Search the maintenance guides for answers to 99.999% of Omega questions
Its a pressurised system...remove the water cap of any Omega when up to temperature and the coolant gushes out...
QuoteQuoteMartin, what is it that you do, with keys?
One of my Omega keys is fine - but the other one feels like there's no travel in the buttons, and it doesn't work.
Hi James,
Pleased to hear the old girl is running well.
The switches in the Vauxhall key fobs have tiny rubber buttons on them, (which are pressed via the buttons on the outer casing). These seem to go soft with time, so whilst the electronics still work, the buttons need to be pressed harder and harder to lock or unlock the car.
The lock button usually goes first because it is pressed more often than the others.
If you can find someone to replace the switches the key fobs should work fine.
You will notice that one of your keys is slightly different, and newer than the other. For some reason when I needed to replace they key they found there was a problem with the alarm, and couldn't program the new key until a new one was fitted.
NN
Nigel! Great to hear from you
The old girl is running more than well, she is as smooth as silk, a real pleasure to drive - and not a sniff of coolant loss
Martin, what is it that you do, with keys?
One of my Omega keys is fine - but the other one feels like there's no travel in the buttons, and it doesn't work.
QuoteQuoteQuote
Any port "polishing" i've seen has been done across the flow as opposed to with the flow. Porting/gas flowing or shaping of the ports them selves is, i beleive, something of a black art. Getting each inlet port to flow exactly the same and improve the basic design. When talking in general terms of course, i've no direct experience with it.
Specifically with the omega, re shaping, i guess we are simply talking about matching inlet mating surface faces to the plastic inlet(and inlet manifold?) and removing lips or edges along with a general clean up and polish as the inlet is not restrictive as such....?
I mentioned 24 ports earlier, but are we just talking inlet? Is there much to be done with exhaust ports?
Exhaust Ports, No, (apart from deburring), Exhaust Manifold, maybe, to improve any retrictions or burring, but dont port the head to match the Exhaust diamiter, most Exhaust / Gaskets are larger than the Head port, this ridge gives a mini Dam effect allowing any Exhaust back presure gas to be restrictive towards the Head.
Port polishing is usually across the flow because that is the only way you can get a tool (or your finger) in the hole to do it!
The objective when porting road car engines should be to make it how the designer intended, by smoothing the ports, removing obstructions, and generally helping gas to get in, and out of the engine.
Radical porting needs skill and a sound understanding of engineering, (I'm talking about inlet tract and exhaust system design here), which is much more involved than simply providing large diameter pipes. Modern car designers are very clever people, but they have to work with cost constraints, and within production line schedules.
Port smoothing takes time, and time is money; although in fairness, most modern engines are very well put together. Whatever you do though, never ever think that the designer didn’t know what he or she was doing. They do know what they are doing, and everything they do is done for a reason!
Radical porting may provide an increase in peak power output, (probably at higher RPM than is desired), but will almost certainly reduce torque at lower engine speeds, which is far from ideal in a two ton car.
Turbo-charging (or to give it it’s correct title, turbo-supercharging) tends to be a more popular route to increasing power output nowadays because it provides increased torque across the rev range, provides greater tractability, and doesn't need as much brain power to understand.
NN
Fit adjustable bottom pulley to sort the timing perhaps?
Must be a way to match the inlet wedge to the new head position, can the porting process take out the difference? Struggling to visualise it, been a while since i was in there.
QuoteI should have mentioned yesterday -
The ports should be smoothed, but not polished, and finished with very fine (1,000 or 2,000 grit) wet or dry with a bit of light oil on it.
Polishing creates turbulence, whereas a smooth surface encourages laminar flow (= more inlet charge).
The key objective here is to smooth the inlet tract, so any gaskets should be trimmed back, and inlet ducts aligned with the inlet ports. This might mean ADDING material such as Devcon, rather than cutting it away.
The idea here is to assemble the engine exactly as the designer intended (AKA 'Blueprinting'), rather than how the assembly line does it.
If you are really keen, the compression ratios of all six cylinders should be matched (by measuring head capacity at TDC), and skimming a fraction off of the piston crowns as required.
You might also check the 'squish band' around the periphery of each piston, using a piece of solder to measure the gap at TDC. Anything more than 25 thou encourages detonation and pre - ignition, but most assembly lines work to much wider clearances for safety. Don’t forget to check the gap between the valves (when fully open) and the piston crowns at TDC too.
Most petrol engines will safely run with much higher compression ratios (= more power for the same amount of fuel) if the squish band is correct.
Many competition engines are blueprinted, rather than 'tuned', as this provides greater power and economy with better reliability. The difficulty is that production lines simply don't allow for this kind of assembly.
NN
On my Sunbeam I had 60 thou machined off the head - in fact it right up to the edge of the plug thread.
I considered a head skim on the 2.6 but that was too difficult being both V and over head cam
I need to go and get some tools for porting my V6 heads. Anyone got any ideas what/where?
TM is very useful for motorway driving, but not much use on other roads where coverage is limited. The red light also comes on if you are within range of a holdup, and pressing the button will provide a rundown, even if you are travelling in the opposite direction. Clever system for it's time.
I also found it useful on occasions when I didn't quite know where I was, as pushing the button provided an announcent of the road number, and 'traffic flowing freely'.
I haven't renewed mine for a while, and she only speaks if I switch the engine off and on again quickly for some reason.
You can shut her up by pressing and holding the button in a certain way. (Read the book). There is no need to cut any wires.
NN
