[DavidBoren]

Thank you for the input. I have heard that about iron heads making more power due to combustion chamber heat.

And given that this is a discussion of design theory, I see the inherent detriment of increasing stroke. The side loading and friction/heat increase presents a problem to be resolved, for sure. And is probably (obviously?) best left avoided.

In my particular case, I will have an oversized cooling system with electric water pump and fully boxed/ducted radiator, to handle the heat. And I am going to use the small bore block to capitalize on its thicker cylinder sleeves to address the side loading caused by the 4" stroke.

I also will be running an oil cooler, and I have a small quandary about oil squirters...

Are oil squirters piston coolers, or are they just oil heaters?

They use engine oil to cool the piston. Which puts the heat directly into the oil. Are the pistons cooled enough to really make a difference in detonation issues? Doesn't cooling the combustion chamber decrease power output (as discussed above with iron vs aluminum heads)? Doesn't squirting 75psi of oil UP at a piston that is traveling DOWN add resistance/drag that is otherwise not present?

Also, undersquare engines have better combustion due to small chambers, less surface area, blah blah blah. So if oil squirters do detract from the combustion efficiency, due to heat loss in the combustion chamber, this effect would be naturally counteracted by the undersquare small bore combustion efficiency.

If oil squirters are just to stem detonation, then the long rods inherent to an undersquare motor make them (oil squirts) unnecessary. As long rods slow the piston near top dead center, and naturally reduce detonation issues.

Said another way, do the characteristics of an undersquare motor counteract everything oil squirters are trying to accomplish? Or would the longer stroke, and the friction/heat that comes with it, be in a greater need for added piston cooling?