Adequate 8.1S I a440?

[Hampton]

Our friend's 2004 390 with 8.1S gassers was a pig. 19mph while sucking down 30 gph (or worse). The new owners don't even take it up on plane anymore (mistake, IMO). They idle it around everywhere they go. They don't go too far.

 

[RollerCoastr]

do you mean 410EC or 410DA.....

Dom - good catch. Yes, I was referring only to DA's.

Rob, in my experience, yes, a gasser isn't any more likely to fall apart in snot than a diesel is. The torque advantage is often, but not always counteracted by a much less heavy stern. You mentioned how loaded your boat is. That's an issue with diesel v-drives. Depending on how the waves are hitting though, a heavy stern CAN be an advantage. I can ventilate my props in just 5 footers. Not fun, and a diesel is much, much less likely to suffer that.

And in case it wasn't clear: my position is that a gasser 40DA is a fine choice for many people, and when properly tuned and run, is far from a pig. HOWEVER, with the 420/44DA's, the availability of 6C's make a much wider delta between gas and diesel performance and is a compelling arguement for going diesel.

 

[RollerCoastr]

John, again, I'd sink a boat that performed like that! Too bad so many people accept poor performance because they're told they should, instead of figuring out what's wrong with their boat.

(at 19mph, I'm not even on plane. who is so underinformed that they think their boat cruises off-plane???)

 

[bluebelly]

Wow , So not to add fuel to this fire. U guys are saying a fully fueled , fully loaded 44 in gas can go out in the ocean on a snotty day and actually get to its destination with out blowing itself to pieces ? Im a doubter for sure. Like I posted before we tooko a 40 da in gas 8.1sho and the boat was a pig in the bay. Waves ( small chop ) took its toll on our headway. I cant fathom those same motors in a larger wider boat. Ur paying a ton of money for a bay boat. ( fair weather boat ) with a questionable engine life expectancy. That said I cant imagine my boat in gas. We go away for weeks at a time the boats so loaded with gear I no longer have a water line. Why would u settle for something that the majority is telling u will disapppoint you ?

Rob

$70000 to $80000 is reason to settle. The person who made this thread needs to state how or where he or she is going to use this boat. Maybe the majority that is speaking do not have credibility since are speaking without actually having owned the boat in question. I am only lateralling my real life experiences with having put about 900 total combined hours on both a gas and a diesel powered 420/44. One thing that is frustrating about these online forums is that people tend to exercise opinions on subjects they have no experience on.

 

[osd9]

I rode up the Delaware a few years back with a 390DA gasser....the 40DA.....following me. We hit some major snot and had to throttle way back. I was/am able to hold plane down to about 15-16 knots. The 390DA couldn't come close to holding plane at that speed. The torque of the diesels equals bigger wheels and lower trans ratio reduction. So, we both had to go a little faster than I would have preferred.....and the ride quality suffered. Plus, we had to stop twice for fuel....for the 390DA....not my 410DA.

 

[Alex D]

Conversation heatin' up a bit there ...

 

[Hampton]

There is no doubt that there are applications for almost all combinations. Most of us like a boat that is well powered, if not over-powered. Most of us would consider that boat underpowered, and therefore not a great choice. There are exceptions. Even for those exceptions, re-sale can be a real bear.

As has been stated many, many times on this board, you will probably never ever break even on the cost when comparing the diesels to the gassers, until the day you sell it - then, pocket all those years of efficient running and a quick-re-sale.

 

[Alex D]

There is no doubt that there are applications for almost all combinations. Most of us like a boat that is well powered, if not over-powered. Most of us would consider that boat underpowered, and therefore not a great choice. There are exceptions. Even for those exceptions, re-sale can be a real bear.

As has been stated many, many times on this board, you will probably never ever break even on the cost when comparing the diesels to the gassers, until the day you sell it - then, pocket all those years of efficient running and a quick-re-sale.

Well said! Thank you Hampton!!

There is no doubt in my mind that I would like to ahve diesels in anything bigger than a 340DA, but I do appreciate and agree that some, maybe all, lake boaters havea valid case for gassers even in a 440DA. I see evidence for that all aorund me on the lake where boats are movable condos on the lake or weekend party platforms. The use is just very, very different than coastal boaters. My direct slip neighbor has a '84 390EC and never goes beyond displacemetn speed with that boat. We have three 370DBs in the marina, two with gassers (imagine that!) and one with 3116 cats. I have never seen any of them run theirs up on plane ever.

So to each their own I guess. :thumbsup:

 

[gerryb]

I have never seen any of them run theirs up on plane ever.

I get what you're saying and don't disagree with your point, but what a shame not to have the experience of running at 30MPH+...

 

[Alex D]

I get what you're saying and don't disagree with your point, but what a shame not to have the experience of running at 30MPH+...

Couldn't agree more. I idle out of the marina and the cove and then throttle her up running between 27 and 30 mph until we get to our favorite spots. But its only a 6 (closest anchorage) to 10 mile (farthest anchorage) jaunt in any case. We only put about 120 hours on her in four seasons.

 

[DeltaEx]

I Just bought my 1998 370 EC a year ago and the old owner had just repowered with the 8.1 HOs. Your right they are PIGS from hell! I cannot take this boat on any trip. I am now in the process of talking to my locale marina about Yanmars or Cummins. The 8.1s do not perform to half of what they claim JUNK JUNK JUNK !!!!

 

[Hampton]

I Just bought my 1998 370 EC a year ago and the old owner had just repowered with the 8.1 HOs. Your right they are PIGS from hell! I cannot take this boat on any trip. I am now in the process of talking to my locale marina about Yanmars or Cummins. The 8.1s do not perform to half of what they claim JUNK JUNK JUNK !!!!

Now easy there, boy. The 8.1's are awesome motors. They meet all manufacturers specifications. They may not be a good match for your boat, but Merc didn't make you buy that boat, so where does the fault really lie?

 

[douglee25]

I Just bought my 1998 370 EC a year ago and the old owner had just repowered with the 8.1 HOs. Your right they are PIGS from hell! I cannot take this boat on any trip. I am now in the process of talking to my locale marina about Yanmars or Cummins. The 8.1s do not perform to half of what they claim JUNK JUNK JUNK !!!!

What rpm and fuel burn are you seeing at cruise?

I wonder if it's propped correctly with the new motors? My guess is they kept the same props that they used with the 7.4's when they probably could have gone with a bigger wheel due to the increased torque. Now your engines are buzzing to keep the boat on plane all the while burning excess fuel.

Doug

 

[tdappleman]

I Just bought my 1998 370 EC a year ago and the old owner had just repowered with the 8.1 HOs. Your right they are PIGS from hell! I cannot take this boat on any trip. I am now in the process of talking to my locale marina about Yanmars or Cummins. The 8.1s do not perform to half of what they claim JUNK JUNK JUNK !!!!

Seems strange - did a search and found the brochure for your boat. http://www.searay.com/boat_graphics/electronic_brochure/company1729/1C1_27_74DERNWQG960.pdf

The standard engine was the 7.4MPI with 310HP while the 8.1's have 420HP. Seems like an additional 110HP per engines (220 total) would help.... Are your engines running correctly and at the right RPMs? Might need to investigate bottom conditions or prop choices before you make the expensive jump to a diesel repower. I wish those 8.1's would fit into my 'lil boat!!:grin:

 

[ImpulseIII]

Don't forget to consider resale with diesels. You will recoup a lot of the initial expense difference when (if) you sell or upgrade.

 

[Robski97]

Wow I got dissed and didnt even see it ... ughh... I guess i too should list my dozens of boats purchased , sold and sunk... That will give my post more credibility ???

Oh please...


Rob

 

[Hampton]

Wow I got dissed and didnt even see it ... ughh... I guess i too should list my dozens of boats purchased , sold and sunk... That will give my post more credibility ???

Oh please...


Rob

???

 

[bluebelly]

Wow I got dissed and didnt even see it ... ughh... I guess i too should list my dozens of boats purchased , sold and sunk... That will give my post more credibility ???

Oh please...


Rob

Rob,

You are right, I apologize. I obviously had way too much to drink that morning. I don't even remember posting that.

 

[Robski97]

No problem... Just one them days here too....


Rob

 

[Brutus C Paw]

I don't have a 44, but the 38 with 8.1's. I find the biggest issue is when cruising with other boats, generally they are waiting on me. When we go, it's usually fully loaded (transom full with Weber grill, chairs, etc and couple of cases of wine in the cabin) and I can get about 26.5 mph at 3800 rpm, maybe 27 when we get a little fuel burn. It's OK when we go alone, but with a group, especially with smaller stern drives, I feel I have to push too hard to keep a happy medium with everyone else; I prefer about 3600 which is more like 24 mph.

I've never had an issue with waves or head winds, but have to admit that if its more than about 3 to 5's on Lake Michigan, we stay put.

Just as FYI, my sales guy at Skipper Buds says they won't order a 44 without diesels, too much boat.