Running Of Unleaded Petrol??? (Leaded Engine)

[fragginfags]

I just found out my datsun 720, king cab's engine was designed for leaded fuel, which doesnt exsist anymore so im forced to use unleaded fuel, should i be running 95 octane or 98 octane? i read somewhere about hardened valve seats, but no idea if i have them :(, i also read that running unleade may cause the timing to be out which would explain why when i turn the car of, it shakes and keeps running for a few seconds, what are my options?

[datzenmike]

The 720 came out almost 10 years after leaded gas was removed from the market. If anything it's designed for non-leaded gas.

 

If your motor suffers from dieseling or 'run on' probably the idle cut solenoid isn't working and the idle has been turned up to high to compensate. Listen near the rear of the carb and have someone turn the ignition on, off, on, off, (not start) and you should hear a clicking sound.

[720life]

Maybe the Un part of his "unleaded fuel only" sticker under the gas gauge fell off lol jk

[datsunaholic]

Maryborough is is Queensland, Australia.  So the question is, what kind of engine is in it?  All NAPS-Z engines were designed for unleaded.  L-series all have hardened exhaust seats (folks complain the intake seats are too soft but the intake seats aren't the ones affected).  The ones that don't have hardened seats are J-series engines.  That's due to the cast iron heads... the head IS the seat.  Later on they put inserts in, but I don't know if Nissan ever put seat inserts in J-series heads.