Re: Proper gas for 374 engine

Posted by Owen_Dyneto On 2011/2/21 17:50:35

I run premium pump gasoline with the mandated 10% ethanol. No problems, but if I plan on a long, hard and high speed run, I add a bit of real tetraethyl lead just for a little extra protection of the exhaust valve seats. Aviation gasoline definately not required. But I'd recommend setting your ignition timing, with the grade of gasoline you intend to use, such that you have minimum spark knock which can, over the long haul, do severe damage to the pistons. You may find that setting your timing to 5-7 degrees BTDC is about correct, at least it is for my 56 Caribbean.