MARINE conversion?
 

to all,

has anyone here done a diesel conversion for a large boat using an Ford/IH IDI 6.9 or 7.3 NON-turbo engine?

fyi, i've been (for the last 2-3 years) designing a 3 stateroom/2 head 28' x 72' HOUSE-boat to retire to as my principal residence. fyi, the MV DUTCHESS SANALYNN wouldn't "plane" with a GE J-79 jet engine, so all i need is enough power to "displace the water" & get her up to hull speed. = i need at least 108 HP at the marine transmission, according to my calculations.
(fwiw, i don't think that any person could live long enough to explore/fish all the bays, rivers, flats & rivers in south TX & LA, at a speed of about 10 knots or less.)

i would like the houseboat to be diesel-powered, as i'm afraid of gas engines "out on the salt", due to fire hazards.

further, i've found a complete but totaled 1986 Ford F-250 IDI 6.9 (with less than 100K miles) PU near me, for 500.oo. - the engine starts up & sounds FINE!

IF you have actual experience in such a marine conversion & are willing to share your experience, please advise.

THANKS for reading this!

yours, tn46

I don't know for 100% certainty, but I don't believe there are any marine manifolds for those engines, among other parts that would be required for a correct conversion.

Depending on your fabrication abilities and budget, I guess anything could be put anywhere but in my experience you're better off sticking to engines proven in the maritime industry.

Perkins and Yanmar are two brands that are backwards compatible with just about every marine final drive on the market, have parts networks all over the U.S. and world, and will fit into the requirements you have set forth for not a whole lot of money if shopped for keenly.

Mr. Miyagi,

first, THANKS for your reply.

i'm planning to use DRY STACKS with conventional "auto type" mufflers, rather than water-cooled manifolds, as is common with shrimpboats & other "commercial" watercraft on the TX/LA Gulf Coast & a "keel-cooler" & a "homebrew" salt-to-freshwater heat exchanger (made of copper pipe) to cool the water for the engine.

as for your suggestions of a Yanmar or Perkins, neither fit my budget as:
1. those & similar used engines around here seem to be in the 3-5 thousand dollar range
&
2. many of those used diesels, which are within my budget, have significant internal saltwater corrosion.
(until fairly recently, marine diesel engines, around here, ran "raw water" for cooling. - in the last decade "keel coolers" have become common but there are still a LOT of "raw water cooled" engines out there for sale.)

yours, tn46

CUMMINS MARINE > anything else !!!

Okay, understood...up here in the NW boat engines and parts are all over the place....the colder water helps keep major internal corrosion at bay--seems like stuff lasts longer up here in the water than it does in the 'Gulf.

if you plan on dry exhaust and the homebrew keel cooling, it would probably work, depending on the final drive setup you plan on using.

Biggest thing is, as you are well aware, a boat engine is running at 100% load most of the time, so having robust longevity is important, unless you don't mind frequent engine-out services.

The old school NA IDI Navistars had head gasket issues when pushed hard...mostly stretched head bolts, but at any rate a high quality replacement gasket with new bolts torqued under the new Navistar/FoMoCo procedures would be recommended.

If you shop around, a used-but-not-abused Cummins 6BT or BTA from a 1st or 2nd gen Dodge truck, or other applications, can be had for $1,500, or even much less....I think that would be a better place to start. They convert easily into the marine package, whereas the one-off Navistar might prove to be a headache, unless you're planning on like a C6 transmission to 20 degree straight shaft final like some drag boats used to do--with a Powerglide, but same principles.

The Navistar/Ford idea is unique though, and I like unique. :c:

Mr Miyagi et. al.,

the MAIN reasons for my interest in converting the Ford IDI are:
1. my experience with the 7.3L IDI in my truck & the FACT that i've never had a minute of trouble out of it NOR have any of my friends who drive the early IDI engines had any "exotic problems" with theirs,
2. i'm SHORT of $$$$$$, being retired on a small pension,
3. i know how to work on the "old school cornbinders",
4. i know ZILCH about working with/on Cummins engines
and
5. the 82,ooo mile wrecked Ford PU is NEARBY & (now!) just 400.oo!

to ALL: has ANYONE actually tackled such a IDI project?

i'd sooner NOT be a "pioneer", as the bones of "pioneers" litter the desert. (CHUCKLE!)

yours, tn46

You won't be a pioneer in the sense, but you will be going down a road that has been tried before and didn't work out.

Mercruiser offered the 7.3 diesel in one of their option packages years ago, as did a company called Starpower Diesel.

There may have been a Yanmar badged 7.3 as well but my memory is fuzzy on it.

They didn't sell well, and didn't work out well, although I don't recall the grisly details on the whole affair.


The general opinions from those in the industry will be to stay away from the 7.3 in a boat, for a wide variety of reasons. Your mileage may vary, but it is what it is.

I did a Yanmar refit a couple years ago to a boat originally equipped with a gas engine. The majority of the cost was not the engine, but all the peripherals....granted my application of use is not the same as yours will be.


You can search at boatdiesel.com or thehulltruth.com to see if someone has done this before....I love the 7.3s in my Fords but don't think I'd like them in a boat. YMMV.

Mr Miyagi,

once more, THANKS for your response. - i'll check out those sites, too.

yours, tn46

I've thought about diesel boats too mostly in speed boats and fuckaround boats(Those speedboat cruiser things with the galley, bathroom and small hull sleeping area). I stile think a multi speed transmission could benefit a boat especially a transmission with mostly gear induction.

You're welcome, TN46...best of luck, it sounds like you've got a pretty cool project regardless!
:c:

the main thing i've found about a 6.9 blowing a head gasket is the motor getting really hot. If you can figure the cooling out you should be ok. p.s. KEEP the RPM's as low as possible.

It can be done and would probably work very good
 

I have my motor already as we speak in the garage. I am sooo tired of everyone opinionating without any facts !! Mercruiser did make the 7.3 in marine trim now why it didnt fly god only knows, I ve never heard a single person that owned one speak up. They are incredible engines on the ground, so they have to wotk in the water as well. I know of one trawl boat in louisiana that has had a 6.9 converted for 20 years, I guess it isnt proven yet. If the parts werent so outrageous I would be done with mine already, but its hard being that mer Screwser wants $1900 for a marine starter alone !!! Gooduck sir.

6.9 is a great engine. they're higher compression and i have blown a headgasket. i no longer have a 6.9 in but i walk by the engine every day working on my truck and there's still somethin special about it to me. If thats what you want i'd say go with it, it's a great engine

Desygityaso,

FYI, you need NOT use a "marine starter" UNLESS your engine is "buried in the bilge" OR tightly enclosed. = NOBODY, that i've known over the last 3+ decades, on the "commercial waterfront" uses "special marine parts" for "OPEN installations", assuming that "regular parts" are available for the same/less $$$$$.


thanks for your input.

yours, tn46

---AutoMerged DoublePost---

to ALL:

as i've now received a couple of "off forum" questions on this subject, let me give you a few bits of information:
1. it takes LITTLE HP to keep a "full displacement hull" at or below "hull speed", as these hulls (once moving) have a great amount of inertia & will just "ghost along".
2. it takes MUCH more power to get the hull to "hull speed".
3. "hull speed" is calculated as the square root of the "immersed waterline length" times a constant of 1.34. = in the case of the MV DUTCHESS SANALYNN, this is about 10.1 knots per hour. furthermore, her "cruising speed" should be about 7KPH, with the engine idling at least 75% of the time, making little or NO "wake" to disturb her surroundings.

as some here have doubtless guessed, i know "one H of a lot more" about hull design & construction than i do about POWERING any hull!

yours, tn46

I SAY...

Stud it... and give it a try... for 400$ i don't think you will ever be raped in the a**

however... i say the Cummins 5.9 6BT with a P7100 pump will be the most reliable.. !!

angelicO-,

in case you didn't notice, i'm SHORT of $$$$$$ & CANNOT afford a Cummins. = around here, good/used 12V Cummins engines sell for at least $2K, which is at least 1600USD more than the whole wrecked PU that i've found.
(yep, i'll strip it for re-sellable parts & recover at least a few $$$.- hopefully, ALL of my investment!)

the ONLY way that i can afford the project (at all) is by doing most of the work myself (with some help from family & friends), "scrounging" everything possible, recycling used lumber/fixtures/flooring & doing the houseboat "on the cheap". ======> my GUESS is that the boat will cost about 5-8,000USD to build.

yours, tn46

texas ..just read your post from june 2011 about the 6.9. if its not too late I have info about the marinized 6.9 ford (International) I have one in my 38.

digr97,

THANKS for your post. IF you are willing send me a PM telling me all about your marineized 6.9

thanks, tn46

Ive been trying to add a pic on this site,,,,its driving me nuts..not an expert with puters ,so if possible can I send it using email address...my address is geobasha@gmail.com.
let me know tn46.
george

digr97,

SADLY, i still have NOT received the pictures to my email, either.

yours, tn
texasnative46@gmail.com

---AutoMerged DoublePost---

digr97, et.al.,

FYI, i just found/bought a 1985 gray in/out NON-turbo 300D M-B sedan with ALL manual windows/sunroof AND a factory-installed Getrag FIVE-speed stickshift, with 246KM on the clock. = It was special ordered through the Canadian PX by an American LTC of the USAF & "privately imported" in 2001.
(When he imported the sedan, he KEPT the NON-US headlights/taillights/bumpers/etc & i'm getting those too.)

strangely enough, when i rotated to CONUS i wasn't allowed to bring my red M-B coupe back! = !@#$%^!

yours, satx

did this project ever happen? i have a 6.9 in my van and i am wondering if i can marinize it and put it in my houseboat. would be interested to know the end of this story?

marine engine 6.5 chevy
 

[QUOTE=texasnative46;768823]to all,

has anyone here done a diesel conversion for a large boat using an Ford/IH IDI 6.9 or 7.3 NON-turbo engine?

fyi, i've been (for the last 2-3 years) designing a 3 stateroom/2 head 28' x 72' HOUSE-boat to retire to as my principal residence. fyi, the MV DUTCHESS SANALYNN wouldn't "plane" with a GE J-79 jet engine, so all i need is enough power to "displace the water" & get her up to hull speed. = i need at least 108 HP at the marine transmission, according to my calculations.
(fwiw, i don't think that any person could live long enough to explore/fish all the bays, rivers, flats & rivers in south TX & LA, at a speed of about 10 knots or less.)

i would like the houseboat to be diesel-powered, as i'm afraid of gas engines "out on the salt", due to fire hazards.

further, i've found a complete but totaled 1986 Ford F-250 IDI 6.9 (with less than 100K miles) PU near me, for 500.oo. - the engine starts up & sounds FINE!

IF you have actual experience in such a marine conversion & are willing to share your experience, please advise.

Hi cheapest way is a chevy 6.5l with hurth transmission
can send you correct numbers if you like
you can get 170hp natural asperated out off one but very good torque
I have two in my boat check my post out
with you tube link to engine running top off this post
My engines only use 1ltr an hour each on tick over boat does 6 knots hope this helps you stay away from common rail electronics
go mechanical injector pump for salt use no hassle cheap to repair more reliable as software upgrades do not go while at sea

Kind regards carl

exhausts chevy 6.5 l
 

Hi
I can sell you a kit off proper exhausts for the 6.2/ 6.5 l engine
Full aluminium manifold with stainless risers just newly modified the water jacket in manifold comes out of the top of manifold
not in it ! Then salt water goes into riser there preventing the engine ever hydraulic locking

If you would like some can supply you a set
Kind regards carl