Texasmark
Supreme Mariner
- Joined
- Dec 20, 2005
- Messages
- 14,795
The first good cold front hit N. Texas today and you can't farm in the rain. Cows are fed and all the equipment is "temporarily" fixed, so nothing to do in the shop.
So back to the house, get on the puter and talk about boats.
Today I happened to be on the Boston Whaler web site and looked over their 17' to 19' offerings. On their site they had some graphical (I love graphs, used to do them as often as I could at work) data on performance of a couple of their different boats with different engines.
In short, what all the "good ole boys" (won't name favorites but there are a couple of dozen of you out there.....you know who you are, as I do) told you was right there on the charts.
Best efficiency (and smoothest ride for you old folks...grin...self included) was just over planing speed....when the boat came out of the hole and the bow dropped down ....so that you could see over it, and the boat started picking up speed on it's own.
WOT speeds varied as did the hulls and engines and that's not important.
What is important is that the 10% rule (fuel consumption in gph at WOT is about 10% of your engine hp) held for a 115 four cycle Merc and a 225 Optimax 2 cycle Merc......so you get no lift by going to 4 stroke when compared to the efficiency of 2 strokes with today's technology.......so if you want to spring for a 4 stroke you need another reason to justify the parts count, weight, and $$$.
Other thing was that when you get "just on plane" at 3250 rpm's give or take, you are running about 1/3 your WOT fuel consumption regardless of 2 or 4 stroke. The 225 ran right at twice as much as the 115 even with the different technology.
So, boys and girls, I'm convinced, a convinced skeptic.
Now all I need to do is figure out how to talk the wife into a new rig........grin
Mark
So back to the house, get on the puter and talk about boats.
Today I happened to be on the Boston Whaler web site and looked over their 17' to 19' offerings. On their site they had some graphical (I love graphs, used to do them as often as I could at work) data on performance of a couple of their different boats with different engines.
In short, what all the "good ole boys" (won't name favorites but there are a couple of dozen of you out there.....you know who you are, as I do) told you was right there on the charts.
Best efficiency (and smoothest ride for you old folks...grin...self included) was just over planing speed....when the boat came out of the hole and the bow dropped down ....so that you could see over it, and the boat started picking up speed on it's own.
WOT speeds varied as did the hulls and engines and that's not important.
What is important is that the 10% rule (fuel consumption in gph at WOT is about 10% of your engine hp) held for a 115 four cycle Merc and a 225 Optimax 2 cycle Merc......so you get no lift by going to 4 stroke when compared to the efficiency of 2 strokes with today's technology.......so if you want to spring for a 4 stroke you need another reason to justify the parts count, weight, and $$$.
Other thing was that when you get "just on plane" at 3250 rpm's give or take, you are running about 1/3 your WOT fuel consumption regardless of 2 or 4 stroke. The 225 ran right at twice as much as the 115 even with the different technology.
So, boys and girls, I'm convinced, a convinced skeptic.
Now all I need to do is figure out how to talk the wife into a new rig........grin
Mark
