Twin Etec 115's for a 23'?

[bigpine33]

Does anyone have twin Etec 115's on a 23'? I'm thinking that is the route I would like to go and I'm curious about performance and fuel economy.

I currently have twin 1994 140hp Johnsons on the back of my 23' Savage. I bought them new 16 years ago and have been very happy with them. I run 14.5x19 props and I can plane on a single engine and cruise 18 knots with the boat fairly loaded (no trim tabs). A number of times over the years, I have left the dock with only one engine running, the mission continued!

So, I have this theory that twin engines may be less expensive that a single engine in the long run. Reason being, you are not as inclined to get rid of it due to reliability concerns. When I priced two 115 Etecs vs. a 225 Etec, they are real close in price with the 115s being less than $2k more rigged/instrumented.

I'm curious if I could plane on one Etec 115? Being 2 stroke engines and comparing them with my old 140hp loopers, I think there is a chance.

I currently get about 1.1 mpg running them at 3800-4000 rpm. How much would I expect that to improve? Would it be more or less than 3 mpg?

Any thoughts or comparisons with similar setups would be appreciated.

[Bushwacker]

Skip & Carla are planning to go that route with their 21! Their boat was owned by Johnson-Kirby, a Miami dealer for the Homelite 4-stroke outboard motors in the 60's. Check out No. 26 on the home page of Carla's web site! Johnson-Kirby ran it in the offshore powerboat races with twin 55 hp Homelite/Bearcat motors! Carla may be able to confirm, but as far as I know, they won their class, since I think they were the only guys running 4-stroke outboards!

Although the 21 is a little lighter than the 23 (check the specs on Moesly SeaCraft site), it's the worlds BIGGEST 21 footer! If they could race a 21 with 110 hp with all the fuel they carried (300 gallons?), I would think you would have no problem with 230 hp if you didn't load it down too much. In fact I believe Fr. Frank has said he's rigged 23's new with twin 115's and maybe even twin 85's! However you might need a special prop to plane on 1 engine, something like a 13 3/4 x 15p. What sort of revs do you turn with the 19" prop? I'd think it would be lugging the motor down pretty bad, especially if trying to plane on one engine.

[geesea]

lets see some pictures of your savage

[65Bowrider]

I normally don't post in this section as I'm not a geek on this stuff, but ...
#26 did win her class (we don't have to mention it was the only one in her class)
More impressive was the twin 55's performed very well on the 21 in offshore conditions.
A single Etec 115hp pushes our 19' bowrider 38mph with normal load.
We plan twin 115hp for our 21, #26. Advantages, like you said, a back up engine ... also mounting apart on transom will give less draft and better stability. Not yet proven, but like Bushwacker stated, a different prop and should plane the 21' on one engine.
We are pleased with our 3 yr old Etec.

[castalot]

I like your idea but I don't think 115 would be enough 130 maybe I have twin 130 loopers never tried to go on one but I have limped home on one with bad gas a couple times one of them wouldnt run on the crap that came with the boat but the other did what would be the cost and weight difference with the 130's but the new etecs are strong so who knows!!

[bigpine33]

Thanks for the information. Yes, the 130's may be the right motors. They are only 15lbs more than the 115's, I'm not sure about the cost difference.

I turn 6000rpm WOT with my 19" props. Years ago, a buddy of mine that worked at OMC brought me some 4 bladed 15x21 props to try out and they were incredible. I got the same performance as my 19" props at 10% less RPMs. I could get up on 1 engine too. I beleive 10% less RPM translates into 10% less fuel. That would have pushed me to a whopping 1.2 MPG instead of 1.1 MPG. The props were pretty expensive but would be a great consideration.

I did find this Twin 115 Etec performance paper:
Etec twin performace stats


It is a bigger aluminum hull, I'm not sure how that translates to a seacraft hull but 3.1 MPG sounds good.

Here is a picture:



Another:

[Bushwacker]

Those sound like some pretty good props you're running! What brand/model are they? I'm running a 15x15 PowerTech that seems to work pretty well, but I'm always looking for something better!

FYI - your link to the BRP site has an extra http// in the address; it works if you remove that. That aluminum boat might be similar weight but it has a little more beam than your 23, so that would make it plane a little easier if all other variables were the same. Deadrise is the big variable that I wasn't able to find any info on.

One neat feature of the E-Tec's is the incredible mileage they get (better than any 4-stroke) when running at hull speed, where they're in the lean burn mode. If you ever run short of fuel and are worried about range, all you have to do is slow down to hull speed to get a huge increase in range! That's a significant safety factor if you ever get caught out in really rough conditions where you have to drop off plane! I know that's hard to imagine in a SeaCraft, but every boat has it's limits!

[Islandtrader]

This is just my own opinion.

Why do you need twins?

Double the money double the service double the trouble.

I know every one says safety factor...but do you know that people who cruise around the world in 40 foot blue water boats only have one engine.

Normally twins or triples are for boats that need horsepower that they can't get out of a single.

I would say in the "old" days when out boards weren't that reliable the twin thing had a safety factor, now a days I think that argument is nil.

This just my take on the whole thing.

[bigpine33]

I did think a lot about single vs. twin. Should I get 230hp in 2 motors or 225hp in one motor? And I think I want 2, here are some reasons I want to consider twins:

1) Initial purchasing cost is not that much more in the specific Etec case (not sure of other makes).

2) I've had my 1994 twins for 16 years. I think I would have replaced a single engine by now. So I am really getting my moneys worth. I've swapped parts from one to the other to troubleshoot over the years, this helps with maintenance costs and I'm deferring my initial costs so in my opinion there is some savings here.

3) This is a personal one but I use the boat exclusively in the Florida Keys where it is shallow. A single engine would reduce my draft by probably more that 6" because it would be in the middle of the V compared to twins hanging up off the bottom of the V.

4) Maneuverability in marinas and canal systems with twins is much easier.

5) Counter-rotating improves the ride in rough water because the single prop will walk the transom slightly to a side as the hull comes out of the water.

The cons I see in the twins are the higher maintenance costs and the extra weight.

I'm not sure the fuel for 1 motor is more than 2 motors? In the performance reports I read on the Etecs both are real close to 3 mpg (twin 115's vs. a single 225). You have 8 smaller cylinders being fed fuel compared to 6 larger cylinders... More drag with 2 engines... this is a hard one.

This is what makes this a great forum, and I appreciate all the input!!!

About my prop make, I got them from the OMC dealer when my engines were bought and I think they are Vipers circa 1994. The dealer had put 15X21's on to start with but I could not plane on 1. It was a luxury to try the props until I liked specific ones.

[DonV]

but I use the boat exclusively in the Florida Keys

Yes sir, I liked the picture of your boat with the old RR bridge/Overseas Highway in the background.