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Good point. However in a PD pump you do get "slippage" as pressure increases, so effectively get a (somewhat) similar curve. However, contrary to Dave's post, flow rate in PD pumps increase as viscosity increases, as increased viscosity tends to reduce slippage.Quote:
Originally Posted by bee utey
And what will this achieve ?Quote:
Originally Posted by Blknight.aus
The 2.8 engine tolerances are designed around an xW-40 so that's what you run, right from the beginning, and the pump is always primed otherwise it'd take more than a minute to pickup oil.
The pump is flowing oil almost from the moment it starts moving, it's just that the pressure may not be anywhere near what is deemed 'normal' for a few seconds.
and for that matter, is there ever such a thing as a 'dry' start ?
As soon as a plain bearing starts to move it's gliding on a hydrodynamic wedge of fluid, the oil that's leftover from the last time the engine ran.
If it wasn't, we'd be swapping out bearing shells pretty frequently.
Disregarding the top end of the engine for a sec, the only reason we have a pump is to inject cool oil into the journal before the current oil becomes overheated (splash feed still works well up to around 1000RPM) and really, how much difference is there in startup viscosity between a 0W-40 and a 15W-40 oil on the Gold Coast in Autumn ?
In terms of time to pressure there would be nothing in it.
I'll let you into a little secret too, the 0W-40 will shear a hell of a lot more quickly than the 15W-40, (lots of viscosity index improver's in the 0W-40, not withstanding the thickening from soot) and the only 0W-40's available are petrol biased oils, (SM/CF) ie. they don't have the robust, heavy duty diesel additive package of RX Super and its ilk.
I'll take the more robust additive package anyday.
have another read, pay attention to the word primeQuote:
Originally Posted by isuzurover
then check the loading and torque curves required to create a given flow rate with a thin fluid then a thick fluid.
your point about pump slippage is valid when operating up nearer to the limits of a pumps maximum rate pressure but down in the sub 100psi world, nahh not so much. if you were getting an obviously perceptible difference in flow rate VS given RPM at 60ish psi with the minor variation in viscosity thats on the cards in this discussion I'd suggest that a, you need a new pump, b, your balance plates ports are blocked or most likely C, your pre pump sealing is questionable.
and as already pointed out... no points for bringing irrigation pump charts to a hydraulics discussion.
Hi All
You have got to love the ebb and flow of these threads! ;)
First a question to Uninformed;
With all that has been told in this thread about what happened to the motor after it was over filled.
Has anyone put their finger on the way the oil was actually picked up, causing the run away?
Other uses for a 300TDi, as it now looks like I have a spare motor. --- maybe this is a question that could be a start for another thread.
Looking at the 300TDi / 2.8TGV from a Dairy farmer's perspective, how would these motor's work as a irrigation pump motor driving a traveling irrigator and what size pump would you couple to it?
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They would work excelently but you would want an auto shutdown safety system on them
any pump that runs at about 2500 for 100HP would be the go.
Ive got a hydraulic winch, does that count :confused:
having little to no knowledge on the subjects of hyd and oil. I personally cant see the difference in running the RX Super over the other weights Dave mentioned. Its not cold here. I change my oil and filter every 5000k and RX Super is my choice (easy to get in 20l drums and a fair price)
I did make 2 hyd rams once.....but I was being told what to do where on the lathe by the guy that designed them....that was :cool:
Hi SergQuote:
Originally Posted by uninformed
With my posting I was actually wondering about the matching of the characteristics of the 300TDi / 2.8TGV engines with the requirement characteristics of a load, for an example when used in a stand alone situation as such as a irrigation pump set.
Have you any pictures posted here on the forum of your hydraulic pump set up on your Land Rover?
That is my choice of oil as well and I have never had any problems due to using this product.Quote:
I change my oil and filter every 5000k and RX Super is my choice (easy to get in 20l drums and a fair price)
If you have already dropped the running in oil and started to use the RX Super I would stick to it now.
otherwise you could find a similar type of oil with the same additives as RX Super, but with a lighter viscosity rating.
One of your previous post, you mentioned that the 2.8TGV was down a bit in power since the rebuild. I would wait until the motor has done say 20,000 Klms as it would most likely have freed up by then.
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yeah I was thinking it may need to break in a bit more. RX Super has gone in and will continue to do so untill a better or equal cheaper option comes along. In other words Im happy with it.
The hyd set up is a MD pto direct driving a cross hyd pump that will flow 60lt/min. I have a 20 or so ltr resivour, with internal filters. A 12v solinoid control valve that is controled by a simple remote. Pressure relief valve and inline spin on filter in there also. Winch is a mile maker 9000lb and I had a double over center valve fitted directly to the motor for safety.
regarding using the 300tdi as a stationary engine. I was onky reading the other day about a guy making his own firewood processer. The general consensis was that stationary engines are bigger lower tuned engines to cope with the conditions. Ie if you had a 2.5ltr engine that made 100kw in a car and you needed 100kw stationary, that type would generally be 3-5 liters capacity.....
Damned near impossible to find any xW-30 HD diesel oils in Australia, although they are available in the cold parts of the US and Canada (and you have to really look there too)Quote:
Originally Posted by wrinklearthur
About the only time they run xW-30 HD diesel oils over there is during the depths of winter.
I ran Mobil Delvac 1 5W-40 for years and years, and it is a little easier on the starter @ -5* compared to a 15W-40, but there isn't much in it.
I use a 10W-40 HD Euro diesel spec oil these days, purely as supply is easier and cheaper for me than trying to get the Mobil brew from the depot 100km away.
Which brand are you using Rick? I'm feeding my work car 10w40, Agip is the easiest to find locally.Quote:
Originally Posted by rick130