Island Gyspy 210 hp / 315 hp

Why would a new boat owner in 2005 have requested a 315hp Cummins (upgrade) over the then standard 210hp Cummins. Taking into account this is a 32 foot craft ???

Hard to imagine why, especially as the sellers "new" boat is 40 ft with a 230hp Cummins. But he didn`t commission the IG, that was the lady who originally owned it.
Wonder who was selling new Island Gypsy boats in Sydney in 2005. Maybe Mark Halvorsen, I think he was still at Bobbin Head then. But,selling Halvorsen and IG?

Our 2001 IG 32 has the 315/330 Cummins in her. Have the same question as to why original owner opted for it. Not any additional speed over a friend's IG 32 that had the 210 and we have a turbo and aftercooler to maintain and be concerned about.

Because he liked pushing a big bow wave.

David

Probably a Freudian compensation sort of thing.

dwhatty said:

Our 2001 IG 32 has the 315/330 Cummins in her. Have the same question as to why original owner opted for it. Not any additional speed over a friend's IG 32 that had the 210 and we have a turbo and aftercooler to maintain and be concerned about.

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I suspect the the 210hp boat was propped right and the 315/330hp boat was/is overpropped.
Also the engines could be the same size .. one w a turbo and the other w/o. A very knowledgable man in the marine propulsion business told me to pay more attention to the cubic inches displacement than the hp rating. Lastly the power rating on engines comes from many sources and countries. My Mitsubishi engine comes from Japan but is rated by Vetus at 42hp, Westerbeke at 44hp and by Klassen at 37hp. Lots of different ratings.

dwhatty said:

Our 2001 IG 32 has the 315/330 Cummins in her. Have the same question as to why original owner opted for it. Not any additional speed over a friend's IG 32 that had the 210 and we have a turbo and aftercooler to maintain and be concerned about.

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Thanks David the broker wants considerably more for the 315 over a previous sale of a IG32 sistership 210 based on HP alone .

I will now offer even less based on your experience

Was the Cummins 210 NA?

Bruce is'nt the na Cummins engine 115hp?

Nomad Willy said:

Bruce is'nt the na Cummins engine 115hp?

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I don`t know Eric. Posts seemed to imply the 210 was NA.I`m happy with NA Lehmans, but Cummins have a great reputation. Still, the IG32 can`t use the 315hp. Cross reference this thread: http://www.trawlerforum.com/forums/s3/engine-size-vs-hull-speed-30230.html#post520593
IMO the best IG32 engine set up was twin 80hp Lehmans.

I don't know much about Cummins. But I do know there is a 115hp Cummins 6 cyl engine. Must be NA too.
And I think a 120hp increase in power should definitely make an IG go faster. It has the flat and straight run aft to allow that to happen .. all other things being fairly normal.

The Cummins 210 hp has a turbo but does NOT have an aftercooler. To get more power than 210 the aftercooler is then needed.

I don't know about the 115 but there was a N/A at ~160 which is still available under the recon program.

I don't think the I.G were full displacement hull, rather semi so the extra HP may get it on plane, maybe a slow plane. Don't know.

The 115 hp 5.9 NA Cummins B is not normally marketed as a marine propulsion engine. Industrial application - pumps, gensets, etc.
As Willy pointed out above, beware of the high hp rating being overpropped.
Nothing wrong with having more hp than you need, besides a rather small weight penalty, and a few more maintenance items.
Never heard of a diesel blowing up from running slow...

kapnd,
That seems to be the thinking here.

C lectric said:

I don't think the I.G were full displacement hull, rather semi so the extra HP may get it on plane, maybe a slow plane. Don't know.

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You're right about the I.G having an SD hull but my old boat, SeaHorse II, had a Cummins 330B in it and still would not get on plane! It did make all the published numbers so it wasn't over or under propped.

I have a pair of the 160's as generators, 1800 RPM, they are turbo, but not aftercooled.

Codger2 said:

You're right about the I.G having an SD hull but my old boat, SeaHorse II, had a Cummins 330B in it and still would not get on plane! It did make all the published numbers so it wasn't over or under propped.

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I`d expect high fuel usage for little gain. The IG SD hull is more D than S imho. I still say the IG 32 has no real use for 315hp, 210 hp would be plenty.

Nomad Willy said:

I don't know much about Cummins. But I do know there is a 115hp Cummins 6 cyl engine. Must be NA too.
And I think a 120hp increase in power should definitely make an IG go faster. It has the flat and straight run aft to allow that to happen .. all other things being fairly normal.

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You're right on the engine. The 115 is NA. Remwines (Bob) just installed one in his DeFever 40. He found a great deal on a barn-find posted on Craigslist.

C lectric said:

I don't think the I.G were full displacement hull, rather semi so the extra HP may get it on plane, maybe a slow plane. Don't know.

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Codger2 said:

You're right about the I.G having an SD hull but my old boat, SeaHorse II, had a Cummins 330B in it and still would not get on plane! It did make all the published numbers so it wasn't over or under propped.

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BruceK said:

I`d expect high fuel usage for little gain. The IG SD hull is more D than S imho. I still say the IG 32 has no real use for 315hp, 210 hp would be plenty.

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Having enjoyed a few days on SeaHorse II, I saw her SD hull in action. I saw many similarities with my Californian 34 LRC, powered with twin 85 HP Perkins on a semi-displacement hull. Our speed ranges were similar and our fuel burn was close but favored the single IG-32. At anchor, they both behaved similarly.

Then I got the chance to ride on chc's (Chris's) Californian 34 LRC Scooter, with twin Detroit 250s! We took her out for a spin to "see what she'd do!" We topped out at 23 Kts which was very impressive!! The deck angle was so high, though,that visibility from the lower helm was hindered. IIRC, the intermediate speed was in the mid-teens. That was very comfortable and easily achieved, albeit at a cost in fuel $$. Even though the total HP's were different by 185 HP, I was impressed by the performance of a SP vs SD hull. Up to this point, I always considered them variations of the same concept. After this, it seems to me that there is quite a difference.

210 and 330 are the same engine block. Both turbo, but the 330 has a sea water aftercooler and the 210 has no aftercooler at all.

I do like the P7100 pump on the 330 better. Much more crisp injection and very nice governor action compared to the CAV pump. In fact the 330 gets better hp/gph than the 210 in midrange, but not sure if that holds way down low.

If both engines are making the same say 40hp at slow cruise, burn rate will be nearly identical and the 330 might be better.

Aftercooler remains maintenance headache, which is only significant downside I see.

I would not spec a 330 for that boat, I'd stick with the 210.

"If both engines are making the same say 40hp at slow cruise, burn rate will be nearly identical and the 330 might be better."

For 40 HP the little JD would be an even better choice, as at least it would be 50% loaded.

Even with out a BMEP or fuel map the JD should have lower fuel burn than 210-330 HP run at 15% power.

I have never read of an engine that was efficient at that minor power level.

A displacement boat can only use so much power , after that its a waste of space , weight and maint bucks.

The IG and Cal hulls are SD but much closer to planing than displacement.
The think that keeps them acting like SD is weight and at least in the case of the IG .. a big draggy keel. Maybe the Cal has that too but I don't remember. Comparing the four a GB and a NT are much closer to FD than the IG and Cal.

So with more power an IG should step out and go faster. If the bottom to transom edge is quite rounded and not sharp .. that would prevent planing or a little faster speeds. The roundness of that edge would suck the stern down and back.

Al yes 500hp and 23 knots on a Cal is what I'd think would happen. Anyone have 500hp in an IG?

Nomad Willy said:

The IG and Cal hulls are SD but much closer to planing than displacement.
The think that keeps them acting like SD is weight and at least in the case of the IG .. a big draggy keel. Maybe the Cal has that too but I don't remember. Comparing the four a GB and a NT are much closer to FD than the IG and Cal.

So with more power an IG should step out and go faster. If the bottom to transom edge is quite rounded and not sharp .. that would prevent planing or a little faster speeds. The roundness of that edge would suck the stern down and back.

Al yes 500hp and 23 knots on a Cal is what I'd think would happen. Anyone have 500hp in an IG?

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I agree with most of your points. I do think beam to length does come into play even for planing and semi planing boats. IOW, a short fat hull is not gonna go thru the water very easily...regardless of its shape. I think THAT is the biggest reason this IG hull struggles....and of course weight. The Mainship 350/390 suffers the same fate. Fat hull. The marketing department build the interior for space and THEN they have to wrap it in fiberglass. What I call building a boat from the inside out.

Mr Baker I do belive you nailed it.

I failed to mention that and it's certianly a factor. That's one of the main reasons the NT slides along so easily. The're a bit narrower than their brothers. And they have some rocker too. Since they mostly have keels a lot of trawlers could use some rocker. Something you missed though IMO is that the Californian is probably an average L/B ratio .. probably even on the long side. But her run almost from the bow is very very straight. And not much dead rise for either the IG or thr Cal. The Cal is a bit like a long and somewhat narrow board bent slightly down in the middle. That should give them a "long wheelbase" effect. Lots of pitch stability. And that feature is'nt present in the IG. But the IG slices the water nicely in her forefoot whereas the Cal pushes the water up and even fwd into a magnificant bow wave worthy of a huge fountian.

Good point re: the L:B ratio. The 34 has a 12.4 ft beam.

Here are a couple shots of FW at WOT 10 Kts. I see the hull more as a slicer than a puncher.

As a multihuller for decades , yes the L/B ratio does matter ,
after you get above about about 6-1.

The boat with 3-1 will have less drag at most slow cruise speeds as it will have less surface area (at same weight) as a 4-1 boat.

When one wants speed, light weight and good L/B ratio make it possible to create a smaller bow wave , so easier to climb up on.

Most catamaran folks chose to cruise as slow as a monohull as they don't want the fuel bill for the higher speeds.

A skinny monohull will usually have a more sea kindly ride than a beach ball.

And the Mainship 350/390 has almost 2 more feet of beam with almost the same waterline length as the Californian 34. I know a lot of folks bought that boat(MS350) thinking they were gonna get planing speeds out of it. Mainship even marketed it as a "Fast Trawler" and it wasn't fast at all. With that 3116 at WOT it MIGHT make 12 knots and that is with the thing screaming. Back off any and you are down to a very inefficient 9-10 knots and off plane pushing a mountain of water. So they are "forced" to go in the displacement speed range with all that extra power. That boat with a 135hp Deere or American Diesel or any 100ish horsepower engine would be perfect. And for the people that want to plane, jam a C series Cummins in there. The twin 240hp version of the MS350 would easily cruise at 14-15 knots with a max near 20. You just had to clear that hump. And 300-370hp just wasn't quite enough.

Even the twin 200hp Volvo versions got up on plane.

Well further probing I find the original owner requested the 315hp on advice from the builder that the 315hp would gain 3knots at WOT He must have been a good used car salesman for one to part with a extra $30000 PMSL

Maybe. I had an old Mainship 34. SD hull. OEM power was a Perkins 160 hp.
I repowered with a Cummins 6BTA at 270 hp.
What a difference with the extra 100 hp. Cruise speed went from 8 kts to 14 knts. WOT went from 10 to 18.5 kts.
It turned a great boat into an awesome boat.
Fuel consumption when measured as miles per gallon stayed roughly the same at the 2 cruising speeds.
So to answer the question no contest choosing 315 over 210.

"The twin 240hp version of the MS350 would easily cruise at 14-15 knots with a max near 20. You just had to clear that hump. And 300-370hp just wasn't quite enough."


I never had or cruised with a Mainship 350 and would never have guessed on this outcome. Very interesting that they require that Hp to reach those speeds - thank you

"Maybe. I had an old Mainship 34. SD hull. OEM power was a Perkins 160 hp.
I repowered with a Cummins 6BTA at 270 hp.
What a difference with the extra 100 hp. Cruise speed went from 8 kts to 14 knts. WOT went from 10 to 18.5 kts."


Many years back we had a 1978 34 as well with the 165 Perkins in it. We did not have it too long but it made us aware of all the 34's around the sound. I think we may have seen your boat on the Northport dock a number of years back. We get to Mystic often just about our favorite destination.