90 defender 2.5 petrol,pinking

Hi to everybody.I have a 1989 90 2.5 petrol,has anybody got any answers to running these on unleaded petrol.The head has had inserts fitted to the valve seats. Have retarded the timing that far to stop pinking then, thing is worse than driving a tractor ie 15 to 20 mph up a bank.The hill is not that steep.Got lead substitute in petrol as well. Engine has got new carb,electronic distributor,plugs,leads,coil, fuel tank plus pump,filters,fuel lines. Sadly have forgotten most of the things we use to do to these engines apart from dropping a v8 or a 200 tdi in.Am planning a 200 tdi but not for 18 months or so.
Any sugestions would be most helpful.
Cheers Philip. PS happy new year to all

run it on ordinary petrol and don't worry about the valves. by the time it's a problem you'll have got ya 200Tdi. & if you haven't and the head fooks up completely what does a 2nd hand head or even a complete engine off fleabay or a forum cost yu.

^^ what he said. girlfriends series has a 2.5 in and we just run it on unleaded and it goes really well, much more torque than a 2.25. thirsty though!
will be fitting my old 200 soon though, when i have some spare time that is!

Thanks all thought as much to be honest these old girls like there four star sadly and you are right thirsty too.

Ran my old petrol SWB IIA on unleaded for 12 years with no probs.
When I sold it the engine was as sweet as a nut.
Should have held on to it with hindsight.
Sounds like there may be something else causing the pinking.
Have you got the right plugs in because if you have plugs that run hot they can cause pre ignition. May just need a de-carb.

The plugs am running in it at the moment are NGK BP6ES on second set. Other ones are champion RN9YCC which you dont see on the selfs anymore.Autodata cd,s say these are the ones,spose its trial and error and try some other ones

i,ll agree with wot shifty sed about his series an me dads 90 runs sweet on unleaded stuff anurl

If you're having to back off the timing so much that it lacks power then something else aint right. I'm assuming the cam is timed correctly???
My IIA had an adjuster on the dizzy and with the engine warm I used to keep ADVANCING the timing leaving the throttle alone until I got to the point that the idle would increase as much as possible. If you go to far it will start to slow down again.
Then I'd stop the engine and see if it would start again. If you go to far on the dizzy it will either spit back through the carb or try to fire the engine the wrong way against the starter.
Back off the timing a tad until you get max idle but it will still start when hot.
Take it for a run and get into top gear at about 20mph and floor the throttle.
If it still pinks back it off a tad more and try again.
If your plugs, points, leads, etc are in good order you should not be far off.
Not having driven a petrol motor for many years I'm going from memory but I'm pretty sure it will get you in roughly the right place.
We only needed to retard timing for ****e 2* petrol (not available these days) or when we used to mix parafin and petrol to make it go further.

Have tried the timing bit it does not realy matter where you put it really.Must agree its **** petrol. Have had head off 6 months ago and it was pretty clean I must admit as far as carbon build up is.Only other thing I can think off is it has got a 2.25 head on it as the old lady that it belonged too could not take it off the road at the time so an old 2.25 head was converted valve seats.valves and guides etc. Ignition is electronic so no points sadly,valve clearances are all ok as well.Got me beat must admit

If it pinks everywhere from cold on new plugs its prolly simply got too much compression. Maybe the 2.25 head is the cause.

Other thought was the carb, but you say that's new..could be worth cleaning in in case there's a blocked jet somewhere.

Might be worth a CO2 test..that often tells you about the state of the fuel/air ratio.