my 1000\1200 workshop manual tells me that the 1000 has slightly more raito that the 1200... Ill read it up tomorra

I thought they were 1.5, but that's probably an approximation of 1.44

Same thing applies to the L series, factory says 1.5, but in reality 1.55 is closer to the mark.

Quote:only one way to find out - trial assembly and plasticine/play-dough (or whatever). anything less than .080" clearance for the inlet or .100" exhaust will require notching

The 1999 Nissan Motorsports catalog says that the stock rocker arm ratio on all A series engines is 1.44:1

I am thinking about getting some roller rockers as well, but I'm not sure which ratio to go for. I have a A15 with stock pistons/comp. ratio, unmilled head, and the cam has .414" lift will the 1.65 ratio rockers make the valves hit the pistons??? Anyone???

So the stock ratio is 1.25 ?
I always wondered this.
I have 1.65:1 rollers. I was wondering what the difference was.

Not 100%, but believe they are all the same 1.25:1.
I have roller rockers in my A12A with a rocker ratio of 1.5:1 which effectively gives more lift & duration to the cam grin - probably an advantage in a turbo engine (but I'm not a mechanic).

Does anybody now what rockerarm ratio the A14 and A15 engines has??