single or twins

[jimslade]

28 ft magnum single big block or twin small blocks?
dont want twin big blocks, gas is $3.75 a gallon in canada now dont need the extra expence

[LHC30Victory]

For a 28 foot lake boat, I would stay with a single as long as the boat itself is no too heavy. If it is, or ya do ocean trips, go with the twins.

[spectras only]

Twins . Met a guy with a 27 Magnum with single BBC .It was a slug getting out of the hole. I have two 6.2's in a 257 [ 24' boat ] and it's great on fuel and has incredible acceleration .What part of canada you from ? Magnums have 27 degree deadrise if I'm not mistaken and they dig a big hole. Magnuman on the board has one with twin sbc.
Send him a PM. You've said 28 , what would be a 70's hull and heavy .

[ECeptor]

I got to drive a 288 Sunsation last summer with a single HP500 and it was a rocket out of the hole and was very quick getting to it's +70mph top end.
For me, if I would be trailering the boat very much it would be a single for sure. If fuel cost was an issue, again the single wins for being lighter.
If I were going offshore or on big water, then twins would win!

[jimslade]

It was built in 1988, Don A and Jim W design. It looks like a 24 degree deadrise rear. It was built by a company in Canada for Magnum marine. only 10 or so ever got finished. I bought it 2 years ago still sitting in the finishing mould It needs stringers and the console needs to be glassed in. balsa deck.Im doing lightweight stringers,foam core.Will weight about 3200LBS without engines. paid $3000.00 canadian for it. will be very nice when finished. Bought a 1999 502 mpi for it. not sure if I want to put it in or twins. some riding will be on lake Ontario. Big lake. but mostly on smaller lakes.
Thanks for input

[Boostable]

So what would be a good weight to start thinking about twins? 5k? 6?
Still doing my research!!!
Thanks,
JW

[97SunsetterLX]

Twins burn 1.5X the amount of fuel compared to a single
Twins will last longer than single
Twins are more maneuverable in docking etc
Twins are double the maintenance cost and typically harder to work on because of limited access
Twins give you the security of being able to get home under your own power when you have a breakdown.
I had twins for 10 years – loved it
Next V hull boat I get will be a single –based on cost of maintenance, the lighter weight and the availability of pretty impressive power and reliability in a single engine configuration.

[LHC30Victory]

Twins burn 1.5X the amount of fuel compared to a single
NOT TRUE! Since you have two screws in the water, for the same speed you are running EACH motor at a lower RPM than a comparable single. i.e. my 30 runs at 3200 RPM at 52MPH (yes, GPS), where a single would probably be running at about 38-4K. So the fuel used will be less and the motors will not be working as hard as a single = or the drives :boxed:

[ECeptor]

NOT TRUE! Since you have two screws in the water, for the same speed you are running EACH motor at a lower RPM than a comparable single. i.e. my 30 runs at 3200 RPM at 52MPH (yes, GPS), where a single would probably be running at about 38-4K. So the fuel used will be less and the motors will not be working as hard as a single = or the drives :boxed:
All things being equal twins have to burn more because the boat would have to weigh more. Picture two 28'ers with identical hulls, one with twins, one with a single. Even 2 small blocks vs 1 big block the twins would outweigh the single by at least 1000lbs. That extra weight = drag = more fuel. Total power consumed to push the boat forward is substantially higher with twins. Also, don't forget to add the extra drag of the second outdrive.
You are correct that engines a more efficient by producing the same power at a lower rpm - but that's not a drastic effect. For sure it is minor enough to be over shadowed by the increased drag due to weight and a second outdrive.

[FASTERDAMITT]

I guess if your taliking twin and single of same HP, then yes a twin will most likely spin less rpm. However, My single would be several hundred HP more than one of my twins. So the rpm of the single will probably be less than the twins.

[Boat211]

One big single with Imcos "gear splitter" . Stability of twins, drives will last longer, and less weight. There is a article about it in the new ***boat. Pretty interesting.

[jimslade]

Thanks for all the info. I think Im going with twins. I dont want to be stuck offshore on the big lakes Im running on
Thanks again

[LHC30Victory]

One big single with Imcos "gear splitter" . Stability of twins, drives will last longer, and less weight. There is a article about it in the new ***boat. Pretty interesting.
That caught my eye at the LA boat show. Would go for it in a second only if ya could reverse one at a time like real twins. Maybe in its next incarnation :D

[97SunsetterLX]

Which motors are you going to use???

[ECeptor]

That caught my eye at the LA boat show. Would go for it in a second only if ya could reverse one at a time like real twins. Maybe in its next incarnation :D
Why couldn't you have one in fwd and one in rev? Assuming Bravo drives all the shifting is in the drive, right? The drive hook to the splitter box just like they would a flywheel, right?

[LHC30Victory]

Why couldn't you have one in fwd and one in rev? Assuming Bravo drives all the shifting is in the drive, right? The drive hook to the splitter box just like they would a flywheel, right?
Maybe your right, That would make sense.
Except, that you don't have the luxury of altering each screws speed! that has been important on more than one occassion :)

[ECeptor]

Maybe your right, That would make sense.
Can you teach my gf how to say that? :)
But you would not be able to independantly trottle the two, unlike a twin.

[jimslade]

I'm going with 2 efi 300 hp small blocks. I'm still not sure if I'll use alphas or bravos. I'm told that the alphas use less hp and less drag. Thanks for the Input

[FASTERDAMITT]

Sounds like a good compromise. Maybe ProChargers for Christmas! :D

[FREIND OF AA AND TA]

cant imagine not having twins. No more tows, easy steering, service sucks but oh well!

[Quality Time]

All of the smaller Magnums and Cigs I have seen run twins. I would not put anything less than that. There are factor to consider than top speed such as balance and how she will fly in the snot. Check the other sites like OSO, quite a few people have boats similar to yours and can give you first hand experience.
Best of Luck.

[u4ea32]

Single.
The Boat US tow boats are ALL single engine, and they come out to rescue the broken down boats.
Speed and fuel efficiency are closely linked by weight: the less weight the faster you go, and the less fuel you burn. A twin, unless absolutely wide open, has no performance advantage. But at all speeds, including wide open, it is far less efficient. 1500 lbs for the engine and drive etc, and then add in the extra fuel weight, and you are really dragging a lot of junk. All that junk sucks gas, and slows you down.
Also, if the engines are not running at exactly the same speed, one is pushing, the other is dragging.
I really wish my boat had a single engine instead of twin big blocks.

[JJONES]

Bought A Boat Once,27 Foot Scarab With A Single,Went Out For The First Time And Spun A Rod Bearing,This Was In The Pacific About 5 Miles Out,Almost Didnt Get Back,Once I Fixed It,I Sold It--Never Do That Again,ALOST BECAME A MEXICAN WITH THE CURRENT.Now I Own A 38 With BBC Blown X2,Yes Its More Money But Its A Great Feeling To Know Im Getting Back!Never Been Passed By A Single!Boating Like All Other Pleasures Costs Money,You Just Have To Deal With It Or QUIT EVERYTHING, Stay At Home And Wish You Were Floating!!Good Luck!! :D