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Discussion Starter #1
just an update to the forum.. have bot of my 617.951 turbodiesels running in my boat project.. attached to the marine transmissions and almost ready for a sea test..

anyway, lots of photos and a few video clips fo the engines running in the boat.. and a nice exhaust note thru the marine exhaust..

check it out:

http://www.coastalboatsales.com/jfraley/gallery/
 

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Great pics! I've been wondering how this project was going....
 

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Is there any news on this?
 

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Discussion Starter #5
snap clink crunch

well the first sea-test was pretty sucessfull, discovered a few leaks and solved a couple other problems.. but that test never really got much above idle, anyhow today (sunday) it went back into the water for a range of other tests and everything was flawless until I had her wide open and was just starting to come up onto plane and the stbd side motor broke the timing chain...crunch... game over for now.. but the nice thing about having two engines is the other one will get you home.. and it did just perfectly..

I think I have everything dialed in now.. just need to pop that motor out and drop in the spare engine, and rebuild the now broken one.. the now broken engine was donated from a 123 car that was hit pretty hard in the front, hard enough that the radiator support came back and hit the very top of the valve cover knocking a small hole in it, I carefully examined the chain and cam sprocket and ran a dial indicator on the cam sprocket to chack for a bent sprocket and everything looked fine, but I guess the crash imapct damaged it somewhere that I could not see. I probably ran the engine for about 4-5 hours before the chain broke but I had not put that much stress on the engine before. I will be putting the spare engine in and see what happens next..

dont have any performance numbers for you guys yet.. that was going to be the first attempt at top speed, she sure sounded good though.. pushing those throttles forward and the sound of a pair 617.951's turning up and the turbos spooling .. I think she will do pretty good when I get her back together

so .. everyone.. lesson here? go check your timing chain stretch and replace if nessesary, you do not want to hear the sound I heard today.. its not plesant ..

more updates (and photos) later..

-Jason
 

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Ouch! Quite a setback, but it sounds as though it was one you were prepared for. I am eager to hear of the next test.
 

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Discussion Starter #7
well I updated the photo site with the photos from the first sea trial.. which is old news now.. the second sea-trial is when I broke the timing chain... but anyway some cool photos, and a short vid clip..

stay tuned.... more to come
 

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Discussion Starter #8
just an update to the forum:

have broken-chain engine out and the replacement engine sitting next to it
with overhaul complete, just need to switch components over to the good engine and re-install. I am also changing the vibration dampeners, to a different setup which is going to require a bellhousing and flywheel mods to make it fit..

have not worked on it in a while.. and I am just now getting some time, I will really try to get the updated photos on the website on monday.
 

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Bump. :roll:
 

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Discussion Starter #11
some updates to the photo archive

I have made a few updates to the website: paintwork, before sea-trail #2 shots
and some photos of the new vibration dampener and the fit problem I am encountering.

I actually have the machine work done on the flywheel adapter, and a test fit of components last night revealed I am now only 5/32" away from a fit at this point.. not bad from the 1/2"
I had before. So its back to the lathe and mill to chamfer some edges to try and find 5/32" of clearance somewhere.

anyway check it out for those interested:

http://www.coastalboatsales.com/jfraley/gallery/scubaboo/

-Jason
 

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Thanks for the update!
 

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Has there been any news on this project lately?
 

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Discussion Starter #14
nothing on the MB diesel front..

recap:
I broke the timing chain on the stbd engine second time out..
have pulled that engine, and went thru a spare engine and replaced timing chain, seals, gaskets, tensioners, etc. That engine is reattched to the marine transmission and ready to lift into the boat. I am currently working on finishing up the prep-work for painting the topsides and cockpit decks, when the prep-work is finished, and it is painted, I will re-assemble the gantry hoist around the boat and lift in the replacement engine.
then I will complete the electrical system, and its back into the water.
 

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First off, I gotta say, great job on the boat, you are doing an amazing job, can't wait to see it done (and I live in Tampa, so i can *really* come see it when it's done!!)

Anyway, I just picked up a 300SD to drive, but before snagging that I was looking into cramming a MB diesel into a Jeep (still gonna do that)

One of the guys I've been discussing this with (not an MB guy, but a diesel guy in general) said that from what he had found online, that engine has its balancing parts in the automatic tranny. Since you've got rid of the slushbox, how is vibration? Could that be something I wouldn't need to worry about?

Thanks!

-brian
 

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Discussion Starter #16
balance

I am not aware of any balancing done in the transmission (outside of its rotational parts are balanced).
the engine itself is balanced, and the flywheel is balanced as a stand-alone unit.

I am fairly certian that the entinr thing is NOT balanced as a unit..
that goes against everything that I know that is german

anyway I have run my engines without anything connected to either end of the crankshaft
including without the harmonic dampner on the front they still run very smooth
( well, as smooth as you could expect from a 5 cyl diesel ! )

additionaly in the automatic trans, the tourqe converter will soak up alot of torsional vibrations. in my marine environment I use a torsional vibration coupler in-between the engine and the marine transmission.
 

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Discussion Starter #18
flywheel

you just have to look carefully at the flywheel.

if you use the MB automatic ring gear how do you plan to connect to the input shaft of the
manual trans ?

you will need a bunch more rotating mass in the form of a heavy flywheel, or you will burn up your clutch trying to modulate the throttle on standing starts.

I would come up with a way to bolt the flywheel from the manual trans to the MB ring gear
( and possibly machine it extensivley to make this happen.

if you look at the flywheel for a manual shift MB transmission for the same engine
its about 40 lbs. vs the automatic flywheel/ring gear at about 10-12 lbs
 

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Re: flywheel

jfraley said:
you just have to look carefully at the flywheel.
I will keep that in mind, thanks!

if you use the MB automatic ring gear how do you plan to connect to the input shaft of the
manual trans ?
I have absolutely no idea how I'm going to do it. I won't be getting another wrangler until later this year. We'll find out then. ;)

if you look at the flywheel for a manual shift MB transmission for the same engine
its about 40 lbs. vs the automatic flywheel/ring gear at about 10-12 lbs
That's good to know.

Thanks!

Now I have to convince you to let me come over to your house and let me pick your brain on tuning up (beyond valves) my engine. ;)

-brian
 
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