problems!
Cheers ,
Jay @ JSRE
__________________
|
|
|
|
|
Thread Tools |
|
Display Modes |
Linear Mode
|
Posting Rules
|
You may not post new threads
You may not post replies
You may not post attachments
You may not edit your posts
HTML code is Off
|
|
|
|
» Recent Threads |
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|