Author Topic: WI  (Read 8494 times)

BruceM

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Re: WI
« Reply #45 on: June 16, 2018, 07:04:32 PM »
Alas, those pulse diaphram pumps are run from pulsing vacuum- hooked up to the gas engine intake manifold I'd guess.

The CS intake manifold vacuum isn't likely strong enough to operate one. 

glort

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Re: WI
« Reply #46 on: June 16, 2018, 10:04:47 PM »

Normally Bruce they are Connected to the crank case on both 2 and 4 Stroke engines.

They work very well and I'm sure the Carnkcase pulse as I have observed on my own roid would be more than enough for them.


BruceM

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Re: WI
« Reply #48 on: June 17, 2018, 02:47:06 AM »
Is is likely to be able to draw up water 36 inches?  Sure looks like a sweet solution- didn't realize they existed for regular engines...I'd only used them for RC engines when I was a young man. 

glort

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Re: WI
« Reply #49 on: June 17, 2018, 03:35:57 AM »

I have no experience with them Bruce but I would think they would be more than what you need.

They are used on large outboard engines as well as go karts, ATV's, Jet skis and other things. I was looking at the Mikuni originals and they are specified at 65 Lph.  For that they are going to need decent pressure.
I think 1 PSI would do a meter of lift.

BruceM

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Re: WI
« Reply #50 on: June 17, 2018, 05:27:21 AM »
I'll have get one and test it, it might be just the ticket.  Thanks for the great idea, Glort!

glort

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Re: WI
« Reply #51 on: June 17, 2018, 07:03:44 AM »

Was your Idea, it just reminded me of the right part I should have thought of before.

I think You could tap into Crank case or exhaust. I Imagine with the run you have, there might be a significant pressure spike in your exhaust pulses. If not, tapping  into the crankcase door will surely do it. If they will run off a 2 Stroke pulse, there is no way they are not going to run off a 'roid pressure wave.

Was watching this interesting Vid on WI earlier.
Bit different to what we are looking at but I found it interesting just the same.

https://www.youtube.com/watch?v=skuIkE93TR8


ajaffa1

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Re: WI
« Reply #52 on: June 17, 2018, 08:44:06 AM »
Good thinking guys, my ride on lawn mower uses one of those as a fuel pump, it ran faultlessly for 6 years until the engine head gasket failed and the crankcase pressure increased. Bloody thing vented hot sump all up my leg. Replaced the head gasket and flushed out the diaphragm pump, runs like new.

Not sure how much pressure there would be in a Lister crankcase because they already incorporate a spring steel diaphragm to release the pressure. If it works you could fit two one for WI and one to pump fuel rather than gravity feeding.

Very interesting.

Bob

glort

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Re: WI
« Reply #53 on: June 17, 2018, 01:46:26 PM »
Quote
Not sure how much pressure there would be in a Lister crankcase because they already incorporate a spring steel diaphragm to release the pressure.

Yeah I thought of that Bob but I don't see it being a problem.
On 2 strokes which these things are widely used on, the crankcase pulses are very low because the things are only ever moving air through the ports.
On a 2 stroke the pulses would be weak but rapid, on a Roid they are going to be deep but slow. Given the amount of water Bruce requires, they could do about 5% their rated output and still be there.

the thing is, these pumps work both ways. The CS crank case breather system is designed to keep a neg pressure in the crank case so will have a strong Negative pull that way even if the down stroke is vented. The upstroke of the piston will Pull the diaphragm in the pump up, the down stroke will allow it to relax. Pumping will be great I reckon.

Most small petrol engines either have a similar system with a reed valve incorporated, or the China 4 strokes tend to just vent the crank case gasses up through the push rod gallery's into the rocker cover and the gases are taken straight from there to the inlet manifold.

I was reading the other Night where they have now put a Limit on the F1 cars oil consumption.
The cheeky engine designers were Putting like 25L sumps on the engine and deliberately  feeding the oil vapors back into the manifolds to get better fuel consumption. they WERE fuel limited, sumps could be as big as they liked!  Things would use 200L of fuel and 50 L of oil to get them round a race.  Now they are only allowed to have a max Oil consumption.
Next thing will be they have 40L windscreen washer bottles full of water/ meth mix.

Don't laugh, 300ml/ min of 50% water methanol works out at 14 HP worth of additional fuel. They could probably inject 2L min into those screaming things with the huge CFM going through them and blow past everyone else on the field..... that's if they ran 50% meth and not 90 or the like.


I love my Mower. A 30 yo Honda with a twin Cyl in line water cooled engine. Thing purrs like a Kitten. I take REALLY good care of that because as they say, don't make them like that any more and I'm not too sure they would even do parts.
I hate petrol industrial engines although I have a ton of them.  I am looking for a mower with a clapped motor in reasonable condition to do a Diesel conversion with one of my many little engines.
Got a John Deer without a Deck to use as the tractor round the place because I don't want to stress the Honda.  I has a Kohler engine which is in completely disproportionate condition to the rest of the machine.  Excellent runner and never seen a puff of smoke and compression is through the roof for a crappy petrol stationary engine.  Very smooth runner too surprisingly.

ajaffa1

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Re: WI
« Reply #54 on: June 17, 2018, 10:58:37 PM »
Most small 2 stroke have a small diaphragm pump built into the bottom of the carburetor. They have a lift pipe and a return to the fuel tank. They shift a lot of fuel, as you will know if you have ever had the return pipe break or blow off.

Only trouble with a four stroke with this sort of WI is that you are going to get two injection pulses for every combustion stroke, doubt it would matter but you might want to experiment with a needle valve for correct dosing.

Bob

BruceM

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Re: WI
« Reply #55 on: June 18, 2018, 04:16:15 PM »
I've got a pulse pump on order; too interesting to not try out.  Bob raised an interesting point; with 2 diaphram actions per crankcase per intake gulp, you do get dribble into the bottom of the intake manifold unless you implement a little shallow dish to catch it.   That's the advantage of Mr X's vacuum fed approach- all water is entered into the peak intake airstream.

 I also ordered a kit of RO tubing, float valve and shut off valve for $13. so that I could do a gravity fed constant water level version of the intake manifold vacuum fed WI.  The diaphram pump could also feed a small constant level tank- by just having an overflow port to drain back to the supply bucket.  All quite cheap to implement so worth some dabbling to find a nice setup for CS WI.

BruceM

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Re: WI
« Reply #56 on: June 21, 2018, 04:12:24 AM »
I got the vacuum pulse type diaphram fuel pump today and tested it hooked to the 6/1 crankcase.  It works nicely but has a total lift of only about 13 inches of water (zero flow); intake and outlet combined, it matters not where the pump is between them.  At 10 inches it pumps a steady flow way more than needed, flow starts falling off rapidly from there. These pumps are direct single diaphram types so pumping lift can be no more than the vacuum in the crankcase.  I'm sure some CS engines with less hours may have better crankcase vacuum, but that's all I've got.  It's lower than typical gas lawnmower engines because the crankcase volume of air is so large relative to piston displacement volume, I think.

So I decided that gravity is pretty reliable and cheap and I've had enough pump fiddling. The float valve and plumbing kit came along with the diaphram pump. I've got the two tanks made up with fittings, float valve and plumbing mounted.  Tomorrow I'll do some flow rate adjustment testing and then will add my little solenoid valve for Picaxe control.  I sleeved down the 3/16 ID brass tube in intake manifold to 1/16 ID for starters. I'll have the top of the regulated water level in the float filled tank just below the brass intake manifold inlet blow the manifold, so I can see the static water level in the supply tubing. The intake manifold will pull it up the last 1.5 inches.  I used clear Sterilite storage containers (that I had on hand) for the two water tanks so monitoring them will be easy. The 5 gallon supply bin is intended to be filled to 3 gallons and low enough that I can fill it easily.  The big lid will allow me to fill it from a 5 gallon bucket.

I'll do photos and/or video once I get the bugs worked out,







EdDee

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Re: WI
« Reply #57 on: June 21, 2018, 10:29:07 AM »
Hi Bruce,

I am using a gravity/float bowl type setup....has worked flawlessly for me in the past... (I didn't want additional pumps and things that could go wrong....)

I have a 3mm copper pipe that sits center of airflow in the air intake, coaxial to the intake manifold. The copper pipe stops slightly inside the intake port on the head (1/2" or so).... There is no constriction at the end of the pipe, free flowing...

The float bowl can be height adjusted so the level of the float bowl is around 4 to 6" below the level of the intake center (This will vary according to the length of water feed pipe you use, your air filter, and of course the air intake plumbing... also, be careful to prevent multiple dips in the water feed pipe, cumulative head is a bugger on a low pressure system) .... Adjust this height to change water flow. As soon as you restrict the pipe and put a nozzle on it, it gets prone to blocking... There is little difference in effect from mist to droplet, but droplets do work better.

With the above arrangement, there is no chance of flooding the engine, as intake draft is required to induce water...set and forget.... Oh yes, one small addition was a small valve on the water line to allow for water shutoff, seldom used, only when the tube was withdrawn to prevent spillage ultimately...

In the beginning, I shut the water off before shutting down and turned it on after warm up, ultimately, I ended up simply leaving the valve open, there was no ill effect on my system either...

Cheers
Ed
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BruceM

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Re: WI
« Reply #58 on: June 21, 2018, 03:43:17 PM »
Ed, Thanks for the info on your successful gravity-float valve-vacuum WI setup.  I'm intrigued that you had about 5 inches of water vacuum; I'm guessing the engine in question isn't a CS type? Perhaps you were thinking 4 cm which is just what I measured.  I measured my 6/1 Listeroid running intake vacuum at about 1.75" in the middle of the intake manifold and airstream.  Your coaxial tube projecting into the head inlet (good idea and easy to implement ) might be that much more effective but it intuitively seems unlikely to me. I'd really like to know if this 4-6" of water vacuum at inlet is on a CS type engine!

I did note that my engine didn't complain a bit about modest rate WI when cold, but I didn't try starting cold with water. Like you I like things as simple as practical. 



« Last Edit: June 21, 2018, 06:02:09 PM by BruceM »

glort

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Re: WI
« Reply #59 on: June 21, 2018, 05:13:21 PM »

If I ever tame my Jackhammer, I reckon I'll try a Carb off a Bike or something like a 2" SU..... if they can still be found.
Instead of administering Fuel, no reason why they wouldn't work with water and be highly tune-able.

I'm surprised the pulse pump wasn't more effective.  It would be interesting to see how it went using exhaust pulses which would be stronger than the crank case although I would have thought that would have had plenty of pulse to it. My roid exhales plenty hard through the breather just rolling it over by hand on the flywheel.