Cummins vs Yanmar

[alex fletcher]

Just notice this "Yanmah LP6 the same as Toyota"? yes but no yes the LP6 is produced by the same moulds That Yanmar got from toyota. but Yanmah Added a Ladder Frame Crankshaft Base, Crown cooled Pistons, waste gate turbo, inter cooler and stuck with a mechanical injection pump it is a efficient and reliable system that work well a go option in my books an other option would be a small MAN high Speed Diesel.

[catmando2]

Hi guys, don't know a huge amount about diesels, but i have fitted cummins to the cat i'm building.They are only 65hp ones though. At the time I got them Yanmars comparitive was 2 litre and spun arond 3600rpm, Isuzu was about the same but the cummins was a whopping 3.3 litre and reved at 2600rpm. we reckon we'd only need 50hp most of the time which is around1500 rpm from memory. Also had plenty of reports of how indestructable these little/big motors are which made me feel a bit better. Change in U.S.dollar vs Aussie dollar helped in the decision a bit as well. the ones we got have no electronics or turbo, sounds great to a ludite like me.
Interesting to see the new Yanmars are slow spinners now,so I believe.

Dave

[brian eiland]

December 2005
YANMAR AND BMW ENGINE SUPPLY AGREEMENT
YANMAR CO LTD and BMW AG, German manufacturer of luxury vehicles, have agreed that BMW will supply four and six cylinder Diesel engines designed for high performance use to YANMAR MARINE INTERNATIONAL BV as the base engine for the new YANMAR MARINE product line.

This agreement enables YANMAR to have the most advanced marine engines for its product range. Customers will be in the position to benefit from the joint efforts of two of the most reputable companies in their respective fields of operation with a product that will set new standards in the Marine industry.

YANMAR is aiming to introduce this new fully electronic range of Premium Marine Diesel Engines in the market around mid-2006.

...more at http://boatdesign.net/forums/showpost.php?p=75304&postcount=138

....and even more auto engine marinization at
http://boatdesign.net/forums/showthread.php?t=650

[brian eiland]

Noted a fair amount of Steyr discussion here, so I thought I would reference this:

Steyr Integrated Flywheel Generator (IFG)

Here's an interesting new innovation from Steyr motors, an onboard AC generator located inside the engine's bellhousing. Another technology arising from the new 'permanent magnet' technology applications.

...couple of photos here http://www.yachtforums.com/forums/32761-post63.html

[ABoatGuy]

The Cummins QSB5.9 is a common rail engine, the Yanmar is not. If the common rail technology is exploited the fuel can be introduced into the cylinder in multiple shots on each stroke. This eliminates the typical deisel rattle on each stroke. They sound more like gas engines.

Having installed both, I would go with the Cummins if your biggest criteria is noise. Naturally a good silencer etc. goes a long way toward any engines noise.

Which ever you pick, choose your gear ratio carefully. Watch the torque at the prop and choose the ratio accordingly.

The new Yanmar 6SY is a Steyr engine, the 6LY is not.

[FAST FRED]

The RV folks seem to be very happy with the new GM Duramax diesels.

If you think a boat is always going "up hill," you have to drive an RV , where some throttle is required to maintain speed DOWNHILL!

Anyone marinizing these yet? Onlt 850 lbs for claimed 300hp.

FAST FRED

[zzmeyer]

Yanmar. As my mechanic said "You take care of a Yanmar like you do a hard on. Don't f**k with it."

[Frosty]

zzmeyer,---Change your mechanic to one that knows what he is doing.

[zzmeyer]

I'll pass the good word along to him. I think what he was saying is that with good normal maintenance, which he does every 50 hours, these engines last a long time. I've only had it for 12 years without a problem so I'll have to wait a while and see.

[Frosty]

Which Yanmar are we talking about?

[Ari]

Originally Posted by jack frost

Which Yanmar are we talking about?

Must be the older single,twin our triple cylinder.They do last very long..eventhough I did not understand what that mechanic means..my perception is 'do not modify the engine, keep it in original as per design'. It is normal to have the slow revving small horses Yanmar engine last that long.. They are slow..and their aging also very slow..!

[zzmeyer]

4JH. My mechanic has said "the boat is yours, but the engine is mine". Keep the engine clean, check the fluids and filters, keep your batteries new and call me every 50 hours. We are religious in maintaining the engine. We replace on schedule, not when something breaks. My engine is clean enough to have a dinner party on and I might not be afraid to eat food I drop on the engine pan - a good place to look if you are having problems like oil or salt water leaks.

[Dutchy]

Only the 6LP engine has a Toyota block as base engine.

[Frosty]

6LP and the 6LA Are all Toyota --heads as well.

Thats the 2 valve head and the 300hp 4 valve head. Toyota.

[FAST FRED]

6LP and the 6LA Are all Toyota --heads as well.


I understand the marinization also includes beef up like a crank girdle etc.

Just yanked from a car , and unmodified could it be used as a 200 hp engine , with 160hp taken out 5 hours a day as a max?

The Cummins 5.9 is really easy to find in US junk yards , but the engines are louder mechanically than any other engine UGH !! so I worry that any saving in engine cost would be offset with hundreds of pounds of expensive noise control products.

The new Electric ones are "better" , but how many control boxes would be needed to cruise in the "Florida, Lightning Capital" of the world is unknown.

FF