Single or twin engine
 

i want to buy a used 29 to 32 ft performance boat(2000 to 2003) and not sure which way to go as fa as engines ,i am sure its an old question but what is the best way to go ....single engine with big HP or twin with normal HP advantages with weight gain versus HP ,handling etc i just want to run low 70 s.any recomendations ?

Here we go...

But if you are int he 29-32 ft range, twins are the only way to go IMO.

agreed!! had a 28 big hp single for about 4 months. great boat dont get me wrong but i like the twins way better. the dependability with stock 502 mags in unbelieveable. the extra weight makes it handle incredible in rough water. drive both before you make a decision. my .02

If it has to run in the 70s you can find a 29 or 30 with a single 500efi or 525efi that will be very dependable and get you to the speed you want. Half the maintenance and gas.

You also can't argue with that logic either.

Once you have owned a boat with twin engines you will never own another single engine boat. The docking and manuverability with twins is worth the price of admission. I currently have a 27' Hallett with twin Mercruiser Scorpion 377" small block Chevys. It uses less gas than the same boat with a single big block would use. My average fuel burn is 8-12 gph.
My $0.02

You just can't idle back to shore/trailer with one if it breaks!

Where are you boating?

Do you have a 1/2 ton or 3/4 -1 ton tow vehicle. Do you tow it or keep it at a dock?

My boat is close to '32 LOA and runs uppers 70's w/525efi.

The only reason I would prefer twins is the reliability.

If were talking about inboards a single engine with big horsepower, easier to work on and less fuel use so you can cruise around all day without breaking the bank. Just my opinion

If you're comparing apples to apples (speed, distance equivalent), there's no way

Make me an offer on mine! Wife and I decided to go to a cruiser for a while and I want a cat so this one needs a new home!
2002 Formula 292 Fastec twin 350 mags. will run 68-69 consistantly and has seen 72 or so on GPS from time to time as well. Very dependable boat and comes on a brand new aluminum triple axle trailer with EOH brakes.

send me a PM if interested and can send you more pics as well.

I will say it again you cant coast in on one motor.

yup i had a single for 4 months. towed 12 hours from buffalo ny to lake cumberland for the poker run last year. splattered a drive half way through the run. an hour later i got lucky and tim brown (oso member) stopped and was nice enough to give me a 2 1/2 hour tow back to the launch. threw on the spare drive and finished the weekend. got home and sold the boat and bought twins. better cruising and top end. way better on fuel. and stock power the maintance is minimal vs the upkeep on a big hp single.

not bashing singles cus there are some bad a$$ singles that fly with mild power...warlocks, 29 fountains, ect. but from here on out i will get home on my own power

+1 on the better fuel consumption with twins over a single. I have personally experienced it. Yes, maintenance is double, but i do my own service on my outdrives and motors.

tom

maintance is cheap. oil, filters, impellers even plugs wires and such. that stuff is peanuts. hell all that combined is cheaper than a drive coupler that a big single eats. or drive for that matter.

wave crushers like a pantera take big power to run in a single. the faster hulls definately take less power to get moving but you loose a little ride in the big water. it depends on what you boat in water wise.

the twins def dock easier too

I would, my single gets about 2 mpg at 40mph. A couple of twins I have run with get around 1.4-1.5 mpg at the same speed.

Cant argue much with the "half the maintenance part" though:lolhit:

Quote:
Originally Posted by tjred
Half the maintenance and gas.
I can!

Blue engines need top end rebuilds at 250 hours and full builds at 500.

Compare a couple of small blocks that won't need to be touched and do the math. The extra yearly stuff is cheap compared to a top end build on a blue engine. Also, a couple of black engines are easy on drives Vs. single blue being tough on one.

Bottom line is the up front cost and maintenance through the years ends up being a wash at best... if you start blowing drives twins actually win.

it depends on where you boat.If you staying on lakes and rivers, there will always be someone helping out if the single breaks. I'm boating on rivers and lakes, but on the ocean, there's a 26 mile stretch between my destinations and I wouldn't want to float for ever until Seatow shows up, hence owning twins. Someone said no way to DKhans's post on fuel economy with his 27 Hallett, running two 377 Scorpions. I have 377 black [ 6.2 MX ] engines in my 257 Mirage with SmartCraft. WOT @ 5000 with B1 26P props, fuel flow scan shows 20 gal per engine. Never seen a big block single engined boat run less than 40 gal per hour at WOT, especially carburated ones! I would choose twin small blocks in boats 33' and under.There's more room between the engines to work on, compared to having twin big blocks. Anything bigger than 33' ,I'd definitely go big blocks.

http://www3.telus.net/spectrasonly/E...ect%20complete

http://www3.telus.net/spectrasonly/M...06,2%20L%20MPI

Dave's quote is pretty close. His boat is 27' , mine is 25'7. His quote 8-12 gal/hr average, [don't know at what speed] my average is 8 gal per/hr at 3000 rpm, cruising at 40 miles per hour, going to 20 gal/hr at 5000 rpm, 75mph on the GPS Gaffrig speedo.
I'm sure Dave meant 8-12 gal/hr per engine.

I limped back to the launch ramp on the port engine when this happened. A testimony for having twins and external rams to keep the drive pulling out , http://www3.telus.net/spectrasonly/broken%20bellhousing

A carbed 454/330 is about 25gph, the carbed 502's are about 33gph, this is stock. #'s straight from the manufacturer. I have no numbers on blue motors. I hate gallons/hour, why not use standard mile/gallon, though I suppose this would make people use division...challenging I know. ;) Obviously a boat traveling twice as fast using the same amount of fuel is more efficient.

Not comparing our go fast boats to a Grand Banks that does 2.5 gal/hr, or comparing a Hatteras that goes .5 miles per gallon.

So,you're telling that a 502 carbed engine only burns 33 gal/hr compared to a EFI engine @WOT!

Fountain 29 Fever Test Result Highlights
Top speed for the Fountain 29 Fever is 76.0 mph (122.3 kph), burning 39.8 gallons per hour (gph) or 150.64 liters per hour (lph).

Best cruise for the Fountain 29 Fever is 30.2 mph (48.6 kph), and the boat gets 2.86 miles per gallon (mpg) or 1.22 kilometers per liter (kpl), giving the boat a cruising range of 361 miles (580.97 kilometers).

Tested power is 1 x 500-hp MerCruiser 500 MAG EFI.

Hook up a fuel floscan to that 502 and see what real time test show.

i cruised from cleveland to marblehead 60 miles 1 way ,around 60mph at 3500rpm. got a little over 2 mpg with twin 502 mag efi's. 28ft pantera. same boat with a 650hp 548 single got 1mpg and cruised at 60 @ 4700 rpm. twins really cut down on prop slip and really become more efficient than ya think.

2 1/2 hours?:eek: Tim Brown deserves some sort of award:ernaehrung004:.

Michael

I have a flow meter on my boat, it reads just over 40, built to 540 horsepower. The stock 502 read just about 34. I'm looking at the paperwork that came with my boat and those are the #'s they quoted (they have fuel flow in 500rpm increments) Obviously a 500hp 502 will burn a lot more than a 502 415, so I'm not sure what you are saying.

Saying all BBC's burn 40 gallon per hour is a bit silly that's all.

I happen to think gallons/hour is useless. I don't know what a grand banks is and I have no idea what you are talking about with reference to the first thought between boats....the boat with the highest mpg is the most efficient, if that's what you are saying I agree with you. Just because it uses less gallons per hour, does NOT make it more efficient.

Unless you are going or a 3-hour tour, and it doens't matter how far you actually go :D

There you have it .Agree on the efficiency part.

I have a single 32 and it can be a real handful around the docks, especially if it is windy outside. A twin gets you on plane faster, and splits the work between two engines and drives, hopefully giving them a longer life. Double the routine maintenance is actually pretty cheap. My sinle 32 w/502 gets about 1.75 mpg.

he said "no problem... cooler is full and i got plenty of cigars.. throw me a rope"

That's a boater right there...

This thread may go on forever...

But it's fun, so here's another wrinkle. When Mercury introduced the 525SC, a boat magazine did a test of two 29 Fountains, one with twin 260 HP small blocks, one with the single. All I remember is the single engine boat went 10 mph faster. It was 1000 lbs lighter and had less gearcase drag. That's where efficiency comes from. Of course running a blower engine rich will mess that up in a hurry.

At some point a single prop doesn't have enough blade area to do the job. Maybe that's when you have to use two props/drives/engines. Or a Bravo III...

[QUOTE=spectras only;3779957]Dave's quote is pretty close. His boat is 27' , mine is 25'7. His quote 8-12 gal/hr average, [don't know at what speed] my average is 8 gal per/hr at 3000 rpm, cruising at 40 miles per hour, going to 20 gal/hr at 5000 rpm, 75mph on the GPS Gaffrig speedo.
I'm sure Dave meant 8-12 gal/hr per engine.

I limped back to the launch ramp on the port engine when this happened. A testimony for having twins and external rams to keep the drive pulling out

I check my fuel burn at each fill up. I average 8-12 gph total for both engines. I am boating on Lake Havasu and there is a fair amount of ideling in and out of the harbor, so that lowers the fuel burn. If I just go to Catalina and back so it is all cruising (usually 3000rpm) which is about 43mph my fuel burn is 15 gph total for both engines. That is about 2.5 mpg.
The boat is pretty light and therefore not the greatest for rough water, but it does perform well. Top speed is 5200 rpm and that shows 82 mph on the pitot speedometer, but the Nav GPS shows it to be more like 75 mph. If I run it hard, which I have only done one time 4,000 rpm is 60 mph on the speedo, don't know what the gph would be.

The boat you pick will depend on what you want to do.

I had a 29 Kryptonite and with a single 550hp motor saw low 80's all day long.

The Kryptonite was a low slung sit down boat that was light and had a basic cabin. It ate up rough water and the race boats dominated the F1 class so you know it is a great handling/running boat. That said, it does not have the cabin or the entertaining space of a Formula, Baja, etc.

If you want a big cabin and more luxury ammenities than the size and the weight go up and you will probably need a twin engine boat. Double engines require double maintenance but also provide the security of getting home on your own power.

Any way you look at it, you can't put a price on FUN. And being on a boat with 1 engin or 2 is better than being on shore!!!