Hi
Got my self a 26 feet boat this year (Mod 1983), with a 1983 OM617 (Non-turbo) 88bhp engine. I believe the engine been in the boat since new, it looks well, run perfect and there is no oil consumtion. The max RPM i get is close to 3600 rpm, but not 3600. Normally I cruise at 3000rpm, which gives 10 knots, the 3600 gives 14 knots. (No speedboat).
Now the question for you merc and diesel experts, would the 617 manage under more power? Let say I tweaked with the full load adjustment so it managed 85% of max rev so that I could make it run 3800 rpm for let say 2 houers period? I do know tweaking will stress the engine a bit more, but this robust engine running at 85% of max RPM would probebly manage. (The boat it self are classed for up to 144bhp)
Or perhaps, a non turbo 617 do not "eat" more fuel so that it will not get any out of a full load adjustment.

You would need to adjust the main governor spring, that will increase RPM. The engine will be fine running at 4000rpm, but in the cars it isn't doing that at full power.

Do you have a tachometer? These engines turn a lot faster than they sound.

How about getting a lower ratio??

Hi.

When not in gear, there is no problem running the engine up to 4000 or more. I got a tachometer, and yes they sound running faster then actually. 6 years ago I had a Korean car with a OM602 engine (2.9 litre), so a bit familiar with the 5 cyl. I did increase power out of it with adjusting the full load screw. (It had a STT aftermarked turbo, and stock 120 BHP. Managed approx 143 bhp after adjusting the full load screw.)

Well, back to the 617. Adjusting the main governor spring will perhaps help, but what if the limit of rpm is due to lack of power, not limitation from overrun? Does the adjustment of the main governor spring do so it allow running faster before decrease of fuel to limit overrun rpm? If so, this will perhaps help.
And, how much power can you tweak out of a 617 non turbo, 10% more then the stock 88 bhp?

Change of ratio will cost more, as will need either new gearbox or prop.
The cheapest tweak for more speed for me is to allow this robust 617 engine run faster.

And finally, any link to were to buy a back cover gasket for the pump, as I believe I need a new one if I open it.

(08-06-2010 03:52 AM)mussonor Wrote:  When not in gear, there is no problem running the engine up to 4000 or more.

Based on that it sounds like power is your limit right now. As Actros617 suggested, a lower ratio is what you'd need. A turbo with 5psi of boost and 1/2turn on the full load screw would help too.

Red line is 4800rpm depending on years but max power/TQ is at 2800rpm

just from feeling the power increase of my friend's 617 n/a was 15-20%.
He did > 1000 km now with the "new" pump and average consumption went down by > 10% (although he used the more power all the time).
It is proven that also a non turbo profits from larger elements regarding power and economy.
Put in such a pump and also fit a bigger prop then run it at cruise speed of 2000/min and enjoy.

It could be wrong to install a turbo engine in a boat that should cruise at low revs because of the "single gear" you might not get enough boost to get off the water. Once out you have to take back throttle but then you only use a small part of the potential of the engine. We face this with a 3.6 to boat and a 605 turbo engine with estimated 220 - 230 hp. Still some issues, but with stock IP and ~ GT25 wastegate turbo the beast did not make it out of the water (did not build boost more than 0.4 bar). It felt like climbing a hill under full throttle without shifting back from a high gear.
In about 2-3 weeks we expect a test run.

Tom

Thanks a lot for input.

I believe I will try to make one half turn on the full load and see what it can manage, would be very pleased if it could go 4000 rpm.
I made a rpm/speed plot, and a "conservative" trend for speed above 3600rpm point at a speed above 16 knots.



Many thanks,
Mussonor

To day I tried the fuel tweak. I opened the back of the pump, very narrow space doing this. Had preped with the propper tools.

Made on full turn of the 13mm screw.

Made a test run. The engine seemed to be more responsive, but flatted out at 3500 rpm.

So, perhaps the limits is the rpm, and I should made an adjustment on that screw?.

Is it cw or ccw that will increase rpm, and how much should I turn it?

Propper tools, and this is how the pump looked like:
[attachment=3395]    

Just in after a trip with the boat for fishing.
Haven't done anything more on the pump since adjusted the full load.

I made full throttle, and RPM flatted out at 3500 as usual. This is first time in a long time that there is no wind while out with the boat, and now looking back I noticed that I gave black smoke. Earlier It have not made any noticable black smoke under no wind conditions from the exhaust at full throttle.
So, conclution must be that there is no more power to gain out of it without more boost. More fuel made it just to smoke.

Second conclution, I just will have to live with it like that.

Is there not enough room to put a turboed 617 in? The added weight is nominal.

read post#7 again...

Tom

(08-22-2010 01:19 PM)tomnik Wrote:  read post#7 again...

Tom

That could be overcome by a smaller turbo, vnt/vgt or gearing. I am suprised it doesnt have an om314...

I agree. No reason a turbo will not work in a boat.

http://www.youtube.com/watch?v=h7O9a9KBKfk

the boats are different.
The engine is n/a and the easiest way to get some revs more is to exchange the IP to larger elements.
The turbo lag might not enable the boat to get on the water.
In the video the boat is on the water already without (much) boost so rev climbs fast with boost.

Tom

(08-23-2010 05:49 PM)ForcedInduction Wrote:  I agree. No reason a turbo will not work in a boat.

http://www.youtube.com/watch?v=h7O9a9KBKfk

I like this video but that motor is stout and has a lot of power to begin with. That is a Nissan V8 not sure on which one but it even in the smallest cubes makes more power than a 617 and is multi overhead cam . I am actually building a outboard turbo so have done some huge research on turbos and boats. A boat is always climbing a big hill so torque is the key to get the boat running better. Put a smaller than normal turbo on it so it builds boost fast and it will run real nice.

(08-24-2010 12:30 AM)95e300dez Wrote:  Put a smaller than normal turbo on it so it builds boost fast and it will run real nice.

Don't say that, you'll piss off The Tuning Gods!

@ mussonor:

in about 3 weeks from now I will have "my own" 5 cyl. M pump with 7.5mm Floyd elements available.
If you want I can install it on my friend's n/a 617 and roughly adjust the max. delivery, take it out and send it to you for testing (you have to pay shipping). In case you are not satisfied I'll pay for shipping the IP back to me. Further options are to send it back on your cost or to keep it and pay for it (please note that I don't want your blue IP in exchange).

Tom

(08-26-2010 09:10 AM)tomnik Wrote:  @ mussonor:

in about 3 weeks from now I will have "my own" 5 cyl. M pump with 7.5mm Floyd elements available.
If you want I can install it on my friend's n/a 617 and roughly adjust the max. delivery, take it out and send it to you for testing (you have to pay shipping). In case you are not satisfied I'll pay for shipping the IP back to me. Further options are to send it back on your cost or to keep it and pay for it (please note that I don't want your blue IP in exchange).

Tom

Thanks for the offer, but there is just 4 weeks left of the boat season here now, I'll take the boat up for the winter in 4.-5 weeks time.
Next year will be the next time I willl take a look into this.
Untill then, many thanks for all the inputs.

here is a dyno chart of a 617 NA.
Only mod is a M 5 IP with larger elements.
(4 speed manual, 3.47 rear end).

Tom