Wobble

Sydwayz, How did the fuel mileage and general handling compare on those two models. I have been thinking about a 28-29' with twin sb strokers lately.

Sydwayz

iTrader: (1)

Well, there have only been 4 SBC 28ATs built. Chris Spillman claims awesome mileage with his twin 350s. You can get a hold of him here:
http://www.offshoreonly.com/forums/member.php?u=48412

Mileage though is all relative to how one drives; especially on the single. Mileage at 3000 vs. 4200 will vary greatly; as everyone has a different cruise RPM.

'Boatfreak' here on OSO can give you some input on his former 28 with a 496HO. http://www.offshoreonly.com/forums/s...d.php?t=188394

ar15meister

I am very happy with my single 750hp/ Imco SC Pantera race boat.

Reliable, idles well and lots of room to work. We do alot of our own stuff and one engine is way easier to work on. We have had 3 guys in the bilge working at the same time to put it in perspective. My buddys twin 750hawk/3a Cig is a huge pain in the ass and we need to do friggin yoga positions to do even the simplest of things. It does get annoying.

I have changed the oil once and I run Joe Gibbs race oil and the Merc HP drive lube and it is expensive enough doing regular maintenence with high quiality stuff with one engine. Buying MSD ignition cables, spare starters, top notch plugs.....it never ends (I am just a beginner and I am already learning there is way more cost and work than expected...I love it tho)Two engines would be too time consuming and costly(for me at least)

I have already seen 81.6mph on GPS and we think there may be about 3-5mph more with some tinkering. Panteras run great with a single but as usual you always want more power (our dinner table conversations have been about the 'next motor' even though I have owned the boat less than 2 months and have less than 70hrs on motor between me and the previous owner).

ECeptor

Nobody has mentioned drive cost/life

To get a big single to go fast you need big power - as in +450hp. For serious performance you are talking HP525's or more powerful. The standard Bravo is not reliable behind that power, the XR is ok depending on power and the driver. Move up to 600hp and above and you might be into more expensive drives/gear/shafts to maintain durablity.

But standard Bravo's should live forever behind a SBC - even a 400hp 383. The torque is what kills the drives, and it will likely be significantly lower on the twins.

jmeng

I know where you're coming from, was debating the same things last year. I've got a 29 Outlaw with twin 496 mags. Have several buddies with 25 Outlaws and single 496 HOs. Best I can tell I burn about 50% more gas than they do. Maintenance is going to be double. Twice as much oil, filters, outdrive fluid, etc.

Chris288

05 288 Sunsation, single 496HO, 70-72mph, ~ 2.5 mph crusing @ ~ 3,500, ~ 1-1.5mpg WOT

littledcsrodshop

iTrader: (1)

As many on here know I wrestled back & forth with the question my self & I made the decision to go with a big single over twin sbc's in a True 28' conventional bottom V.. There were many factors that came into play in making my decision & one of the main factors was $$..

As for your question of which one will cost less to maintain. Here is my 2 cents worth : It would really matter Alot on what you mean by Big single ?? & it also matters alot how the boat is maintained ?? & also who is maintaining the boat , meaning do you do all your maintnance or do you have to hire it out ?? In my opinion one mans so called "maintnance" is another mans neglect..

If you are talking 750 hp orso single vs. Stock merc. power such as stock 365 hp mercs.. ? In my opinion the twins are Not Always but Usually going to be a bit more reliable , that is if they are stock Merc. However as already mentioned when the time comes to do any work on those twins & esp. if you do your own work you will wish that you had a single...

Keep in mind that if you are talking say 750 hp orso single that you are going to need to do more regular preventive mantnance.. Such as drive lube , more frequent oil changes , just to name a few.. Also keep in mind that if you are talking about realitivly big power that Everything becomes way more critical...

If you are talking stock merc. 525 vs. say those same stock merc. 365's , of stock merc. sbc's I would definetly have to give the edge to the single... maintnace wise... b/c you are going to get many hours of trouble free running out of either of those 2 given stock setups... If they are in Good shape.. Which is another factor... Are you talking new boat ??

I listed all of the advantages & disadvantages in My particular situation & Big single was my choice... I already had most of the stuff for my big single , & I had 2 complete realitivly stock sbc's However the Small blocks would not have stayed that way ( which was a big factor ) I had 2 complete drive set ups already , & my boat was already setup for twins. To be perfectly honest I would have been happy with either setup but like I said in my particular situation the single won the coin toss...

You will get many differant opinions here & most of them will be good ones , however the best choice will be the choice that works out best for You.. The more specific you are about your boating style , maintnance , ect...ect... the better opinions & feed back you will get....

I wish you the best in either choice you make & feel free to conact me if I can be any help. For my email address just add my screen name to @comcast.net

Stormrider

Well, i kinda did.
I recently priced these 2 engine packages.
2x 475hp 350sbc closed cooled and fully dressed w/ SM exhaust
1 x 650hp BBC ditto.
Same builder. Same price.
2 drives would cost more, but a B1 behind 475hp would last forever.

Boatnuts... not many 25s w/ twins. Your setup was special due to its age.

The point at where twins gets feasable (imo) is 27-31ft.
Once above there, you can go BBCs.

TexomaPowerboater

Obviously it will cost more, but let me break it down. This is my estimated of expenses incurred thus far on my 28 apache with twin 454's 460hp modified mercs vs the single engine 502 390hp 24 python. Both were carbed engines.

1) Gas is the same, maybe even less on the apache. I run it at 3000-4000rpm as opposed to the 4000+rpm in needed in the 24. As someone else mentioned I think the benefits of better fuel consumption over a single engine boat only lies in boats 28-32ft.

2) Oil changes.....obviously twice as much, same with having the outdrives serviced. All in all oil, and outdrives was only an extra $300 per year (annual usage about 25 hours).

3) Insurance......about $870 more per year.

4) Engine replacement. Most of these big hp engines are in the $20K range. And thats what it takes to get them moving. If I blow that one engine I'm out $20K. I've seen 496's go for $10K.....so if I blow one I'm out $10K. If you blow two.........I guess your in the same boat, which ain't so bad considering the benefits. If you had twin small blocks you could replace one for as much as it would cost to rebuild some of these big HP engines.
5) Exhaust......you got me there, they will probobly last the same amount of time as a big hp single and I'll have two to replace.

Other benefits I see over the single:
1) Its faster than most 28ft single engine boats. Smoke those single's off the line and pray they don't have the top end to catch ya
2) With twin stock power vs big single your running at less rpm's to achieve the same speed and the strain on the outdrives is cut in half over the big hp single. So the outdrives should last longer.
3) Big hp engines normally required for single engine boats in the 28-30 range have shorter rebuild times than the stock merc engines. Hell I've heard of 500EFI's going to 1000hrs on a triple application. Merc's recommended rebuild time is at around 400hrs for the 500EFI.
4) One engine to get you home
5) Manuevarability around the docks
6) Extra weight for the rough.

So basically it cost twice as much for normal maintenance, but the engines and drives are also working 1/2 as much which in the long-run should make your equipment last longer. All in all excluding insurance it only cost me $300 extra to maintenance over my old single engine boat. I did do some compression test and fixed some other little things, but that goes with any boat. Hope that helps.

boatnuts

Stormrider - All the 25's are of the same vintage and were built in the early 70's. I was told several years ago by an old timerat Magnum that more than half of the 35 boats built were twins. The rear interior liners and engine covers on the singles were different. Most that I have come accross either in person or by photo over the years have been twins. A twin conversion to single gives the best engine compartment and rear deck/engine cover/lounge cushion. With the hinged rear seat pivoted ahead, everything opens up to give space galore.