BETA 20 vs Yanmar 3YM20

[picardy]

I am sorry if this is a well trodden question but couldn't see anything in the search function.

I am ordering a new engine to go in my new wooden 20ft launch which I am having built. Simple question is which engine is the quietest, smoothest running and most reliable since they both have 3 cylinders and are almost identical HP.

Upfront cost, parts and servicing costs is not a big influence on my decision whereas the other 3 are very important to me. Both seem to have good reputations but there is little info available on noise, smooth running and reliability.

Many thanks

 

[fredrussell]

As an armchair expert I would say I doubt there’s much between them. They’re both modern 3 cylinder boat engines from proven manufacturers (Kubota & Yanmar I mean) and what you’re likely to get is those folks with one type singing it’s praises, and those folks with the other type also singing that one’s praises. You probably should try and arrange to see boats with these engines in (when restrictions ease) and have a gander.

 

[Kwik Decision]

We re-engined our previous boat with a Beta 25, and our current boat has a Yanmar 3YM30, so both 3 cylinder, although the Yanmar is a little larger capacity. Both smooth running, both make a lot of noise with the engine cover off, so good sound insulation will be needed whatever you chose, both were / are maintained carefully, and have been 100% reliable (although the new owner of the previous boat, with the Beta, did need a new seawater pump (Jabsco?) at around 5 yrs old).
Worth considering the location of the service parts on each engine, with respect to where it will be located on your boat, and hence access to them. If this doesn't sway the decision, then Beta are very good to deal with, a little cheaper to buy than Yanmar, and the spares are cheaper...

 

[Tranona]

A bit like what colour is your upholstery or do you want a Golf or a Focus. Would also consider a Volvo D1 20, either to add complication or another colour. Difficult to tell them apart on noise as much of this depends on the installation, particularly the sound proofing of the engine box, although personally I find Yanmars "pitch" a bit higher than others. As for smoothness, again depends on the installation but they are all basically the same. Reliability is a function of maintenance as again there is little to choose on the basics.

Yanmar and Volvo have the large scale production market sown up, whereas Beta (plus Nanni and Vetus) have concentrated on the replacement and small builder market offering more customisation and personal service, plus lower prices.

Long winded way of saying you really can't go wrong.

 

[LittleSister]

I'm not in a position to compare, but my Beta (14hp twin, newish but not installed by me) was very satisfactory and reliable, and I was most impressed by how how good Beta were at providing advice, spares etc. You can ring up, talk to someone who knows what they're talking about, and will despatch spares the same day.

 

[jwfrary]

Personally I would go for a yanmar. Slightly quieter I think but honestly probably hard to tell.

I expect more important for sound reduction would be reducing the structural born noise via a decent coupling (centaflex m127) careful routing of hoses and exhaust. And generously provisioned sound insulation.

if you really want things quiet have you considered electric? Maybe investigating lynch motors might be worth while.

 

[neilf39]

As has been said, check where the ancillary components are compared to your engine access. Both engines are fine but we went with a Beta as I could get to everything slightly more easily as I only have reasonable top and front access. Also the mounting feet position was slightly better.

 

[john_morris_uk]

If you really want quiet then get the builder to fit a Halyard Marine Aquadrive and LOTS of good sound insulation. We have a Volvo 2040 with this set up and you can barely hear it running.
People new to the boat sometimes go below decks to see if it’s actually started!

The Aquadrive helps separate the engine from the boat structure and reduces the noise significantly. They’re much more effective than other flexible couplings that are available such as the Centaflex as already mentioned. All IMHO and experience.

 

[jwfrary]

If you really want quiet then get the builder to fit a Halyard Marine Aquadrive and LOTS of good sound insulation. We have a Volvo 2040 with this set up and you can barely hear it running.
People new to the boat sometimes go below decks to see if it’s actually started!

The Aquadrive helps separate the engine from the boat structure and reduces the noise significantly. They’re much more effective than other flexible couplings that are available such as the Centaflex as already mentioned. All IMHO and experience.

On a larger install I think this is a good way to go. On one this small I would be hesitant to recommend it especially considering the extra length and cost to putting it in the drive train.

other drive of the type to choose from though
Python drive and centa also make some

 

[Tamar]

My friends beta 30hp? Sounds like a little watch when it ticks over, it's around 10 years old, at around 2k revs it's a bit louder but not unpleasant, my 29 hp Perkins is pretty quiet for a 30 year old engine, most of the noise coming from the air intake. I guess all engines make a noise, insulation is part of the solution.