its not a subject i fully understand myself (in fact i'd say infant to primary school level) but the total weight transfer is determined by the centre of gravity and the cars weight and track width, not the spring or dampers or roll bars. or rather 1 tonne car on mahogany springs will have same potential "weight transfer" as a 1 tonne car on air bags, or standard vauxhall springs and caravan helper spacers. the only choice with springs and roll bars is what and where that weight is resisted, and it has to be resisted. 4 tyres can resist lateral force of 500kg better than 1 tyre with 1250kg on it, this i know to be true.
roll vs no roll all depends if its doing something beneficial to the geometry when it happens. in the case of the astra that's a no from what folk have measured on the astra forum, in that picture of me behind the skyline, the outside front will have rolled into positive camber and negative caster, both are bad !
a car with a wheel in the air (b-child picture doesn't count as it has both ) usually indicates that it has run out of weight to transfer to the laden wheel, that's with regards the opposite side of axle (or diagonally when speaking as a whole car) if its cocking a wheel BEFORE the laden tyre (or corner of vehicle) has lost mechanical traction, then as above, its not loading that corner up to its maximum efficiency, in which case roll resistance/vertical spring rates are too soft.
yesterday at work i noticed a damp patch under the engine bay i popped the bonnet and saw the header tank was empty, so then started looking around for coolant leaks, but found none ! bit annoying as i thought i had isolated the "leak" at blyton, i.e the heater matrix !!
i topped the header tank up then started the engine to see if a bit of pressure would show it up, then noticed something splashing on my foot. Big sigh of relief when it turned out to be a massive diesel leak rather than the coolant hose or the water pump, phew !! plums! diesel was falling out of the high pressure pump about a drop a second.
the leak was coming out of this big nut, no idea what was behind it. i spent about an hour googling and trying to find out if the pump was gonna explode like dropping a cookoo clock off of a balcony if i undid mystery nut. turns out there's a plunger behind it and a weak spring, a hydraulic cross shaft for the governor
the other issue is that it was behind all this, and measured across the flats at "nothing in my tool box", ffs !
so after dropping the coolant, removing the radiator and the pointless inlet resonator (i mean lets not spoil such 80s diesel refinement with bit of induction noise) in granddads box of random i found a 3/4 whitworth socket which was almost a perfect fit, tentatively wound it out to find a simple O ring to blame !
replaced that with a puffy new one, wound it back in with some lube, no leaks !! not gonna say an easy fix as it took me half hour to get to it.
after that i stripped the centre console out to get access to the heater matrix, no doubt that leak!
i'd already managed to get this off of german ebay for not too terrible 65 quid, and it had also managed to get to blighty without spending a day in the back of a DHL van propping up a pallet of marmi grigio tiles. Unfortunately had to pack up for work but got as far as taking the heater hoses off the engine bay side, plus everything in the cabin removed up to the retaining bolts
i've been having a bit of trouble with cold starts, rough running and bad smoke. originally i blamed this on a partial miss fuel with petrol, however it carried on into the next fresh tank of diesel, and the one after that. it runs great after about 2 minutes, smoke stops. obviously poor cold start is glow plugs, but the black smoke gave me a curve ball for a couple weeks, enough to completely discount them. then i read on wednesday that knackered glow plugs COULD cause smoking too.
i spoke earlier in the thread about basic science of diesel engines, air alone is compressed by the piston, which heats it up. well when the engine is stone cold most of the heat from compressing air soaks into the cylinder walls and head, enough for the air temp to dip well below diesels auto ignition point. glow plugs are probes that stick into the precombustion chamber, basically a controlled short circuit they glow white hot and heat the air around the injector nozzle, giving it a little boost and away you go. theoretically you could start a diesel without them, but it would take some minutes churning away on the starter motor. And its obviously easier the higher the outside air temp.
found some tests on youtube that involve taking the plug out and measuring with a digital volt meter, set to ohms, between the body and the tip (green and red arrows below). With the meter set to 200 ohms (lowest setting) the plug should read under 1 ohm. my 2 centre plugs were off the scale even on 200,000 ohms. the upshot of that is they don't glow at all or would take minutes to start glowing and therefore patently useless
the purple wire here comes from a glow plug relay on the bulkhead, which i think is fed directly from the battery. the flat strip of copper joins 3 plugs in series then theres a piece of wire daisy chaining to the 4th.
12mm socket gets the plugs out of the head real easy. as above the coloured arrows show where to measure the plugs. 2 of mine were off the scale at 200,000 ohms, the other two still about 8 ohms, so on the turn. i got a new set of bosch plugs on ebay, 14.99 delivered so hopefully thats the end of it !
After the triumphant leak stopping in september the fuel injection pump sprang a brand new leak from the accelerator shaft at the top, literally 2 days later. After that i thought plums and carried on living my life. not sure whether its a protest to the petrol missfuel, or just what happens when you press a car into daily use thats been laid up for 8 years.
2 weeks ago i spotted something in the "you may also be interested in this...." thingy at the bottom of ebay. it was a new lucas DPC pump, but at just under 200 quid it was a no go, the land rover had just thrashed my bank account, again.
then a week later i got a notification from ebay saying the price had dropped on the pump to 125, which if i do say so myself is an absolute bargain for a lucas/delphi diesel fuel injection pump. so the pump is now mine ! this also signifies a commitment to keeping the car standard for the foreseeable future. its providing ultra reliable and ultra frugal daily transport since i bought it, as of right now the car has paid for itself in fuel savings (compared to if i had continued my previous petrol car)