Reply
 
Thread Tools Search this Thread
 
Old 12 August 2007, 13:56   #11
Member
 
Country: UK - Wales
Town: swansea
Boat name: Too Blue
Make: BLANK
Length: 8m +
Engine: Suzuki DT225
Join Date: Mar 2004
Posts: 12,791
It is a good point about development costs - the majority of 4 stroke outboards have other applications. The new yam 350 is based on a Ford V8 car engine.

As to oil going into the water a lot depends on the oil and the ratio - remember eventually a 4 stroke's oil will also end up back in the environment - especially if someone just chucks it away.
__________________

__________________
codprawn is offline   Reply With Quote
Old 12 August 2007, 14:34   #12
Member
 
Country: USA
Town: Oakland CA
Length: 3m +
Join Date: Feb 2005
Posts: 6,653
Quote:
Originally Posted by codprawn View Post
It is a good point about development costs - the majority of 4 stroke outboards have other applications. The new yam 350 is based on a Ford V8 car engine.
I think there's been a lot more research and testing on 4-strokes, due primarily to the larger market share they enjoy.

A few years back, there was some experimenting done with a 2-stroke engine that used sumped lubricating oil and ran on pure gas. Not sure why that didn't go further than it apparently did.


Quote:
As to oil going into the water a lot depends on the oil and the ratio - remember eventually a 4 stroke's oil will also end up back in the environment - especially if someone just chucks it away.
That's sort of like saying that a wood bridge is a better alternative to steel because eventually someone will toss the steel on the side of the highway. If you assume the oil is going to be recycled (and ideally, many times), well, yes, it will still end up in the environment, but only after many, many cycles of uses. A 2-stroke engines oil gets into the environment after a single use.

Speaking of which, I think my oil storage bucket is full, and today would be a good day to take it to the recyclers for emptying.

jky
__________________

__________________
jyasaki is offline   Reply With Quote
Old 12 August 2007, 14:39   #13
Member
 
Country: UK - Wales
Town: swansea
Boat name: Too Blue
Make: BLANK
Length: 8m +
Engine: Suzuki DT225
Join Date: Mar 2004
Posts: 12,791
What if it's castor oil??? Great in 2 strokes!!!
__________________
codprawn is offline   Reply With Quote
Old 12 August 2007, 14:58   #14
Member
 
Country: UK - N Ireland
Boat name: Muzungu
Make: Red Bay 650
Length: 6m +
Engine: Suzuki 200hp
Join Date: Jul 2007
Posts: 37
I think the fuel consumption of new engines, 4 and 2 stroke are the same. Oil not that important as they both use it in different ways. But power to weight is important with a small RIB. If you are using your RIB in rough water I think the 2 stroke power band has the edge. If I was buying a small Rib it would have a 2 stroke on the back and a very big RIB inboard deisel.
__________________
Bulligmore is offline   Reply With Quote
Old 12 August 2007, 15:41   #15
Member
 
Country: UK - England
Town: Essex
Boat name: Crooked Bow
Make: Zodiac Pro Open 550
Length: 5m +
Engine: Evinrude etec 115
Join Date: Jan 2007
Posts: 36
Just got back from a dive trip to the south coast during which I had a very interesting conversation with the owner of the dive centre. Basically he was very unhappy after replacing his old optimax with a V-6 Yamaha 4-stroke of comparable power (225 HP). To his surprise the latter could no longer get the rib onto the plane with a full load of divers which is basically a disaster if trying to run a diving rib service.
The latest DI technology has taken 2-strokes to the next level. They still have huge amounts of torque to draw upon whilst achieving better economy and improved emissions relative to the old 2-stroke technology. I think the Evinrude Etec has now been granted permission to operate on the Swiss lakes and is the first such 2-stroke technology to achieve this landmark. Basically the Etec is as good as a 4-stroke re. fuel economy, noise, emissions whilst having much more torque!!! The questions is why pay more for a 4-stroke that is less powerful (torque), heavier and needs servicing very 100 hours?

Dave
__________________
Dave; Essex
Daveboy 71 is offline   Reply With Quote
Old 12 August 2007, 16:45   #16
Member
 
Country: UK - England
Boat name: SOLD
Length: under 3m
Join Date: Jun 2004
Posts: 794
I think there is a pattern emerging, The Etec/ 2 stroke folk love there Etec the Four stroke people love there 4 strokes.
We all have tales to tell about the fantastic virtues of our particular engines
If the man with the dive rib changed his prop to suite the weight he is carrying it might help.On Saturday i spoke with a man who only supplies Etec,s he has had lots of problems, but then so have Yamaha with there 300 HPDI so where dose this leave us, Seams that most of the Boating done is in shore ,short bursts of power for a few miles so its not really relevant. Looking at our cruise on tues / Weds we average 38 knts to Guernsey but this worked out at about 3 to 4 miles per gallon, WOW thats some carbon foot print,some thing i have wanted to ask about is exhaust emission's into the water on cars we have catalyst converter Boat engines ?
__________________
Roy Smith is offline   Reply With Quote
Old 12 August 2007, 16:52   #17
Member
 
Country: UK - Wales
Town: swansea
Boat name: Too Blue
Make: BLANK
Length: 8m +
Engine: Suzuki DT225
Join Date: Mar 2004
Posts: 12,791
Water filtration is incredible - they are now looking at squirting it into lorry exhaust pipes.

The sea is a very big place and a little extra HNO3 will soon break down. The CO2 from the exhaust will also be absobed to a certain extent although not sure how much.
__________________
codprawn is offline   Reply With Quote
Old 12 August 2007, 17:34   #18
Member
 
Bigmuz7's Avatar
 
Country: UK - Scotland
Town: Glasgow
Boat name: stramash
Make: Tornado
Length: 5m +
Engine: Etec 90
Join Date: Feb 2006
Posts: 5,068
Quote:
Originally Posted by Roy Smith View Post
I think there is a pattern emerging, The Etec/ 2 stroke folk love there Etec the Four stroke people love there 4 strokes.
Not quite.. I think optimax is making some headway in this thread.. and thats from a fourstroke owner (me) who used to have an optimax ! Verado is good, but its heavy.. but jeez it has instant power
__________________
Bigmuz7 is offline   Reply With Quote
Old 17 August 2007, 07:09   #19
Member
 
Country: USA
Town: boston
Boat name: Miss bad 61
Make: Crapko, AKA Mako
Length: 5m +
Engine: OMC Mod50
Join Date: Apr 2006
Posts: 398
Ok then, the TWO Stroke. what is it,it IS twice the POWER at HALF THE WEIGHT
OF A FOUR Stroke.thats what it is, this was true when invented and is Still true TODAY.

ya your savin gas, goin half as fast, lugin twice the weight.
__________________
fast fred is offline   Reply With Quote
Old 17 August 2007, 09:33   #20
Member
 
Country: UK - England
Town: poole
Make: ring
Length: 5m +
Engine: 150xr2
Join Date: Mar 2006
Posts: 180
I to tend to think a bit like fast fred it's a no brainer 2stroke for me all the way, my problem is some friends are technicians for expensive well known car makes all day long they spend time fixing ever more complex problems, do you realy want to hang this kind of problem on your boat, although as somebody pointed out...who cares it will be new under warranty and when it gets a few miles under it's belt I will get shot off it...maybe but at that point to me it's worth peanuts for it's now just one complex 4 stroke with a worn cam belt waiting to let you down or worse go bang
__________________

__________________
ribit is offline   Reply With Quote
Reply

Thread Tools Search this Thread
Search this Thread:

Advanced Search

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





Copyright 2002- Social Knowledge, LLC All Rights Reserved.

All times are GMT -5. The time now is 00:39.


Powered by vBulletin® Version 3.8.8 Beta 1
Copyright ©2000 - 2017, vBulletin Solutions, Inc.