An interesting aspect is that because the LS engines are so efficient they actually need less timing lead. I agree with Jim that there will be huge trends and differences between the iron head and alum engines. I’m sure Michael and TA already have some info.
Why is a flat top with larger chamber more desirable than a smaller chamber with dished piston? Lighter piston? It seems like a shallow chamber with a dished piston would actually have less valve shrouding.
Here is some info that I feel is concise and to the point: https://mondelloperformance.com/2018/03/piston-types/
Are you sure that's the link you meant to post? Here's a different one that could be more exact although it is aimed more at higher compression engines: http://blog.wiseco.com/examining-the-art-of-piston-crowns There is probably something out there aimed more towards street engines. But here's the main thing. Assuming that you have a set of aftermarket heads like the TA they are infinitely reusable. Seats and valve guides are replaceable so given normal wear and tear they could last indefinitely and be used on any number of short blocks. So it makes sense to me if you can set them up initially with something like 11:1 compression with a .040" head gasket and a flat top zero deck piston. Then as long as you don't want to go over that CR, building a new short block is easy. There might even be more choices in pistons, allowing the use of something off the shelf although I haven't looked at that. This would assume the larger chamber is even a possibility, I think the chamber volume would need to approach 70cc which is pretty large. That's just about double the volume of the TA-Rover heads and 15cc more than the new 350 heads. Looking at the TA-Rover heads I don't think this idea is really practical, but there might be a piston maker out there who could be talked into doing a mirror image dish. It would obviously be a custom and anybody buying such a piston would be smart to see if they could get a copy of the dish program file for safekeeping. That makes a good comparison of the advantages though. If it even were possible to enlarge the chamber that much, then there would be no need to even worry about things like matching the squish areas and such. Jim
