Jump to content

Tobias

Settled In
 View Profile  See their activity

  • Posts

    206

  • Joined

  • Last visited

  • Days Won

    2

 Content Type 

Posts posted by Tobias

    Seeking Solar Panel Advice

    in International Forum

    Posted

    Hej, Tuko!

    Have a look at the Ctek 250s!

    Mppt solar charger and split charge in one unit.

    You'd want a separate battery for the fridge so that the starter battery never is Compromised.

    Connect starter battery to one post on the ctek. Solar panel to one and aux battery to one. Engine charges borh batteries when running and solar panel takes over when engine stops. It eveb tops the starter battery from the solar.

    The ctek is a bit pricey but they are top quality and this unit just solves all the things you want on one box. Fit and forget solution.

    Tobias

    Hydraulic winch pump setup - Yet another one...

    in International Forum

    Posted

    Thanks for all the great input.

    Sorry for mistakenly saying Team Idris used two stage pumps, it was in fact 'aniesigh' who sold one about a year back and I got confused.

    I haven't heard anyone critisising my calculations on wheel speed / line speed, which was really what I wanted to find out.

    I will elaborate on why I feel dual-stage pumps or motors are a good thing, so that this can be discussed better.

    I have only heard arguments pro-engine PTO driven pumps.

    My winching experience is only to a very small extent Swedish style challenge events. Most of my winching has been recreational off roading where we have been using various cheap electric winches, Warn 8274, PS pump powered MileMarker and gearbox PTO powered on Scania SBA 4x4 military truck (11litre diesel and autobox)

    The best drive assist of all is on the Scania. I have tried to look for the gearings to see how it is set up, but on that one it feels as if the wheels and the wire moves at almost the same speed.

    Having experienced that and how well controlled the self-recovery feels with reasonably synchronised line speed and wheel speed was, is my motivation to at least try to get them close. I also like the way the autobox/torque converter makes the accelerator work as clutch/speed control, just as when driving with an autobox. For people who don't like autoboxes, don't start arguing for manual. I've made up my mind a long time ago which I prefer and installing a better pump system for my winch will not alter that.

    The 8274 shines in the drive asisst department for exactly the opposite reason that the Scania also shines. Speed difference when loaded and unloaded.

    When drive assisting with the 8274, the winch speed drops dramatically with load, wheel spins a lot and line moves slowly. As soon as the wheels get grip, the load decreases and line speed picks up, preventing a car with some temoporary traction from having to slow down too much to avoid over-running the wire.

    Ideally I think I want the wire to move as fast or slightly faster than the wheels when unloaded and for drive assist and also power requirement, it can move slower, but no slower than half as fast as the wheels. Here is where the dual stage pumps come in. At low load, both provide flow and the winch line runs very fast. As load increases (pressure) one pump is bypassed and the speed drops, as well as power requirement. This would give the automatic line speed for tetrievel of the slack in the line when drive assisting wheels get a bit of traction.

    So my calculation show a no-slip wheel speed of 118 m/min at 2000 rpm 1st gear low. With twin 63cc pumps and 80cc motor I would get a line speed of 50-100m/min depending on how much wire is on the drum. With Gearbox PTO, wheels and wire always more in unison, except when the transfer box is put in neutral. With engine PTO, as rpm decreases below torque converter stall speed, wheels slow down and stops wile the wire still moves.

    A single 63cc pump at 2000rpm and 200 bar pulls about 42kw, the limit for the mechanical dog clutch I've seen is 40kw.

    Hydraulic winch pump setup - Yet another one...

    in International Forum

    Posted

    Right...

    I have read all the threads I could find and here is where I stand.

    I want to install a good sized set of pumps in my RRC to drive the MileMarker winch.

    I reallt like the idea of having twin pumps, where both work at low preasure and only one at higher. This I expect will give a nice feedback on when the load increases as speed will drop and also improve control in high load conditions and reduce the power used to acceptable levels.

    Right now I am trying to decide on Transfer box PTO or engine PTO and which pumps and motor coombo to go for.

    In some circumstances I believe drive assist helps. it allows you to help steer a bit and also can help avoiding digging down in soft conditions, allowing you to "float" better.

    For those that doesn't agree, the point of this post is not to argue over the possible merits of drive assista. If you don't agree with the possible merit, please just stay on topic if nothing else just to make sure the hydraulic part is understood.

    The vehicle is a RRC, V8, TF727, LT230, Volvo C303 portal axles, Super Swamper TSL/SX 38.5

    With a LT230 PTO the pumps will se the engine rpm less torque converter slip and initially the 2.45 first gear reduction in the TF727.

    For the sake of argument, let's put the engine rpm at 2000 to minimise the torque converter slip and have the pumps spin at about 800 rpm.

    The wheel will se a further reduction of 3.32 in the transfer box and 6 in the diffs, making them spin at about 40rpm.

    Correct?

    40rpm with 38.6 tires gives about 3m/revolution gives about 110m/min ground speed

    twin group 2 pumps at 27cc would output about 45l/min.

    Using a 100cc motor would give a winch drum rotation around 70 rpm and a line speed of 17-32m/min.

    A factor of 3-5 difference in speed between wheels and winch.

    The other option would be engine mounted pump. This would have to be crank driven as the power needed is too much for other solutions. I don't know if I have the space to fit the pump in front of the engine without moving the radiator.

    Pump would see the full 2000rpm, giving about 100 l/min, giving about 180 rpm and line speed of 40-80m/min.

    Somehow my calculations above doesn't feel right. I feel that I have too fast wheel movement for my rpms. Perhaps I'm right but I would like to have this confirmed.

    Thanks

    Tobias

    Alternator replacement V8 Serpentine 3.9 1997

    in Discovery Forum

    Posted

    Hello,

    I want to buy a new replacement alternator for my 1997 V8 Discovery.

    Original mount is AMR4247, 100A

    I can buy a Denso one at Paddocks for £142

    I can also buy a AMR2938 intended for a P38 at £78, not Denso, though.

    Since I have a winch fitted I think I will benefit from the slightly higher output of the P38 one...

    Will it fit straight on?

    Thanks

    Tobias

    Use crossmember as air tank?

    in International Forum

    Posted

    I have a small airtank from an old lorry tucked beside the frame rail on my portaled rrc back in sweden. As i looked underneath the disco the other days for about how much space i had to go shopping in the scrappers here for a tank i saw the crossmemberabd tought" why not?"

    I'll drill a small hole and apoly pressure to see what happens before i take any decisions...

    Thanks for the input.

    Tobias

    Use crossmember as air tank?

    in International Forum

    Posted

    Does anyone hav experience or input in using the round section crossmember in the rear of a 1997 Discovery chassis as an air tank?

    From a quick inspection it looks as if it is just welded to the fram rails, so if the welds are good it should hold air.

    Thanks

    Tobias

    Discovery 1 short rear half shaftbroken. Funny position?

    in International Forum

    Posted

    Thanks for the input. I changed the bearings, hub seal and halfshaft tonight. The bearings nuts and everything had surface rust, not on rotating surfaces but the others. Obvious sign of water entry at some point. Managed to clean up the stub axle decently and popped out the half shaft oil seal so i will notice if it holds the oil inside, which should mean it will hold the water out...

    Tobias

    post-945-0-34785300-1428967865_thumb.jpg

    post-945-0-79120900-1428967888_thumb.jpg

    Discovery 1 short rear half shaftbroken. Funny position?

    in International Forum

    Posted

    good morning

    Last saturday i set about to change the rear diff that i presumably broke on the trail on long friday.

    As i removed the short side half shaft i ended up with only the mushroom in my hand. The shaft remained in the axle tube. It has snapped close to the mushroom hat. I think this is a bit unusual, but i have never ever snapped half shafts before, only diffs. What do you think?

    I was under the impression they normally break close to the splines in the diff end.

    24-splines discovery 1 1997

    Tobias

    post-945-0-39386000-1428927948_thumb.jpg

    Rear a arm extension availability

    in International Forum

    Posted

    This looks doable. There is a local machineshop that produces lockers and will knock up half shafts for me. I guess with a ball joint and the old bracket to take measurements from he could knock up something similar but only 40-50mm longer than stock.

    Convert 1996 Disco V8 to cats+oxygen sensors

    in International Forum

    Posted

    Since the lambda value was 1.17 and acceptance limit is 0.97 to 1.03 it would not pass with just cats, it would need the O2-sensors as well. But they are also installed in the downpipes we have, so as long as I can splice them in and install a tune resistor, that part is OK.

    I have looked a little, comparing to another 1996 D1 parked at my place, but have so far not found the o2-sensor connectors.

    Will remove the ECU and check the loom to see if there are wires to the corresponding terminals, if so, I will give it a try.

    T

×
×
  • Create New...

Important Information

We use cookies to ensure you get the best experience. By using our website you agree to our Cookie Policy

  I accept