Tuning a 3k for economy

[Z2TT]

bullshit.
that is totally wrong.
the timing mark is on the crankshaft pulley.
the other marks are on the timing chain case.
the ONLY way the timing mark is no longer accurate is if the crank pulley has rotated on the crankshaft.
that requires the key to have been munched, and that rarely rarely happens on K motors.

timing chain stretch etc might affect cam timing slightly, but cams, valves, lifters have little to no effect on the spark timing.

if anything, the dizzy rotor will change position relative to the cap, but the timing itself you will set, and the marks on the front are accurate.

i hate to say this, but if you don't know 100% what you are talking about, it is better not to post.

with 30yo motors, just note that when doing timing, the timing marks really dont apply anymore as they did when the engine was new, as the cams, valves, lifters etc are all get worn away. When doing timing you'll have to adjust it so it runs smooth.

No I didn't mean to say that the timing marks aren't accurate, e.g when set at 10 deg btdc thats not when it will fire --- I was not trying to say that. My wording suggest that though, so sorry.

I'm trying to say is on worn motors you only use the manufacturers specs as a rough guide, so if you set it to manufacturer specs, your motor wont always run great, so you may have to advance it a bit more, but it depends. Sorry to cause any confusion.

[ViPeR_NiPPleX]

Cush, aren't you happy with the current fuel economy it's getting now? Being a 3K it's not exactly going to throw fuel out the window unless something is horribly wrong. Give us an idea on how far you get to a full tank, provided your odometer is working.. and your speedo is accurate.

Stop being a pussy and just drive the thing with the loud pedal down

[Z2TT]

Ah some people just want to get the best fuel economy, every $ saved counts.
If your really concerned about fuel economy, don't drive the car as much, buy yourself a bike and save the Corolla for longer trips.

[Sam_Q]

given enough cash I woudl think the best way to get economy would to be to rebuild the motor to be tottaly fresh and with higher compression. Then fit a 4K injected manifold with a programable ecu. Of course the expense will never ever pay itself off in fuel saving but thats not what the question was, was it now?

[oldcorollas]

that depends what ECU and how much fuel it used before
EFi is a hell of a lot better for a modded K motor than a poorly tuned weber..

but a stock carby running on vapours, you won7t get a heap better

[hemi twofifteen turbo]

Don't forget the simple things like keeping your tyres up etc, often overlooked and can save a bunch. I think any money spent on improving the economy will take a long time to return but if you do a bit of highway driving the 5 speed box is probably the best option especially if you can get it cheap and fit it yourself. The other option is LPG, I had a 2t celica on LPG that was pretty good, but the lack of power got to me so it go 17 pounds through it.

[ViPeR_NiPPleX]

Cut the roof off. There is a ton of weight and structural rigidity stored in that puppy. Just think how much fuel those bastards with convertables are saving right now!...

But seriously. Firstly determine where the desired operating range of the engine is for the "crusing" you want to do. Something like final gear(4th/5th), determine the RPM of the engine at road speed you want be it 80kph/2000-2500rpm? and 100kph 2500-3000rpm and take the thing to a dyno. Get the operator to simulate the thing cruising at those speeds and play with the ignition to find what spark angle the most torque is generated at. If available to you, play with the camshaft timing/fuel jets (if carby)/etc. To go even further you could design custom exhaust and intake manifolds with tuned length runners to optimise the "powerband" for economy and be happy with all that effort.

Another fun thing to simulate is disabling two cylinders above a certain rpm to reduce fuel consumption. I've seen it done with a 5M-E with reasonable results.. however much easier to do with multipoint efi.

[celicapain]

Since people are being stupid about fuel economoy id love to see what you could get a K series in a little rolla to do with an economy biased build(nuthin major just comp, intake and exhaust flow optimisation) and a liquid lpg injection system.
7-8 litres per 100 @45cents a litre would be pretty bearable.
unfortunatly because the 4k is pretty light on fuel anyway any improvements are only going to be fractional unless you start spending some coin, which kinda distorts the economy equation.

[woggin]

how bout new spark plugs/leads/points, more efficient burn equals more power, thus less throttle needs to be used!!! could be something looking into!! new airfilter! ahhh.. cold air intake! thats all i can think of, probably only get minor gains, but 10 minor gains is still something big!!

[oldcorollas]

hmm, stock very tired K motor with 4 speed averaged 5L/100km from melbourne to sydney... in a KE1x

i spose you could do better... like 4.5 or 4L

but really, it is all in the driving style

[love ke70]

in a ke70 wagon that i had for 2 weeks before the rego ran out, 4k 4 speed which went well.
i got 7L/100km without trying, and seeing what the car could do.
iwould suggest that unless your economy is well farked, or your driving many many miles, chasing lower economies is probably going to be false economy...

[cambelt]

The original K and early 3K were the best on fuel out of all the K motors.
4,5 and 7K are drinkers.
Dave

[love ke70]

im sorry, but how is 7L/100km in a ke70 driven fairly hard a 'drinker' ?
what constitutes a drinker?

[cambelt]

A KE70 with a 4K driven fairly hard will use more than 7 LT per hundred , stop kidding yr self mate . That said they all vary a little bit but with over 200 K series cars experience i think i know a bit about them .
Dave

[love ke70]

im sorry, but im not kidding myself, they are real world figures, driving at 115 in 4th for my highway journeys, and enjoying the extra power of the 4k over my usual diesel daily drive i gave it plenty of welly, and they are the figures it returned.
my old 400,000km ke70 used to give 7.5 - 8 L/100 if driven responsibly