D it's been 15 years or so but the D-Sports Racer guys told me that for the 1300cc engine with E-series head made 165hp at 8600rpm and when revved to 9800 185hp. Also when revving to 9800 they started having valve train issues, mostly with valve springs.

I suppose an A15 with the E15ET head might make another 15-20hp

someone from the US was claiming on here 48mm inlet vales where possible on the E series head due to the hemi chamber angles?!! and much more hp than I was claiming with the A15 bottom. I guess capacity and revs fills that chamber better?

D unfortunately I do not know what valves they were running in the motors I gave the power figures for.

The valves sit pretty offset on the chambers but I found it hard to imagine
48mm inlet valves in a 79mm A15 bore but I guess with some nothing its possible
but thats almost 6mm larger than a 42mm inlet valve which has been fitted to an A.
Yet at 9800rpm Im sure the 16v or even Ga16i 3 valves chambers put out more hp
as the 3 valve head runs finger followers the 4v are direct cam actuation but
maybe the 8v heads have nice torque band or 16v is not allowed.

Just measured my E16 head and it has 37mm inlets. 48mm seems like a hell of a stretch!

37mm inlets, thats a nice starting point! 48mm he wrote on this site in one of the threads, cant remember who but looking at the alfa hemi chambers they could go to 48mm but much bigger bore. I wonder what the original valve sizes are for the e16 or e15et head? http://machineworldny.com/images/products/NI33M-4.jpg

37mm is the standard A15 intake valve size. While the E16 is the same size, the crossflow design of the E flows more air. Most E15 have 41mm valves as do some E16. A semi-hemi (canted-valve crossflow) should do even better

like this DD, its more like the Hemi 2 by Chrysler corp
but missing the vital second spark plug which is proven
to improve combustion quite a bit as Alfa has done.

http://oi39.tinypic.com/2075ij7.jpg

Been online gleaning as much information from images and videos of cnc work on cylinder heads.

I am drawing up as much visual input to see how I am going to approach the new head. I think its starting to bother my wife how glued to the phone or computer I have become.

Yes, Nissan used two sparkplugs per cylinder in the 1981 NAPS-X engine and got 46 mpg highway/32 mpg city in the Stanza. Pity they didn't do it for the E engine which came out the same time