The perfect Passagemaker III, propulsion

No, it would not.

Though it is a better idea to buy a engine which is already tuned to operate in a low rpm range.

 

So how can I tune a small engine to run at low rpms...

 

Injector setup mainly. Contact the manufacturer.

 

This might be a good thread to start

 

Not something for this boat in question, but you may want to look at "listeroids."

 

Yep, they are copies made in India, there are still many mid speed genset type engines available, maybe not so easy from the USA, but the rest of the world still uses them.

 

Apex,

With the current type of electronic controlled fuel injectore (solenoids in the basic form), maybe it is now possible to run a diesel at low revs and not glaze it up or damage it....they seem to run soooooo clean that I doubt too much is wasted as was before when a diesel was running below design speeds (70% load for 70% of the time for light commercial). The real commercials run at set speeds for most of the voyage time anyhow.

 

maybe it is now possible to run a diesel at low revs and not glaze it up or damage it...

It MIGHT be , but the load would have to be a high load ,,,for that lower RPM.

The problem with low load glazing is the pressures in the cylinder are too low to seal the rings , which is caused by low gas pressure Behind the ring .

IF the ring is not pushed against the cylinder wall with enough force , the glazing occurs.Resistance to the load will increase the ring scraping pressure.

A heavy electric load or a really good CPP prop would be required to work with the electric injection at low rpm.

FF

 

Yes Srime I know the Listeroid made in India.
When you receive them you have to rebuilt them. They are extremely badly cast, and manufactured.
And they don't pass the EPA. So not admissible anymore since two years ago in the US.
(officially )
Daniel

 

True to some extend John.

As Fred mentioned, you still have to load them proper to live long. In the case Mydauphin has in mind (I assume it is not propulsion), the CPP is not the solution. (If propulsion is the duty, the CPP is the perfect choice)

One or two big alternators (in relation to the engine power) do the trick already.

Mydauphin,
One point I have forgotten to mention in my former post!

When we are talking modern, electronically controlled engines, you must not do any effort, except reprogramming the ECU. You have to find a appropriate mapping to set the optimal figures for the intended load/rpm range.

Daniel,

there are a few better Listeroids on the market. But even they have to be dismantled and finetuned, you are right.

Regards
Richard

 

Can all these engines pass Tier 2 or higher depending when the keel gets laid?

 

That would get you a large fine in the US and Europe no doubt?

 

No, sure not. That is the way every manufacturer tunes his standard engines for different purposes.

Which engnes are you referring to whith the Tier question? The ones Mydauphin wants to use, or the propulsion of my Passagemakers?

 

Tier 2 or 3 or 4 engines.
I guess I refer to both as I cant see anyone using engines that are not Euro and US compliant as there's not much of a market outside these areas hence many engines disappearing..even in China

 

I have Detroit diesels, the old kind on my boat, 2 strokes 6-71s, everything on my boat is like tier 0. I was think of modifying a 2 -71 to run as generator at very low rpm, running waste fuel or biodiesel.