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