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Forum Index : Other Stuff : Diesel (Petrol?) Engines for Generators and Pumps

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mackoffgrid

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Joined: 13/03/2017
Location: Australia
Posts: 460
Posted: 10:46pm 15 Aug 2019
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Dave, Tony

I'm quite a bit away from doing anything about building or acquiring more engines for water pumps or generators.

Comments made in Diesel Engine Muffler  and  Diesel Engines - water injection  were referring to using larger engines and running them at a fraction of their rated power, and at low revs promoted longevity and a quieter unit.

In my naivety, I have long believed this and have argued with others that it can't be good to run Diesels near full power.  Most things works better at low duty than high and I don't see why Diesels are any different.  My knowledge of engines is pretty weak so I can't argue specifics.

So I'd like to hear comments and suggestions as to what engines would be good to deliver up to a solid 5-10kW generated power with surge overhead, or similar power to pump water.  I prefer to stick to Diesel as I don't want to store petrol as well.



Cheers
Andrew
 
Warpspeed
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Joined: 09/08/2007
Location: Australia
Posts: 3332
Posted: 11:41pm 15 Aug 2019
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The main problem with running piston engines at very low rpm has to do with having a heavy enough flywheel to deliver a constant torque to the load without having massive cyclic speed and torque fluctuations.

This is at its worst with a single cylinder four stroke engine.  
With more cylinders and/or higher rpm, much less flywheel inertia is required to produce smooth running under load.

No problem running diesels continuously at full rated power.  Its done all the time in marine, and power generation, or pumping applications.
Cheers, Tony.
 
mackoffgrid

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Joined: 13/03/2017
Location: Australia
Posts: 460
Posted: 12:20am 16 Aug 2019
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I was thinking of a 80's or 90's 4 cyl car or small truck diesel?
 
Warpspeed
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Joined: 09/08/2007
Location: Australia
Posts: 3332
Posted: 04:52am 16 Aug 2019
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Its not something I really have any personal knowledge or experience of.
A small diesel marine engine might be a possibility ?
Cheers, Tony.
 
Revlac

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Joined: 31/12/2016
Location: Australia
Posts: 347
Posted: 09:19am 16 Aug 2019
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Diesel powered water pump.

Had the need for a decent size water pump years ago and these little petrol powered fire fighting units weren't up to the task, also had some single phase electric pumps but was costly to run all day.

The idea was to shift a lot of water quickly and efficiently without loosing as much in evaporation.

Already had a good size pump, Dad and I just needed something to drive it, found an old diesel car engine Nissan SD22 in very rough condition cracked head etc. other bits missing, but fixed it up a bit.
Found a base frame at the local TIP, mounted the pump and motor on it, made up a mount to fit the pulley on to the flywheel.
No need to do anything about a governor, the pulley is about 2:1 ratio so the motor runs at about 1500rpm more or less depending on what water pressure is required.


This was 17 years ago
Still use it on occasion.

Some after thoughts.
A 3 belt pulley would have been much better than running just 2 belts.
The radiator is a bit of a waste, would do better with a heat ex-changer, using some water from the pump for cooling.

Just a working example.

That muffler has rusted off long ago, not so noisy.
Edited 2019-08-16 19:24 by Revlac
Cheers Aaron
Off The Grid
 
Revlac

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Joined: 31/12/2016
Location: Australia
Posts: 347
Posted: 09:37am 16 Aug 2019
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Diesel Powered Generator

A friend was in need of decent generator for large power tools and some 3 Phase.
After much searching around Dad and I gathered up enough parts to start putting one together.

To start off There was a generator with a Blown up motor and it had also been though a flood...what a mess.
The generator was an old Stanford type with the transformer reg in it, and I think it was about 63Kva or so.

Next, needed a motor to drive it....difficult finding something that is of suitable size.
Another friend was moving house and had half of an old leyland truck, the motor was about the right size.
Thank you friend, Thant's what we need and you don't anymore.

All mounted up on the generator frame, the front axle and wheels from the truck where mounted under the whole unit to make it portable.

Now the truck engine governor was ok to keep the revs close enough for light loads welders, electric pumps, lathe, mill etc. would run an electric motor up to about 15Hp, more than that and the frequency would drift out too far.

Anyway the owner is happy with it as it is, and it is much more power than he needs.  

For this setup to run more powerful gear it would need the Governor setting up and likely use an electronic governor to do the job properly.

Just saying these things are doable, just depends on the size that is needed.
Going a bit oversize leave's plenty of headroom to play with.
Depends on what one can buy at a price that is good for a DIY project.
Cheers Aaron
Off The Grid
 
BenandAmber
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Joined: 16/02/2019
Location: United States
Posts: 861
Posted: 06:07pm 16 Aug 2019
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I really like reading about you and your dad

Dads are one of those things that we dont have forever
 
Davo99
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Joined: 03/06/2019
Location: Australia
Posts: 519
Posted: 11:36pm 16 Aug 2019
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  mackoffgrid said  
So I'd like to hear comments and suggestions as to what engines would be good to deliver up to a solid 5-10kW generated power with surge overhead, or similar power to pump water.  I prefer to stick to Diesel as I don't want to store petrol as well.



That is a wide power range, 100% min to max.
Lets say you want 10 KW.
Firstly, going with Diesel you will want to keep your eyes open. Engines around that range are  well sought after and not normally Cheap.

Here are some type suggestions. They come up occasionally and not to regularly in my observation so get one when you see one because it could easy take a year to find another near you at a sensible price.

These engines being new aren't a bad price.
Changfa Type

This one has the power you need and are a VERY reliable and well regarded unit.
They can be neglected for years and easily rebuilt with the spares kit that comes with most of them.

This is a similar type used:
10HP Changfa

Bit down on the power you want, kind of in the middle of spec. They are a good reliable unit and spares are available on aliexpress and the like cheap as chips.
You wouldn't be running this one too much in your output spec but none the less you would get many years out of one with basic maintence..... Like change the oil which many in their native countries do not get.

I have a Hatz and although I can't say I have worked it a lot, it is a very nice , smooth running engine.  They make them in larger power outputs  so if you see a 1b40, probably around what you want.

Hatz

From there you start getting into serious money unless you get lucky.
These Kubota/ yanmar Multi;s are again popular and expensive but very good engines.

inline

They do them in a range of sizes  so check which ones come up near you. These are quiet and very reliable engines and One I look out for all the time.

Car engines might be ok at the upper end of your power spec. While running them slower than normal is good, too slow is not. You could lean on the things a bit though to get the power up and still keep them happy.

This all said, my question would be how much water do you need to pump? If it's just the occasional thing for a few hours, then I would go with petrol. It would be a much cheaper option and an engine with decent oil changes could last a long while. If its a daily use thing, then yes, pay the money and go Diesel.

There really aren't any bad Diesels I am aware of, see what comes up that does the power you want and as long as it is in good condition should give you good service.

The only one I'd say be wary of if you do have a lot of pumpoing to do is the Chinese Vertical Cylinder models.

China Vert type

These things come in a wide range of sometimes questionable outputs and even more questionable pricing.
I have 6 or 8 of these things and they are rough, noisy as hell and the longevity from what I have seen is no better than a Chinese Petrol engine.
They are diesel though.

They are getting better it seems. the first ones I got were real POS till I got into them and sorted them out but the later ones seem much better.  Based on my experience with plenty of them, I would not expect better longevity than a petrol engine and given the price if buying new, I would say buy a petrol. Given you could buy 4 petrol engines ( at least) for the price of one of these, the petrols IMHO would be a better deal in reality.  I have got mine all used or as new parts but I would NEVER pay full tilt for one. I'm not saying they are bad engines, rather they aren't wonderful.
I have one with a water pump on it( or is that 2?) and one I'm setting up with a couple of car alts and a few I bought because I'm a diesel tragic and have no self control when they come up cheap.
I have been lucky and got all mine at bargain prices but the prices they normally retail for, especially the higher 10 Kw output models is often poor value for money IMHO.  

The other thing to be aware of if you are doing a replacement is they are a LOT bigger and heavier than a comparable petrol engine. I went to put one on a rotary Plough I bought and even though the petrol engine that came off it was an old 8 HP, I couldn't get a 6 HP diesel on the thing by a long way. I got an 8hp Chinese petrol engine and have worked it's butt off and it's been perfect. The diesels also require a level of Technique, courage and commitment to manually start where the petrols start soon as you look at them virtually.  Electric start on a China Diesel is a GREAT investment! OTOH, I think nothing of Pull starting an 18 HP china petrol engine.

The horizontal China Diesels with the Flywheels are a wind up Job. You Hold the Decompression lever on the head, wind the flywheel up with the starter crank and then drop the decompressor and off they go. They are great fun when you have a few mates around Playing who can start the diesel with those that have never come across them before. If you really want to Bruise a few ego's, play the same game with a twin Flywheel Lister! ;0)

I will say this, the vertical china diesels do seem to outperform the petrol Models in a given size pump. I took mine to a mate to fight an expected Bushfire and his petrol pump although rated higher than mine, put out no where near the volume and pressure.
I thought that may have been a one off but now having an 8 HP petrol and a 6hp Diesel, Diesel definitely is the stronger engine even though it looks like the pumps are identical.

You choices are a bit dictated by what output you WILL USE, If it's 5 then you are probably a bit short for a multi engine but if its 10 and you will have a suitably size pump, then no problems.  A small  car engine suitably geared so it is seeing some load and run for decent times would be fine. There are limits though and while it is OK to under drive engines, You can't successfully run them for long periods with effectively  NO load on them.  They need to get heat, oil pressures, gas flows and other things happening which won't if the things are effectively idling all the time.
 
Davo99
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Joined: 03/06/2019
Location: Australia
Posts: 519
Posted: 11:43pm 16 Aug 2019
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  BenandAmber said  

Dads are one of those things that we don't have forever


Exactly!

I missed a LOT of years with my father through some very bad Choices he made but now she is no longer around we have become like a family again. He's 80 and I know the clock is ticking and I live in fear every day of that Phone call.
I wish I could have done more with him like the projects above but wasn't to be.
 
mackoffgrid

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Joined: 13/03/2017
Location: Australia
Posts: 460
Posted: 07:45am 17 Aug 2019
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Aaron, that pump looks like a beautie, and about what I was thinking about.
Its a few years aways yet, probably.  
Very much overkill but I liked the sound of the old perkins 3 or 4 (?) cyl engine that was in the MF40.

Cheers
Andrew
Edited 2019-08-17 17:47 by mackoffgrid
 
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