ScottC
Members-
Posts
67 -
Joined
-
Last visited
Content Type
Profiles
Forums
Events
Store
Gallery
Tutorials
Lexus Owners Club
Gold Membership Discounts
Lexus Owners Club Video
News & Articles
Everything posted by ScottC
-
Not wishing to throw a spanner in the works here, but a copper or silver cored plug has far better thermal conductivity and much lower electrical resistance than a platinum or iridium plug. So it should produce a better spark and wick more of the heat away from the combustion chamber. I went through all this a bit back when I got my LPG LS430 and I found quite a number of references to platinum/iridium plugs being created to meet the demands of extended service life in modern cars, rather than them being any better than 'traditional' plugs. I also found a number of references to platinum/iridium plugs being difficult/impossible to get out after extended mileages, so maybe a case there for using a plug that needs to be changed more frequently before it has a chance to get stuck. Scott Material Thermal Conductivity W/(m•K) Electrical Conductivity MS/m Silver 407 66 Copper 384 57 Gold 310 45 Iridium 147 18 Platinum 70 10 Nickel 59 10
-
Yes, however a quick 'google' reveals that the cylinder head temperature is significantly higher with LPG due to the quicker burn time of the gas. Running on petrol the cylinder temperature is reduced by the cooling effects of the petrol as it is injected. You don't get this with LPG as it is converted to a vapour in the vapouriser before it is injected. So it seems that the temperature around the spark plug will be much higher whilst the engine is running on LPG. Although LPG produces less total heat ( it has a lower calorific value) that heat is released in a shorter time. The reason for this is that LPG is a 'perfect' gas at ordinary atmospheric temperatures whilst petrol vapour is liquid that has been forced to vapourise. The cooling effect of liquid petrol droplets is not present with LPG and the total heat is released more quickly. A greater heat 'spike' is the result. The engine will run slightly hotter, although the difference may not be large enough to show on the temperature gauge. Only the cylinder head temperature (CHT) will increase significantly (although not enough to cause any problems). Most cars do not have a device for monitoring CHT (unlike aircraft). A typical car temp. gauge measures coolant temperature only, which is much more of a general picture. Leading on from that, it follows that an engine running on LPG will ' warm up ' more quickly than it would on petrol. Petrol consumption is extremely high when the engine is cold as a choke or excess fuel device (both giving a very rich mixture) must be used. LPG scores over petrol again, as this is not necessary. LPG does not need an artificially rich mixture and the engine warms (to its normal operating temperature, where it is most efficient) even more quickly as a result. LPG has a high octane rating (it tends to give less 'knock') and is more easily and thoroughly mixed with air. One of the results of this can be a quieter and smoother running engine. Scott
-
Hi Will When I went to look at my car the owner had run the battery flat by leaving the radio on whilst hoovering and cleaning it. A breakdown service had jump started it but connected the leads wrong and the car was quite poorly when we got there, wouldn't start at all but random bits still worked. Car was trailered to local garage who found a blown fuse, it took them a few days as it wasn't at all easy to locate. They had to order a replacement in as it was a special one. This is what the owner told us when we went back a week later to buy the car.......so there may be a fuse somewhere you have overlooked? If the car won't run over 2500 rpm and the OBD shows a fault code for the throttle actuator mechanism maybe you should sort that out first as the 2 things are probably related. Good luck Scott
-
Hi Piers Yes £500+ seems to be a starting point for professional rust treatment of a large car. I hadn't heard of Bilt Hamber so thanks for that, from their website they do a car underbody protection kit 2 x dynax-s50 750ml 1 x dynax-UB 750ml 1 x dynax-UC 750ml 1 x surfex HD 1L which might be the way to go for me.
-
Hi A friends 2005 GS300 is displaying the tire warning symbol and a 'system check' symbol. A previous tire warning was accompanied with a low pressure warning and the problem was indeed a deflated tyre. Handbook says the car can be driven and describes the fault as a problem with the electronics that monitor the tyre pressures, rather than a problem with tyre pressures. Any ideas? Scott
-
Hi So I read the owners handbook and it says to leave the ignition in the off position with the car jacked up. Once I had bled the brakes I ran the engine and pumped the brake pedal to make sure that with the servo in play the pedal was firm. The car was jacked up in the air with the engine running so I guess that the height sensors would think the front of the car was too high and deflated the front struts to compensate. Scott
-
Hi I changed the front discs and brake pads yesterday. I didn't quite finish as I ran out of daylight, I left the car on a jack on the passenger side. Today once it had stopped raining I finished the work and lower the car, it went right down to the ground and I couldn't get the jack out. The top of the tyre was buried in the wheel arch. Also on the drivers side. I started the car, the compressor came on and the drivers side pumped up to normal height but the passenger side did not raise at all. I jacked the passenger side to normal height to see if it would help. I ran the engine but the suspension just isn't there, when I lower the jack the car just goes down to the ground on the front passenger side. The car has been fine for the 30,000 miles I have done in it Any ideas please? Scott
-
Hi When I turned on my headlight today they didn't go through the usual self levelling routine. I park the car with a wall in front of me and usually when I turn on the headlights the headlight beam hits the wall at a low level and then after a second or so the beam rises up the wall a short distance. Alas no more.......any ideas please? Scott
-
I had my LS430 MOTed yesterday. All okay no advisories. Wandering around whilst the car was being tested I spotted on the forecourt of Lexus Cheltenham an LS400 for sale (£7,000.00). Maybe of interest if anyone is looking for something like this? Unusual to see an older vehicle like that in a main dealers. Scott
-
Hi 2005 LS430. As the car comes to a complete stop on the brakes there is a clunk from the drivers side. So to expand on that , the car has stopped moving and there is clunk as if some suspension component that is being loaded during braking is returning to it's normal position. Any ideas please before I take the wheel off? Cheers Scott