Improving engine efficiency?

[sven360]

When you lap the valves in.You should decoke the head.As I correctly stated earlier.

In fact, the decoke will be much more beneficial than valve lapping but do what you want.I,for one,am mortally offended by your cheek.

I demand satisfaction,sir.Pistols at dawn.

[valman]

When you lap the valves in.You should decoke the head.As I correctly stated earlier.

In fact, the decoke will be much more beneficial than valve lapping but do what you want.I,for one,am mortally offended by your cheek.

I demand satisfaction,sir.Pistols at dawn.

good stuff, worth doing on a 60k engine though? as i feel having one lady owner for 55k of that couldn't have done too much?

[sven360]

More so.

Doddering round @26mph in top is the worst you can do to any engine.

[classicswede]

Step 1 to good MPG from your engine is to make sure it is in tip top condition. This will invlove doing a compression test and if the compressions are low you will need to find out why and resolve the issues. This can often be tappets needing adjusting, valves not seating or worn bores/piston rings.
The air filter should be clean, plugs leads and all ignition system in good condition - just working is not good enough.
Set timing and fuel mixture correctly.

Check and reapair any worn componets in the suspension and drive line such as tight UJ's worn wheel bearings etc. Make sure tyres are inflated to correct pressure.

With the above done all should be as good as when it came out of the factory.

Now you want to improve on that.

Step one to improving your MPG is your driving style. To aid economic driving fitting a basic vacuum gauge will help but better still a trip computer is the best way to monitor your MPG.

To improve your engines efficiancy here are the things to think about

1) Burn the leanest fuel mixture you can without resulting in engine damage
2) Squeeze teh hell out of teh intake charge to make the most of it.
3) Let the exhaust gasses out with the least possible loading on the engine.


1) to burn a lean fuel mixture you will need to improve the ignition system to ignite the leaner mixture. The plug gaps want to be set wider for a stronger spark but you need more power to spark the plug. Electronic ignition with seperate coils is the ultimate way of doing this but a lot can be done with a distrubtor system with a higher power coil.

2) Compression. For best MPG you want to run the highest possible compression ratio you can. Best MPG is acheved at part throttle so the effective compression ratio is lower than for full throttle. You can increase the CR beyond what full throttle will take provided retarding the ignition will eliminate pinking under load. To take the CR this far you will need to run either a modded dizzy to retard dramaticaly under load or use a mapped system to do this idealy with a knock sensor. Again for the high CR you need a good strong spark.

3) Breathing. The idea here to keep the intake of the engine stock. Improvments on the intake will rarly ever improve teh MPG of any engine. On the other hand the engine has to labour to expell the wast gasses. If you give the exhaust side race head treatment you will reduce the amount of energy needed to expell the gasses. Combine this with a well flowed exhaust and away you go. You could even have a cam ground to give more exhaust duration to help even further.


That is a very quick and basic out line of what to but it should give you a good idea.

[Ride_on]

good imput, unlike the feckers above
would you recommend lapping on an engine thats done 60k?

Depends, an old 1.4 yes, anything else..no, unless the mixture has not been right.