mrsmackpaul

A interesting letter for the cook when you get home Paul

Good job, I can't get over how clean it is Paul

Kt, what model of cummins did this become apparent? I feel it was really a issue from big cam motors onwards Or was it before then Paul

Series parallel is pretty simple, more confronting to look at than it actually is Follow the diagram and you'll be fine Paul

So there's lots to take away from this Water doesn't get trapped in the pump housing causing cavitation The gases, as was describes to me by pump experts (that is their lively hood) aren't hydrogen and oxygen as I think ?? I assumed they were This may only explain cavitation in engines, but irrigation pumps still suffer from cavitation and have motors no water at all goes through Restricting the delivery side of the pump stops cavitation and increases flow Maybe it was my assumption from years of experience and lessons learnt that is the pump delivering more than it can draw It was certainly explained to me along those lines and proved to be correct over the years Poor design in motors causes this cavitation problem and not trapped air Also as long as a centrifical pump has the inlet and labyrinth seal on the inlet end covered and no air leaks on the inlet and a supply great enough to supply the pump, the pump housing will expel all air with seconds of running ÷÷÷÷÷÷÷÷÷÷÷÷÷÷÷÷÷÷÷÷÷÷÷÷÷÷÷÷÷÷ So funny line above to slightly change what I'm saying in reply to this thread, to ask questions or maybe some thoughts Were on the liner did this 90° issue happen If it isn't hydrogen and oxygen gas, then what gas is it ? ÷÷÷÷÷÷÷÷÷÷÷÷÷÷÷÷÷÷÷÷÷÷÷÷÷÷÷÷÷÷ I feel it maybe still the pump delivering more than it can supply Here is my thoughts, based no science at all The coolant system cant be at 45 psi all over as suggested, need pressure change to get flow So maybe 45 psi at the thermostat housing or radiator Maybe 25 psi at the pump inlet But for flow the pressure has to be lower in one spot and higer in another for water or coolant to flow, other wise it is just sitting in a puddle or a bath tub or dam or pond I do feel that there was a time were manufacturers got to smart for their own good and changed the make up of metals in the late 70's and early 80's and every car came with rust built in I wonder if engine manufacturers had a similar issue and materials weren't as good Porus blocks and transmission housings were pretty common for a while So with a possible cheaper stinger use of materials and the demand for more power requirements and then more cooling requirements Was this the "perfect storm" for cavitation to become a issue in some manufacturers engines ? I feel there is probably a lot of contributing factors here and not just one cause 14 litre Cummins nearly doubled in out put in little over a decade IH were under financial strain and trying desperately to keep up and had a bad history of not developing products fully Thanks for the info Geoff, all very interesting stuff Paul

I'm impressed by the this whole operation Keep us posted, this something most of us will never see Top job Paul

So not knowing what I'm looking at here, this tool pulls the bearing offthe shaft and out of the box while leaving the shaft installed Is that correct, pretty smart idea if my understanding is correct I guess the other side of things to think about is, if you have a issue in the box your unaware of, this is the time to have a look while it (the gear box) is on the ground out from under the truck But.that is a smart tool if my understanding is correct Paul

Steady on there Geoff, that's a pretty serious accusation I have tried my best to explain something to you, I never claimed to of been a expert in physics I never finished high school However, that doesn't mean I'm stupid either, so perhaps stop the insults I can't teach someone that doesn't want to learn, someone can't learn if they think they know everything A simple comment about is air trapped in a pump housing turns into this mess Ah well, maybe someone has learnt something here, maybe they are convinced now that I am dumb ass and don't know my ass from my elbow due to not having a proper education in teaching and thermal dynamics Dunno ??? Not a lot more I can add here, I have tried my best Back to 300+ Paul

Nothing like chowing down on a good sausage ????

I already have a few posts ago As I said, Im not getting into proving I'm right, just saying it as it is Paul

The coolant isn't boiling, it's separating Very different Paul

Very true Joey When learning and someone misses a gear, the first thing we naturally so is panic and shove the clutch to the floor OOP's Makes it even worse and we try even harder Oh dear, we need to learn some how Paul

The coolant doesn't vapourise, it turns into two different gasses and this actually happens in the pump impeller Paul

So cavitation occours when the liquid, in this case water, seperates into gasses Oxygen and hydrogen in the case of water This happens when the delivery side of the pump isn't restricted enough or supply side is to restricted Pumps pump less when this happens, like Joey sort of said in different words, centrifical pumps can't pump air So how to stop this happening in motor, run the right thermostats, don't over rev, maintain a good pump So why isn't air trapped in the pump housing as Geoff suggests As soon as the pump starts half of the pump or there abouts is under a lower atmospheric pressure So what does this mean ? What's easier to shift, a bucket of air or a bucket of water ? A bucket of air of course, so the low air pressure causes the air around the pump to try and escape and the only way out is through the on the delivery side So why are some motors not subject to cavitation and others susceptible Pump design and location on the motor has a lot to do with it Detroits pump on a 2 stroke is small diameter and down low, this means it makes less pressure or perhaps it makes smaller pressure difference between suction and delivery Macks are also better designed So the air on cavitation is coming from the liquid been shifted, not staying liquid all the time There is no air getting into the motor, the liquid in the motor is changing state and once the liquid passes through the pump returns to liquid again The cavitation is like water hammer on the pipes in house, turns from liquid to gas and back again, over and over again The coolant system has a type of water hammer No wonder some designs of motors are susceptible to this and it's hard to stop So trucks got more power and bigger coolant systems, which in turn leads to higher coolant flow, this causes cavitation Many a Cat earthmoving machine suffers from this when thernostats are removed So I'm not having ago at anyone, but it's very clear that some of our standings are not correct on pumps and shifting of liquids and how a centrifical pumps actually work There isnt a suction side, even though we call it that There's a low pressure and high pressure side on a centrifical pump Positive displacement pumps have a suction side, so the supercharger on a 2 stroke Detroit is a positive displacement pump Anyway enough waffle from me I can explain further if needed but won't have a big long drawn argument trying to prove what I'm saying is write Happy days everyone Paul

That was me and it was a Pomy video I don't mind processed canned meat Paul

When a motor is rebuilt, generally I would remove as much from the cooling system as I can Leave the radiator cap off until operating temp is achieved and the thermostat opens Any air trapped in the motor is released, top the cooling system off, put the radiator cap on, take for a test drive and check everything is okay I reckon thats pretty standard across the world and open to correction if I'm wrong and missed a step Joey your right about cavitation, but what is it, we know the result of it But what causes it ? I had it explained to me many years ago in a way that made sense Were does this air come from ? Paul

This doesn't really explain were the air comes from once the air is expelled What is this tricky thing called cavitation ? What causes it ? And how can that is alledgedely trapped in a water pump be such a issue ? How doe's a centrifical pump work ? These are all things that have to be understood to understand how cavitation occurs and what is required to stop it Ask a irrigation farmer that relies on centrifical pumps about cavitation and it's effects on pump life and the pipe work connected to the pump I can tell you as a irrigation farmer, that water will not get stuck in the pump as your suggesting The moment a centrifical pump is primed and spinning that water is gone If it wasn't the the pump wouldn't be primed So keeping this in mind, assuming that bit of information I have suggested is correct Were does this pesky air come from that causes cavitation? I can assure you it isn't the injector sleeves And why do some makes of motors never suffer from this and others do all the time ? I'm trying not to be condescending here, we all learn things differently and I'm trying best to teach people here Cavitation isn't simple like people think Paul

John Deere sold plenty of industrial engines, lot of farm irrigation pumps and generators had/have John Deere engines Dunno about Mack, I'm thinking Kato cranes in Australia But I'm fairly sure they were a crane bolted to a Mack chassis Paul

WOW thats a lot of typing Anyway, lets keep it simple because Im a dumb ass If the air is expelled from the system, why does it have a pipe, going up fown, left, right or were ever to bleed trapped air away ? As once the air is expelled, there is no air left So whats the purpose of this pipe work ? Paul

Well I guess engine blocks and heads must be different in the southern hemisphere than in the Northern hemisphere as there are plenty of spots in castings were air can be trapped So keeping this polite and well mannered If air is simply trapped in the water pump as suggested, why do manufacturers put a little pipe or hose around the pump to the thermostat side ? Paul

Dunno if you blokes have scones in Yanky land or Devonshire tea's or any of that jazz anyway, when sausages are more flour than meat at a butchers, if we are been really cheeky we may ask for so many kg's of scones ha ha ha Paul

I could agree with Geoff, but we would be both wrong then The first thing people need to understand is what cavitation is It isn't just air in water Anyway I'm sure you'll have quotes and stories that will shoot me down in flames and I'm not getting into a I'm more right than you type of conversation We need to understand what cavitation is and what causes it and how a pump actually works and if air really got trapped that easily in coolant system then there would be bleeders all over the block and head and any little defect in the castings Anyway I'll leave you to think you're right as I'm only a dumb ass skippy the bush kangaroo from Australia ha ha ha Paul

Come to think of it, a Detroit water pump is down really low so plenty of atmospheric pressure to lift any air out Paul

Because Mack built motors properly Probably need a bleeder on a Cummins as Cummins were susceptible to cavitation Detroit (2 stroke) I have never heard of any cavitation issues IH was like Cummins and renowned for cavitation problems Paul

Floor boards ??? Hope the termites don't eat it 😯 Paul