23" Scepter I/O performance

[BigLew]

Happy New Year to all.

I was out with the dog this morning and looked over at my Scepter that I fervently hope will become a WIP (work in progress) soon. She has a 140 gal fuel tank, tabs, etc.; much like most others. I have a 260 HP volvo penta out drive on it and intend to keep it that way. I DO intend to replace the motor however and am thinking about taking up over 300 HP. Someplace between 315 and 350 depending on whether I go normal carb (somewhat repairable on the water if it should fail) or Injected (which I understand little about and less in terms of repair.) I likely may adust the fuel tankage to something a little more realistic for my purposes, say fore and aft mounted dual tanks of say 80 and 50 with the smaller mounted aft and not kept empty unless I should feel the need to carry more fuel at one time for whatever reason. By my calcs that would give substantially over 200 mile range. I live in norhern Mass. and would likely not venture more that 40 miles offshore, but I may venture as much as far down to Long Island/New York or up to Camden, ME.

My question is what are real perfomance numbers for various power options. It is no speed demon, but in the past I was cruising at 21-23 @ 3200 RPM and about 32-34 WOT. That may have been a bit conservative, but the extra two carb barrels weren't open at cruise and I was getting about 5-7 gal/hour burn rates overall.

I hope to hear from all and I wish everyone of us a better year, no matter what your 2011 was like. Be well!

[pelican]

the multiport engines are definatley the way to go - smooth acceleration,"turn key" starting,alarm systems keep the engine from self destructing...

last volvo repower i did - the distributor had a "left over" 5.7 gxi engine - i got a deal that was hard to beat.
i'm not a fan of replacing "long blocks",or rebuilding what's existing - i use complete "drop in" engines...reason being,you're pulling an engine that's basically worn out - the exhaust system - manifolds and risers,tin ware,pulleys,fuel system parts,electrical parts - these are all old too...transfering these old parts,onto a "rebuilt" block,or,replacing these parts and installing them onto a "rebuilt" block - this all starts to add up,and,in the end,you're got a "rebuilt" block - most of these blocks carry a very limited warranty.purchasing a new,drop in engine,it carry's a mfg's full warranty,it's new,as in new,everything on the engine is new,and,in most cases,it actually works out to be only a few dollars more.the idea of a repower is to "up grade",make the boat perform better than it did previous...
for what it's worth: the multiport injected engines have proven to be very trouble free - i've repowered numerous boats with these engines - no failures on any...

my own potter built -
it was repowered in '01 with a 5.7 merc magnum MPI with the horizon package - bravo drive.that package has proven to be incredibly efficient,and reliable - ZERO problems - cruise speed,with a full load - 150g fuel,loaded to fish offshore for the day - 22-23kts...that rig's been ran and ran hard...

[BigLew]

Thank you, Jim. I take your points very seriously.

MPI vs. Normal aspiration is attractive and is definitely in the mix for a couple of reasons. First, it seems to be easier and quicker starting, not to mention more efficient in general. It also provides more and higher HP options for about the same money. My one real hang up is on-site repairabilty. I have esperienced sudden engine failure in the past and often it has been repairable on the spot. Stuck thottle plate, water acculmulation in the float chamber showing up as you crank up the rpms - out of close range to a dock, etc. MPI does not seem to be the same situation or maybe its just my lack of familiarty with it-NONE!

Your performance numbers are of interest. Clearly there is some expectation of increase on my part. I was thinking that going from 260 to say 330 would put me in the 26-28 rrange on cruise and the higher 30's, say 37-39 wot. Am I being unrealistic? The cruise number is the more important to me overall.

PS

Jim, I totally agree with a new engine; from fuel line to batteries to bell housing! The drive is up for grabs. It is rock solid as it sits and has a stellar history. That said, for the right reasons and the right $$$ it may be in the mix as well.


I'd also like to hear from others on this as well. Say "Entourage", " Water Rat" or someone else runnig a Scepter I/O set up?

I do know one thing. Being up north here and dealing with the local area, i.e. the Merrimac River inlet and a LOT of 2+ ft. chop as I do, I will not be going to an outboard. It is a personal thing and I just like the weight being down low in the bilge.

[floorboy]

I have a 260 hp volvo 280 drive. I dont know why but I hate it performance wise. It is the oem motor/drive that came with the boat.(freshwater) Runs great never had any issues with it so I dont know why I hate it, just do. They are suppose to be really good drives though.

When I repower I will be going with an mpi enigine drive package. (I need to do the transom anyway)

I dont pay too much attention to the numbers but I know I run 30-33 mph on cruise and can top out about 37-38. A buddy just bought a slickcraft (ugh) with a 210 hp mercruiser with an alpha drive and he can smoke me...... till it gets rough.

[bigeasy1]

I have a 74 23 Tsunami powered by a 260 hp 350 Mercruiser with an Alpha drive.Wide open throttle I get about 35-36 MPH on the gps.I cruise at about 25 at 3400 rpm.Now if I can just get my tach to perform properly.

I'm not all that happy with the top speed,but oh well,in every other aspect it performs flawlessly.
I spent countless hours searching for the right prop.and ended up with a 15x17 Mirage plus stainless prop.This has been a good performer for me.There is no lag at all to get on plane,and it does well across all ranges.
If money was no object when I powered it,I would have gone with the 383 stroker and a Bravo Three drive.I think the Sceptres/Tsunamis need much more power in the I/O configurations than 260hp.

Lew,& Floorboy,- Volvo has some 350 5.7's that are pretty sweet in 300 & 320 hp models available with carburetors or fuel injection.Pretty nice if you don't mind spending 10-12 grand.

[floorboy]

Prop selection is one of my main bitches with the volvo.....Do they make any???? I can't find them if they do.

[gofastsandman]

Happy New Year Big Lew. I`m still waiting for my Citgo sign.

Cheers,
GFS

[DonV]

Hey Lew, be careful with that Citgo sign!! Sandy will be looking for it in the Bahamas when he takes his "slacker" over later in the year at the gathering. We want to make sure he can see it from far away on the water to put his mind at ease!

[BigLew]

Originally Posted by DonV

Hey Lew, be careful with that Citgo sign!! Sandy will be looking for it in the Bahamas when he takes his "slacker" over later in the year at the gathering. We want to make sure he can see it from far away on the water to put his mind at ease!

Don V,

ALWAYS remember, "Possession is 9/10ths of the law!" The Citgo sign is safe and will be visible at ALL Red Sox games in the foreseeable future!!! GFS can take it to the supreme court if he wants, but it is NOT going anywhere! (Do you hear me Sandy, my friend!)?

I think it was Floorboy who mentioned availability of props for the Volvo's. I too, have had some challenge in finding a variety of available props over the years. I have a 15 x 17 as well, but they are cupped. I spun the first one and decided to replace it with a cupped verision. It was adequate, so I had the first one cupped when I had it recon'd. It had had a few dings in it and I thought it might be nice to have the confidence of having a replacement onboard - but haven't needed it!

My biggest complaint is that the stern just seems to sit deeper than it should! It has been a while, but I remember that at cruise the outer aft corner was still 2-3 inches below the surface, though the outer side was not wet. On Plane the the stern corners were below the suraface but "dry" as the water exited out and back. (Is that clear?) I will say at this point that I had to step back there and really look, so my 200 +/-lbs. were back there at that moment!

I think if you look around you will find more options than you minght think are out there. Speak with some of your local prop guys/shops and I suspect they will tell you about how they can get you anything you might want. Beware though, the price might be higher because of the lower volume- Mercs out number V/P's 10 :1 at least! Original manufactures want to keep theiy selling price down, so more are inclined to go with the merc drives.

That doesn't change that the Volvo's seem to have a better long term reliability reputation and a very loyal following.

[BigLew]

Originally Posted by DonV

Hey Lew, be careful with that Citgo sign!! Sandy will be looking for it in the Bahamas when he takes his "slacker" over later in the year at the gathering. We want to make sure he can see it from far away on the water to put his mind at ease!

Don V,

ALWAYS remember, "Possession is 9/10ths of the law!" The Citgo sign is safe and will be visible at ALL Red Sox games in the foreseeable future!!! GFS can take it to the supreme court if he wants, but it is NOT going anywhere! (Do you hear me Sandy, my friend!)?

I think it was Floorboy who mentioned availability of props for the Volvo's. I too, have had some challenge in finding a variety of available props over the years. I have a 15 x 17 as well, but they are cupped. I spun the first one and decided to replace it with a cupped verision. It was adequate, so I had the first one cupped when I had it recon'd. It had had a few dings in it and I thought it might be nice to have the confidence of having a replacement onboard - but haven't needed it!

My biggest complaint is that the stern just seems to sit deeper than it should! It has been a while, but I remember that at cruise the outer aft corner was still 2-3 inches below the surface, though the outer side was not wet. On Plane the the stern corners were below the suraface but "dry" as the water exited out and back. (Is that clear?) I will say at this point that I had to step back there and really look, so my 200 +/-lbs. were back there at that moment!

I think if you look around you will find more options than you might think are out there. Speak with some of your local prop guys/shops and I suspect they will tell you about how they can get you anything you might want. Beware though, the price might be higher because of the lower volume- Mercs out number V/P's 10 :1 at least! Original manufactures want to keep their selling price down, so more are inclined to go with the merc drives.

That doesn't change that the Volvo's seem to have a better long term reliability reputation and a very loyal following.