i2000 Posted May 3, 2011 Share Posted May 3, 2011 hi,i am restoring a 1985 manta 2.0 gte coupe with the original engine,is it safe to run it on unleaded.the previous owner has just told me he always used leaded or additives,i will be taking the head off anyway for an overhaul.thanks. Quote Link to comment Share on other sites More sharing options...
mantaboy89 Posted May 4, 2011 Share Posted May 4, 2011 Hi mine is an 85 gte and I ran it on unleaded no problem, I think if they are built after march 85 its ok, there a certain cut off date for leaded/unleaded heads, will try n find the info n let you know. Quote Link to comment Share on other sites More sharing options...
lepo5 Posted May 4, 2011 Share Posted May 4, 2011 Im sure it was around 85 the changes were made, but have a look at your cylinder head beside spark plug number 2 there should be a flat spot with a stamp on it stating either XR2 or P2E the P2E stamp means it is a head suitable for unleaded as it has the hardened valves etc, if it has a XR2 then it is not, and will probably need additives etc, P2E heads shold be readily available, but if your stuck, give me a shout and i'll see what i have. Quote Link to comment Share on other sites More sharing options...
Julian Posted May 4, 2011 Share Posted May 4, 2011 Im sure it was around 85 the changes were made, but have a look at your cylinder head beside spark plug number 2 there should be a flat spot with a stamp on it stating either XR2 or P2E the P2E stamp means it is a head suitable for unleaded as it has the hardened valves etc, if it has a XR2 then it is not, and will probably need additives etc, P2E heads shold be readily available, but if your stuck, give me a shout and i'll see what i have. When I took the head of my 1979 2.0 C I H in for uprating to unleaded, I was told that there is no problem with the valves, you only have to change the valve seat inserts, which they did at a cost of £160.00 that was five years ago, I was surprised as I thought that I would also need new valves. So that was good news! Quote Link to comment Share on other sites More sharing options...
manta400john Posted May 4, 2011 Share Posted May 4, 2011 Prior to engine number 20E-0354999 you'll need an additive. 2.0 models with engine numbers from 20E-0355000 can use unleaded petrol continully. Also retard the ignition timing by a few degrees. John. Quote Link to comment Share on other sites More sharing options...
monzta Posted May 4, 2011 Share Posted May 4, 2011 When I took the head of my 1979 2.0 C I H in for uprating to unleaded, I was told that there is no problem with the valves, you only have to change the valve seat inserts, which they did at a cost of £160.00 that was five years ago, I was surprised as I thought that I would also need new valves. So that was good news! That is correct. When you order a original head gasket set (full set of head gaskets) you can choose to make the unleaded conversion with this set changing the rubber inserts. They are lubricated by the additives in leaded fuel, and will crack and dry out when running unleaded over some years. If you plan to install another engine within the next year or two you should be just fine running unleaded fuel for that time. I have done this on several occasions when i knew i was going to change the engine anyways, and i have never had any of those engines ending up using oil. I did however buy a car where the owner had fuelled the car with unleaded for 5 years (92 octane) and that engine used alot of oil. But that was from a 5 year duration of time.. Quote Link to comment Share on other sites More sharing options...
i2000 Posted May 20, 2011 Author Share Posted May 20, 2011 thanks for your help.my engine number is pre 20E-0355000 so will look into having it converted. Quote Link to comment Share on other sites More sharing options...
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