Trojan Boat Forum

We're considering moving up in size to an 11meter or 12meter convertible, and would like to know what the actual draft is? It has to sit at the home dock which has limited clearance at lowest tides (our overweight F32 is fine there), and be able to run and down the ICW for 1-2 month stints aboard with my wife and dog ...

What cruise and max speeds are you getting with the 671's? What fuel economy do you get at 8-12knots, cruise speed and max speed?

Anything else I should know about as we begin looking around? 671 issues, etc?

I see the 8.2 diesel genset is pretty buried - any issues there?

Thank you in advance for any help!

I think the 11 meter is one of the best of the breed.

Her layout below decks has the ten meter beat.

Plus she has the star trek air doors !

Here's the info from Motor Boating and Sailing August 1983

LOA 37' 6"

LWL 32' 1"

beam 14'

draft 3' 3"

displacement 21,000 lbs

fuel 350 gal

water 100 gal

power (std) twin 350 hp gas

price (approx.) 120,000

details

the first full balsa core bottom Trojan ever built

aluminum fuel tank

test boat had twin 450 hp 671 with 24x28 cupped props clocked at 38 mph at 2,500 RPM with tanks 3/4 full and three aboard

If you like, I can scan the article (six pages) and send it via e-mail.

RWS

RWS

I think the 11 meter is one of the best of the breed.

Her layout below decks has the ten meter beat.

Plus she has the star trek air doors !

Here's the info from Motor Boating and Sailing August 1983

LOA 37' 6"

LWL 32' 1"

beam 14'

draft 3' 3"

displacement 21,000 lbs

fuel 350 gal

water 100 gal

power (std) twin 350 hp gas

price (approx.) 120,000

details

the first full balsa core bottom Trojan ever built

aluminum fuel tank

test boat had twin 450 hp 671 with 24x28 cupped props clocked at 38 mph at 2,500 RPM with tanks 3/4 full and three aboard

If you like, I can scan the article (six pages) and send it via e-mail.

RWS

RWS

Nice!

"

RWS wrote: test boat had twin 450 hp 671 with 24x28 cupped props clocked at 38 mph at 2,500 RPM with tanks 3/4 full

3'3" draft will probably fit ... I can't go over about 40' or I can't turn next to my dock to back in (but need some space for the 3 of us for 1-3 month periods.).

I would LOVE to have the article. Thank you for offering!

Its hard to find much on the 11 and 12M convertible. They look nice and are still very wide (low draft).

Any opinions on reliability of the Detroit 671s as compared to my very reliable Cummins 6BTAs?

The 671 is very reliable HOWEVER When they get up in the 450 - 485 hp range ( like the Trojan would have ) your could expect 1500-2000 hour engines between over hauls ( pistons and liners ) they don't break per say but start to smoke .The lower ends last and last. BUT that of course depends on how the are run . Run them easy and it can go longer . Many are in sport fish boats so there run petty hard so that's where the 1500-2000 hours come from . I have a friend that's near 4000 hours on his 485hp 671 but he runs it easy , lot of hull speed cruising . I expect he will get many more hours . The 671 at lower ratings like 200-280 hp is a easy 10,000 + hour engine even run hard .

1500 - 2000 hours is 15 to 20 years for the average boater .

If you get serious about one make sure you get a engine survey by someone that knows these 2 cycle Detroit Diesels . Make sure they are going to pull the air box covers and inspect the pistons and rings and liners , Yes you can see parts of the rings though the liner ports . If they engine surveyor looks at you funny when you talk about pulling the covers and looking at the cylinders ,then you have the wrong guy .

Would I buy a boat with these ? You can bet on it , my next boat very well may have a set .
Good Luck

Thanks RWS and Paul - good info ...

I would never buy a =large boat without a Survey. Hope they ran it easy, but there is always a reason a boat is for sale ...

Will miss the F32 when it goes, but we just need a little more room.

Just remember a boat survey and a engine survey are 2 different things .

There's another interesting thought:

We cruise at hull-speed most of the time.

Hull speed (knots) is 1.34 x Square-root (LWL=Length-Water-Line in feet).

Our F32 has an LWL of about 29', so hull speed is 7.2 knots
The 11Meter (~36.1' LOA) has ~33.1' LWL = 7.7 knots
The 12Meter (~39.4' LOA) has ~36.4' LWL = 8.0 knots

so we pick up about 0.8knots = almost 1mph (+11%) on efficient hull-speed!

prowlersfish wrote: If you get serious about one make sure you get a engine survey by someone that knows these 2 cycle Detroit Diesels . Make sure they are going to pull the air box covers and inspect the pistons and rings and liners , Yes you can see parts of the rings though the liner ports . If they engine surveyor looks at you funny when you talk about pulling the covers and looking at the cylinders ,then you have the wrong guy .

Great tip - anyone have a photo of the rings through the port opening?

Found some pictures of the 671 Pistons, RIngs and Liner through the intake ports with the air box covers removed:

Good job on the Q&A ! good pics Sure cant do that on a Cummins

A little confused on the models.

I see 10, 10.8, 11 and 12 meters in Express, Convertible, Sedan and Motor Yacht.

I assume Sedan and Convertible are the same What I'm interested in).

So, is there truly a 10, 10.8, 11 and 12 meter? Or is the 10.8 actually the 11? (or is the 10.8 the 10?)

Love to get that manual!

Any other 10, 10.8, 11 or 12 meter Sedan/Convetible owners out there?

The 12meter looks like an 11meter with one meter added in the rear cockpit (much like the F32/F36) ...

The 10 and 10.8 are indeed different. The 10 has an LOA of 33
and the 10.8 is LOA of about 36. Three feet added to the stern
I believe.

rossjo wrote:Nice!

"

RWS wrote: test boat had twin 450 hp 671 with 24x28 cupped props clocked at 38 mph at 2,500 RPM with tanks 3/4 full

3'3" draft will probably fit ... I can't go over about 40' or I can't turn next to my dock to back in (but need some space for the 3 of us for 1-3 month periods.).

I would LOVE to have the article. Thank you for offering!

:

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send me a PM with your email and I will scan and send that article

RWS