The 'E' Type Forum

The engine in my '66 FHC was showing signs of needing a rebuild. Low compression in one cylinder, smoking, and most damning of all it would barely register above 20 psi oil pressure. After confirming the low oil pressure with an external gauge I decided it was time. The car has been such a pleasure to drive over the last year that I've decided it's a keeper, so I'm going to do this my way. I enjoy running my cars hard and in the upper rpm range, so I've already descended pretty far down the slippery slope of "While the engine's out...". I'm sending it to Bill Terry of TT Engines. Bill builds the engines for the Predator Jags that compete well in vintage racing here in the states. I've asked him to build me what will essentially be a 7,100 race engine for the street that runs on our 93 octane and with a slightly less aggressive cam. Some details are; Balanced 10:1 forged pistons, balanced forged rods, billet competition crank, ARP studs and rod bolts. big valves, ported and polished heads, 48mm Webers and headers. It will be tuned on Bill's dyno.

I'm looking forward to getting my cat back with its claws sharpened!



https://www.ttraceengines.com/

I'm afraid that 93 octane and a 10:1 static nominal CR do not go together. Even at 9:1 with modern fuels, pinking is at best a nuisance and at worst can be a destroyer. It is often not the pinking you can hear which is very destructive, but the higher speed detonation which you cannot hear but which can burn holes in pistons in a matter of seconds. Do you really want 10:1 ?

I'm trusting my engine builder on this, he's been building high-performance E-Type engines for a long time and has done quite a few to this specification with good results. Incidentally, 93 is our highest octane available for highway use here in the US where we use the (RON+MON)/2 method. I think that is about equivalent to 98 octane (RON) as measured in the UK.