Originally Posted by
Hobbsy
I remember that Dar Zeelon had a fit when I told him that my Fox .74 ABC had no pinch, he swore that it would never be any good. I think that pinch is way over rated. My LA's don't have much of it either.
Without getting into plating 101, I've not heard or felt first hand a "tight" nickel plated liner. Brass and aluminum liners, yes. Car engines are notoriously tight and they're all ABC. I think in regard to the Foxes; perhaps the pistons are lapped closer to an optimum fit like the common ABN variety. Of course Foxes are test run at the factory so it's somewhat deceiving as to how they felt when totally unrun. Pinch isn't everything, I agree to a point however. Dub Jett said on one of his FAQ pages in regard to break-in and running his engines stated something to the tune of "ABC and AAC engines run better and produce more power when they are tight, and by the time there is no "pinch" left (bump at top dead center) the engine is starting to lose some of its power."
So I'm of the bias that a very low/no run time engine with an ABC or AAC cylinder should be snug. Mine have a pinch but they're easily turned over without a prop; glow plug or not. I'm sure it will run fine and last a long time but likely won't produce the power it's capable of if it had a tighter fit. I'm not complaining mind you. Just adding my thoughts and understandings albeit more limited than others here.
To be fair, your LA engines are in a different class compared to a Fox, IMO.