MGB GT....which petrol?

[amanda1uk]

Hi, I'm hoping to buy a 1972 MGB GT in a couple of days. It's a car I've always wanted and can't wait to pick it up. Just a couple of question. It has rostyle wheels, are they the correct ones, or did they come on later models?

Also,it has the original engine, and it's not been converted to run on unleaded. What is the best way of running it. There is a garage that sells four star not too far away. Would it be best to go there, or is unleaded with an additive just as good?

Many Thanks
Amanda

[falcemob]

I seem to remember the Rostyle wheels being standard on the early 70s MGB and Midgets, we had a 74 Midget with them fitted. As for the engine, is the 4 star you have seen leaded or just higher octane unleaded? I didn't think you could buy leaded petrol any more. If it is leaded then you don't need to fill up every time with it as the seats and guides will be coated with the lead substance for a good few thousand miles after a few tank fulls. In any case I wouldn't think it would be overly expensive to get a lead free head fitted if you realy love the car.

[amanda1uk]

falcemob said:

I seem to remember the Rostyle wheels being standard on the early 70s MGB and Midgets, we had a 74 Midget with them fitted. As for the engine, is the 4 star you have seen leaded or just higher octane unleaded? I didn't think you could buy leaded petrol any more. If it is leaded then you don't need to fill up every time with it as the seats and guides will be coated with the lead substance for a good few thousand miles after a few tank fulls. In any case I wouldn't think it would be overly expensive to get a lead free head fitted if you realy love the car.

Hi,

Thanks for that.
Yes, the garage near me is one of the few places in the country that's registered to sell four star. Apparently they get a delivery every alternate Tuesday, and it lasts for about three days! I'll consider the lead-free head option as well.

A

[wildoliver]

Rostyles = correct.

Unleaded fuel without additive = perfectly fine. If it pinks retard ignition slightly or use super. 4 star is also fine.

[wildoliver]

By the way where are you in UK there are only a handful of 4 star sellers in UK and one is near me. (It apparently isn't real 4 star by the way.)

[SB - Nigel]

wildoliver said:

Rostyles = correct.

Unleaded fuel without additive = perfectly fine. If it pinks retard ignition slightly or use super. 4 star is also fine.

On the button as usual

I would (as usual) recommend Tesco 99 (octane) as it's a good price and 99 instead of the usual 97 octane of Super (98 for Shell V-Power IIRC)

Don't bother with octane booster (unless you're going to put in 2 or 3 times what's suggested on the bottle) as they are expensive and don't seem to boost octane

Join the MG Owners Club it's only £5 for life (you don't have to subscribe to the monthly magazine if you don't want to) and buy an Owners Handbook (£6?) for your year of car and most information you need will be in it

Get the car fully and properly serviced and DO NOT spend any money on "upgrades" or fancy bits until you've owned and regularly driven the car for nine months

[wadgebeast]

Run it on standard unleaded - it takes years before the valves show any sign of harm and then it's relatively cheap to put an unleaded head on.

My car came with an unleaded head, but never required much in the way of adjustments to run the fuel.

[wildoliver]

See my thread on octane boosters.

[bigbadbikercats]

My take on this:

I've got a 1976 Triumph T160 Trident motorcycle which was a bit of a hot rod in it's day, was officially leaded 4-star petrol only and doesn't (as far as I'm aware) have hardened valve guides/seats. We've got a 4* stockist locally (Hurrah for Bayford Thrust!) but for the last three years or so it's run largely on supermarket Super Unleaded with a tank of leaded 4* just every now and then with no obvious evidence of valve seat recession (clearances have stayed as stable as you can reasonably expect from an old pushrod Triumph!) or other obvious ill effects.

I have a suspicion that the effect is largely psychological and has less to do with the bike than me but if I'm using the bike hard (say a long fast run with more modern bikes or a track day) it seems to run better (smoother, more responsive, somehow crisper sounding) on 4* than SUL. I do like to have 4* in the bike if I'm going to be leaving it for a while though as it seems less prone to gum up the carbs or "go off" as SUL seems to do when it's left for a while - I think the volatile fractions and additives used to raise the octane rating evaporate and what's left behind isn't terribly nice.

--
JG

[SB - Nigel]

(I did add below to my post but lost it when I closed the page by mistake)

I'm told the local 4* selling garage sells it at £1.50/litre already where as Tesco 99 is about £1.15/litre at the moment