Lighter vs heavier diesel engine

[Kasper]

I am repowering my sailboat, and have therefore read up on a large number of engines from known manufacturers.

While most modern diesel engines are similar, I have noticed some significant differences in weight (with gearbox). For instance, the Volvo Penta D1-20 weighs 131kg, the Yanmar 3YM20 weighs 130kg. On the other end of the scale we have the Beta 20 weighing 104kg, and the Lombardini LDW702M weighing only 99kg!

What is the cause for these rather significant differences, and does the weight impact durability, vibration, sound or other factors?

[skipperpete]

Originally Posted by Kasper

I am repowering my sailboat, and have therefore read up on a large number of engines from known manufacturers.



While most modern diesel engines are similar, I have noticed some significant differences in weight (with gearbox). For instance, the Volvo Penta D1-20 weighs 131kg, the Yanmar 3YM20 weighs 130kg. On the other end of the scale we have the Beta 20 weighing 104kg, and the Lombardini LDW702M weighing only 99kg!



What is the cause for these rather significant differences, and does the weight impact durability, vibration, sound or other factors?

Avoid the Lombardini . I like the 3YM30, but the D1-20 is a very good and reliable engine too, however Volvo didn’t do a great job with the marinisation. Better than the 2030 and 2020 but still not up to the Yanmar standard. Yanmar built the entire engine and cooling system, VP simply marinised a Perkins/ Shibaura industrial engine.

[Kasper]

Originally Posted by skipperpete

Avoid the Lombardini . I like the 3YM30, but the D1-20 is a very good and reliable engine, but Volvo didn’t do a great job with the marinisation. Better than the 2030 and 2020 but still not up to the Yanmar standard, they built the entire engine and cooling system, VP simply marinised a Shibaura industrial engine

Hi,

What about the Beta? Why are they so light compared to the bigger brands?

[Uncle Bob]

Originally Posted by Kasper

I am repowering my sailboat, and have therefore read up on a large number of engines from known manufacturers.

While most modern diesel engines are similar, I have noticed some significant differences in weight (with gearbox). For instance, the Volvo Penta D1-20 weighs 131kg, the Yanmar 3YM20 weighs 130kg. On the other end of the scale we have the Beta 20 weighing 104kg, and the Lombardini LDW702M weighing only 99kg!

What is the cause for these rather significant differences, and does the weight impact durability, vibration, sound or other factors?

So you are worrying about 30 kg, may I suggest that you may be better off basing your decision on the engine performance, parts availability and reviews of others that have made a purchase. 30 kg in reality is nothing.

[Kasper]

Originally Posted by Uncle Bob

So you are worrying about 30 kg, may I suggest that you may be better off basing your decision on the engine performance, parts availability and reviews of others that have made a purchase. 30 kg in reality is nothing.

Hi, thanks for the response.

Not too worried about the 30kg in terms of weighing down my boat. However, I am more curious towards why the weight difference (30% increase from Beta to VP) is there. And how this might affect things like noise, vibration, durability etc. Does the VP have something that the Beta does not for instance?

[Uncle Bob]

Originally Posted by Kasper

Hi, thanks for the response.

Not too worried about the 30kg in terms of weighing down my boat. However, I am more curious towards why the weight difference (30% increase from Beta to VP) is there. And how this might affect things like noise, vibration, durability etc. Does the VP have something that the Beta does not for instance?

Judging from two neighbouring boats the VP has exponentially higher parts costs with limited availability, both have switched to beta and nani ( both Kubota based) and are happy with their decisions.

[deblen]

My opinions Volvo,Yanmar,Beta/Nanni-all basically good engines.
Your choice should be influenced quite strongly by:


1.Parts & service in your area.
2.Other owner's reviews of the service shop.
3.Source/price of parts. eg. Volvo,Yanmar-usually available from OE mfgr & expensive.Beta/Nanni-based on common Kubota engine used by many tractors & other non-marine so parts can be much less expensive.
4.Installation complexity/cost. eg.How much modification $$ to fit new engine in old boat?


Cheers/Len

[Tortuga's Lie]

I would also like to add that you should make your choice not only on parts availability but on ease of access for replacing those parts and regular maintenance, especially for your particular setup. For instance, I have an older Yanmar(3JH2-TBE) that has been great in the 8 years I have owned it but the accessibility to change out the impeller is awful, the engineers who designed this engine should be made to suffer! I have to drop the alternator to be able to reach the cover plate to the impeller, as this is facing aft not forward. Even if I had a better side panel to the engine compartment, it wouldn't make that much of a difference. So, ease of maintenance is key!

[boatpoker]

One more thing to consider ... we needed a new engine last September , Yanmar wouldn't give us a delivery date and Beta told us May !

We found a three year old Beta on Facebook that had never been out of it's crate and is now running great.

[NorthCoastJoe]

The Beta basic engine is a tractor engine parts are easy to get and costs less. Even in the San Francisco area some Yanmar parts need to be ordered, where Beta is off the shelf ready. As for weight good question?

[Brioche]

I have a Beta-14 and am happy with it. I do not notice any significant vibration compared to that on other diesel-powered boats, most of those, admittedly, bigger or a lot bigger. I also do not use it much -- mainly getting in and out of the marina in no-wake zones, but occasionally heading into strong winds. Very happy with ease of service and quiet operation.

[Kd9truck]

Hey Kasper, I would like to ask, are all the motors and the corresponding mounts all compatible with you vessels motor support system? I have a friend in the yard my vessel is in who bought a created motor that needs major modifications to the sleepers to accommodate the motor.

Cheers

[Sailorichiban]

Hello All,
In the New York area Yanmar parts are sometimes annoying to obtain.

Yanmar I believe has a multilayered distribution system, meaning multiple price increasing companies and individuals incorporated into the supply chain.
Based on personal experience delivery time can be increased by months as the parts are shifted through the supply chains.

My solution?
Dealt with a sub company of Yanmar ( owned by Yanmar) with a warehouse and engineering staff location in Kentucky. Actually contracted the president of the sub company in japan and he instructed his staff to assist us. This was only possible due to my Japanese connections.

Likely every brand has its own pros and cons.
The best place to operate a Yanmar is Japan!

I would still prefer to have a Yanmar.

[Rumpi]

Originally Posted by Kasper

I am repowering my sailboat, and have therefore read up on a large number of engines from known manufacturers.

While most modern diesel engines are similar, I have noticed some significant differences in weight (with gearbox). For instance, the Volvo Penta D1-20 weighs 131kg, the Yanmar 3YM20 weighs 130kg. On the other end of the scale we have the Beta 20 weighing 104kg, and the Lombardini LDW702M weighing only 99kg!

What is the cause for these rather significant differences, and does the weight impact durability, vibration, sound or other factors?

Go back and read again, this time more carefully, so you can compare apples to apples. For example the Lombardini is a 2 cylinder engine and all others are 3 cylinder ones.
The 3YM20 dry weight without gearbox is 110kg. The recommended Kanzaki is only 9.8kg.
The Volvo D1-20 is only quoted with gearbox (132kg) or saildrive (144kg).
The Nanni 3.21, is quoted 106kg with gearbox (TMC 40, 8.8kg).
The Beta 20 is quoted 104kg and it doesn't actually say if it's with or without gearbox. It's the same base engine as the Nanni.

If you want to know where the weight differences come from, you need to compare the base engine weight vs. the marinized version, and the different gearbox/saildrive weights. For example the Kubota D722 wich is the basis for N 3.21 and B 20, weighs 63kg naked. The Perkins 403D-07 wich is the basis for the Volvo is quoted 71kg, but Perkins does not weigh the same things as Kubota so you can't compare them unless you know the difference.

In short, the variation isn't as much as you think and comes mostly from the marinisation parts.
The Lombardini is indeed lighter because besides all Al construction it also has unit injectors and belt distribution.

[Kasper]

Originally Posted by Kd9truck

Hey Kasper, I would like to ask, are all the motors and the corresponding mounts all compatible with you vessels motor support system? I have a friend in the yard my vessel is in who bought a created motor that needs major modifications to the sleepers to accommodate the motor.

Cheers

Hi,

There are differences in the width between the engine mounts, and some would require modification of the engine bed (My current is made for Volvo Penta 410mm width). I might underestimate the amount of work changing the width of the beds, not sure.

But I am looking to purchase a used engine, and therefore would like to see what the main differences are as different engines come out for sale from time to time.