Perhaps it should be a Super-Duper 273 ?
The dual sparkplugs of a 5.7 V8 are such an advantage that engine should be the starting point.
(Since even the late dual sparkplug 4.7 have bad reputations I will not consider those.)
An air to fuel ratio of more than 20, perhaps even 25
can gain a lot,
and you “probably” need fuel injection to keep all 8 cylinders even.
Dodge Ram, or maybe Dodge Magnum station wagon?
Better aero of Magnum would help a lot.
I have the Dakota, use it a lot, it won't sell for much here (2wd) and it would be much harder to set engines and things in the bed when I go to the junk yard, machine shop and such...
I do have an eagle 5.7 I could swap some early 5.7 pistons in for a big compression bump, they are slightly taller and have a bigger dome that should not interfere with flame travel...I would love to have a hemi in it, I just think it would be a much bigger project than I want to do. It would require me to build motor mounts (don't know how) build headers maybe/probably (don't know how) building a wiring harness (could do it but I hate electrical) then I got to figure out how to get tach to work, CEL, kickdown...
I would also think a 273 would be better suited to this project but again I would have to build motor mounts and a crank sensor mount, buy a block, run a flat tappet cam or spend a pile on retro roller lifters if they are even currently available or run a flat tappet (not the end of the world) compression would be even harder to increase...
The question of compression limit in the 318 magnum is when you mill the heads much more than .030 you will end up with the valve poking below the surface and after about .060 you are gonna start getting too close to the seat it's elf. Also poking it below the surface means valve notches in the pistons witch gives the fuel and air a small place to hide from burning quickly. If I do this I will notch my stock pistons only as much as I absolutely have to for valve clearance, the valve notch in the kb167 (I ran them in the first MPG 318) is huge, nice for a big cam but will negate the compression I am after by milling it so much in the first place. I suppose I could turn the diameter of the valve down to match the seat instead of opening the seat to the valve... then I could probably safely mill them to .060, anyone know what size the chamber would be on a magnum if milled .060? Assuming I can get it down to 58 CC and .028 quench would only give me about 11 to 1 witch is pretty good in a normal build but I really want it very high so I can retard the cam to bleed pressure and take advantage of a dramatically increased expansion ratio.
