Yanmar 2QM20 - Should I rebuild or replace it? Maybe convert to electric?

[pwilletts]

Most diesel engines are VERY simple...be brave and have a go at it..get a manual and study up and you will be surprised at how much you learn and how much mechanics charge for BS

[Cheechako]

Inspect the pistons carefully for hairline cracks around the ring grooves.

[leveche420]

Originally Posted by pwilletts

Most diesel engines are VERY simple...be brave and have a go at it..get a manual and study up and you will be surprised at how much you learn and how much mechanics charge for BS

Thank you, that is what we have done and we are moving along!! updates on the engine refit here: https://doctorsailboat.com/2018-07-t...-yanmar-2qm20/

[leveche420]

We continue to make progress on our yanmar refit project. Details here: https://doctorsailboat.com/2018-07-t...-yanmar-2qm20/

[Compass790]

Looking good! But you don't say in your blog what any tolerances were. I'm just curious to see how worn it actually was both in liner region & crankshaft main bearing area. Or did you not worry about the tolerances & replace anyway?
With your approach you should end up with a "better than new" engine. When I say better than new I mean longer lasting than the newer engines as yours is heavier & lower revving.

[leveche420]

Originally Posted by Compass790

Looking good! But you don't say in your blog what any tolerances were. I'm just curious to see how worn it actually was both in liner region & crankshaft main bearing area. Or did you not worry about the tolerances & replace anyway?
With your approach you should end up with a "better than new" engine. When I say better than new I mean longer lasting than the newer engines as yours is heavier & lower revving.

I didnt worry about tolerance and replaced anyway. Once the engine was "open" we thought we would rather replace most of the pieces hopping that we dont have do this anymore over the next 30 years

[Compass790]

Originally Posted by leveche420

I didnt worry about tolerance and replaced anyway. Once the engine was "open" we thought we would rather replace most of the pieces hopping that we dont have do this anymore over the next 30 years

Yes that's the best approach if you can afford it. You'll easy get 30 years from it in a normal use setting as long as it's maintained properly.
Old yanmars are longer lasting than new according to scuttlebutt, being heavier & lower revving it's logical.

[Wotname]

Originally Posted by Compass790

Yes that's the best approach if you can afford it. You'll easy get 30 years from it in a normal use setting as long as it's maintained properly.
Old yanmars are longer lasting than new according to scuttlebutt, being heavier & lower revving it's logical.

Especially the QM series as they were originally designed as workboat engine rather than a recreational boat engine. Designed to run all day all week.

[leveche420]

Originally Posted by leveche420

Thank you all for your help! You will be able to follow the progress here:

https://doctorsailboat.com/2019/01/2...-yanmar-2qm20/

Looks like the link above does not work. This one should work: https://doctorsailboat.com/2018-07-the-engine-refit-yanmar-2qm20