27 Flybridge conversion from I/O to Outboard

[3rdday]

Hi Everoyne,
I wanted to solicit technically based opinions; I know i'm about to get my ass kicked for thinking of putting a single on a heavy 27' boat.
I have sold the outdrive on my Moesly 27 Flybridge Seamaster, and I believe Im going to get the $ I want for the Bravo 454. I have already purchased a Bracket 30" setback that will fit nicely.
I plan to repower with a single new 300 E-tec, I came about this decision based on these facts and theories;

I am doing this for economy not high speed - thus 1 engine- I DO NOT PLAN ON SELLING, EVER. The EXTRA 12K for twins buys allot of fuel.
My old set up was supposedly 310 Hp at the prop
Bracketed set ups are supposedly 10-15 % more efficient
The boat will weigh about 800 (15%) Lbs Less
Etec has good fuel economy and can NOW tell you best throttle position on the fly.
I am not concerned with reliability, it will be a new motor, and I have Seatow, two VHF, Cell Phone, and EPIRB, and overkill on safety flotation devices.
Two strokes provide power on every stroke, versus everyother on 4 strokes.
The Seacraft Bottom itself is more efficient than other hull bottoms.
I have seen other 28' with single Etec perform well , not quite as heavy but close.

What do you all think?

[shine]

If you plan to keep it for a long time, I think that set up might be hard to sell to others. It might look a little funky.

No technical reason to not do it, just have to get the weights right.

BUt if the plan is to keep it for many year, run it a lot, then I would pay the extra now if for only the pleasure of having no noise at idle.

I think if you figure a couple hundred hours of use per year (with one motor you will probably run it all the time while your out), the efficiency of a 4strk at idle is huge over a 2stk.

The FWC guy who came to inspect my boat damage last night said he picked up a 300 Suzuki rigged for under $17k from a dealer down south, I think he said it was in Pompano

[gofastsandman]

E tecs are much more efficient at low rpm than 4 strokes. Carb`d smokers? Yeah, they suck fuel at low rpms. Lots.

E tecs are DI.

Brian, a Mike Wilson recently came by our shop. His SUV had a 7 marine sticker on the rear window. He said Monty Racing was making E tecs outta old V8 300 Rude blocks. Said they take 2 fuel rails from the v6 motahs, cut and weld them for v8`s and are making north of 500 @ the prop.

Mike said Yamaha has offered Gordon boat loads of cash for his technology. Monty racing is the go to shop for Rude racers. He can build for longevity as well.

http://www.montyracing.com/index.html

I think you may be a little heavy for a single 300. Send your queery a little south maybe.

The old 21 ran with Homelite 4 strokes. 55 Bearcats. Based off of the Crosley modular design.

You may be suprized by that torque. Mr. Denny`s 150 jumps out of the hole. And I do mean hang on.

Cheers,
Us chickens

[3rdday]

Thanks Joel you rig is looking nice!!

I would gain 300lbs over 2 stroke with a 4 stroke

I can get a 300 etec for 19k

Sandy
I was considering one of the old 300 v8 4.0. They hold the speed record for single OB.
They are fuel pigs. There was a stock motor tuned on the dyno @375hp.

I was already aware of Monty and their history with the ole v8s.



I'm glad to learn the 300 etec can be pushed for more power
You answered a question I never posed, I wondered if the etec 300 could be modified for more POWER.

[3rdday]

7 marine I am fa,Iliad with it a friend of mine who used to work at lake x and one of the foremost racing outdrive experts had a hand in the drive unit. He does drives that handle 1200+ hp

[McGillicuddy]

Brian,
I like to fish cheap for as long as I can, so I like the idea (sorry I'm getting so technical here...)

I've never seen a performance bulletin on the 27 so i really don't have a clue as to the weight involved. I don't recall a rebuild thread on your 27 so not sure if you cut some weight with current composites. I think the 300 e-tec could get you near 35 mph with a big ole SeaCraft friendly 15p prop and it will likely double your economy at cruise over the 454/Bravo and untold gains in the manatee zones

Etec DIs at idle and low speed troll kick a$$ on efficiency so I'm not sure I'll bite on the 4s vs 2s argument any more. Nominal at best with modern DI at play.

Less weight, less drag, cleaner water for prop = better perf.
Might consider a big bracket on that will accommodate twins in case you are unsatisfied with performance, but overall, I like the idea.

Side note - what did you repower the 21 with?

[Bushwacker]

Brian,

Here's a thread on the E-Tec Owners forum you might want to check out. http://www.etecownersgroup.com/post/...03692?trail=15 This owner had a 300 on a big 30' aluminum boat, and he's a mechanical engineer, so you might join the forum and send him a PM. I'm sure he know the weight of that rig and how much load he was carrying. You might want to pose the same questions to that Forum also, as it's excellent, similar to CSC in the wealth of knowledge there and friendly folks willing to help any way they can.

Skip and DonV said the Sea Mistress had PLENTY of power with the twin 250 HPDI's on a bracket, even though Carl said they were mounted way too close together, as most twins are on the SeaCraft hulls. He always mounted the twins in the center of the center panels on his race boats to get them in the cleanest water. You won't be nearly as fast with a single 300, but you'll only be feeding about half as many cubic inches as that 454, so I'd think fuel economy would be fairly decent, especially when you lose that much weight!

What sort of bracket did you get? You might want to consider a jack plate, because I don't think you'll have to worry about stern weight, but getting the engine height correct will make a big difference in performance. The AV plate wants to be out of the water. I'm still at least an inch too low even after Don redrilled the motor mounting holes to raise them an inch, with bolts in the bottom holes on motor bracket. Denny

[DonV]

Naw on the Etec, you gotta get one of these 557 hp monsters. seven-marine.com

Heck any "outboard" with a transmission NOT in the lower unit and can swing an 18" prop is what ya have to have for the 27. Shoot, I'm thinking way into the 50 mph range with one of these. Don't worry about the initial cost, it's only money. 2012 technology on a 1967 SeaCraft....that's cool.

[gofastsandman]

Originally Posted by 3rdday

Thanks Joel you rig is looking nice!!

I would gain 300lbs over 2 stroke with a 4 stroke

I can get a 300 etec for 19k

Sandy
I was considering one of the old 300 v8 4.0. They hold the speed record for single OB.
They are fuel pigs. There was a stock motor tuned on the dyno @375hp.

I was already aware of Monty and their history with the ole v8s.



I'm glad to learn the 300 etec can be pushed for more power
You answered a question I never posed, I wondered if the etec 300 could be modified for more POWER.

Brian,
I don`t know what Monty is doing with the E tecs.

They are making the old V8 carb motors into DI "Etecs" which produce the big numbers.

[3rdday]

Way Cool Denny thanks for the G2.
The Thought Had crossed my mind,I had already been shopping for Jack Plates.
I have A large Dusky Bracket with big flotation, Guess What???? It fits in the pocket on the transom perfectly and at the anticipated correct height!!!!!!I got the bracket for $200
Looking for hydraulic steering now, and the DI old V8 Evinrudes I am intrigued...

BTW Everyone that 7Marine 575 hp engine is 70-80k

AND- DID YOU SEE THE TURBO DIESEL OUTBOARD?????

Originally Posted by Bushwacker

Brian,

Here's a thread on the E-Tec Owners forum you might want to check out. http://www.etecownersgroup.com/post/...03692?trail=15 This owner had a 300 on a big 30' aluminum boat, and he's a mechanical engineer, so you might join the forum and send him a PM. I'm sure he know the weight of that rig and how much load he was carrying. You might want to pose the same questions to that Forum also, as it's excellent, similar to CSC in the wealth of knowledge there and friendly folks willing to help any way they can.

Skip and DonV said the Sea Mistress had PLENTY of power with the twin 250 HPDI's on a bracket, even though Carl said they were mounted way too close together, as most twins are on the SeaCraft hulls. He always mounted the twins in the center of the center panels on his race boats to get them in the cleanest water. You won't be nearly as fast with a single 300, but you'll only be feeding about half as many cubic inches as that 454, so I'd think fuel economy would be fairly decent, especially when you lose that much weight!

What sort of bracket did you get? You might want to consider a jack plate, because I don't think you'll have to worry about stern weight, but getting the engine height correct will make a big difference in performance. The AV plate wants to be out of the water. I'm still at least an inch too low even after Don redrilled the motor mounting holes to raise them an inch, with bolts in the bottom holes on motor bracket. Denny