This is what the sticky label covering the "True Chrome ABC" on my AP Wasp box says.
AP must have changed the way they make either the piston or the cylinder.
Googling Hypereutectic Alminal comes up with Hypereutectic Aluminum which is an alloy with a high percentage of silicon dissolved in it, making for a glass hard surface.
Googling Alminal results in not much info but there is an alloy of Aluminum (Aluminum, copper & Cadmium) Alminal 500 made by Almin Ltd. in England.
Does anyone have any details as to what is going on here? Is Alminal a Chinglish misprint or are they using the Al,Cu,Cd alloy in some way?

On another topic and in response to Dan who wanted to know what plane I plan on putting my new Wasp on, I don't rightly know. I usually like to build all the old 1/2 A planes that I couldn't afford as a youth and power them with period engines. This is a modern engine and needs a plane of modern design. Any suggestions? Otherwise, I may be forced to design my own... I could call it the "Hypereutectic Alminal" or "Hyper Al" for short, now how's that for a handle!

Orv.

Typo, I think. Hypereutectic aluminium is the usual choice for ABC engines and I suspect the Wasp is no different.

I've been trying to sell my Wasp, but no takers here. I might just have to put it to use instead!

Orv--I'm putting mine on a Brodak Baby Flite Streak.  That SkyWriter looks good also !

Check the crank fit.  If you are "lucky" it is tight.  I have found 2 tight compared to 1 loose.  Tight can be fixed!  And they took back the loose one and replaced it no problem!  I LOVE this engine!!! (own 15 of them! Have only run 9 so far, but generally, the fits work just fine)

Tight - lower rpm, burned plugs, hot running.  When you disassemble the engine and clean it totally dry, the crank is still not free in the crankcase.

Loose - wobble in the shaft, blowing fuel out the nose of the engine

Just right -  totally clean and dry, spinning the crankshaft in the case will produce a couple or more rotations, and there is no noticeable fuel blowing out the front end when running.

On ONLY the AP Wasp, you can do a conventional lapping procedure on the crankshaft.  No other small engine I know of has a bronze bushed shaft bearing!  I still polish in my cranks, rather than lapping them.

Lapping an aluminum crankcase will leave grit embedded in the case material, and induce premature wear!  Oil-wet sand, polish and then clean the crank outside the case, and then recheck the fit.

I have detailed this procedure elsewhere, and you can find it with a search.