TF's on a 318 ???? Oops, another 318 thread...

It's easier to look at ford 289/302/351/400 or even chev 302/327/350 Since they all have the same bore and flow potainal so same heads on each will flow the same.
Quick little math trick with 4" bore V8 is the stroke is just basically displacement minus 2, so 302=3.00 327=3.25 ford 400 is actually a 402=4.00 etc..

Some will disagree with me on this is displacement doesn't make HP, But displacement of a NA engine is mainly how torque is produced, torque is basically a snap shot of one power stroke and hp is all those power strokes added aka rpm. Why I say torque is basically one power stroke is soon as the crank moves were not talking about torque anymore but power, It's impossible to separate torque and rpm in a running engine. So it's easier to look at torque as one power stroke and why displacement is a large part of that is more fuel air charge, VE% of the displacement is gonna produce more pressure on pistons during combustion also you got cr and chamber design etc.. but those are like likely be same or similar between similar built engines especially when talking same family of engines. So displacement is king? yes/no it's actually bore is king especially if you don't care at what rpm your engine makes power. EG. say you got a 200 and 400 cid engine both making 1:1 torque:cid so the 400 has twice the torque but generally the 200 can spin twice as high if they got the same bore. So they will have the same power cause 400 will make 400 lbs ft in one revolution but the 200 will two revolutions in the same period of time so 200 lbs ft + 200 lbs ft = 400 lbs ft bascally so same hp, that's why engines hp numbers are more valuable they not only count for the torque but the rpm as well.

So if you did a Chev 302/327/350 with same heads cam cr etc.. the powerband should just move up in rpm and make similar hp, problem is even thought the top end is the same including bore, cam timing and runner length port size shapes etc.. will favor different rpm, bore stroke and rod ratios etc.. It's hard to impossible do apple to apple comparison when it comes to different displacements.

Now take 273/318/340/360 all have different bores as well as displacement, take 273/318/340 since they all have same stroke, they all have the same rpm ability with right top end, so the smaller ones won't be able to out rpm the larger to make up the displacement difference eg say there limit is 7250 rpm then 340 is gonna make the most power at 7250 rpm and 273 will make least at 7250 rpm but the 273 will need a lot less head flow to achieve it. Now 302/327/350 Chev all will have the same air flow capability cause of bore and parts, so stroke becomes limiting factor says the all have similar strength bottom end aka piston speed, says max piston speed 4000 fpm 302 hits 8000 rpm, a 327=7385 rpm, 350=6897 rpm, You will displace the same amount of fuel and air at those rpm 699 cfm so all would or should have same potential of hp. But they all have different bore stroke rod ratios friction losses etc.. and how heads cam etc.. will work with the different displacements and ratios but theoretically they have the same potential.


The 302/327/350 in this all make basically the same hp but at different rpm but the two different ls engine didn't mix bag of outcome.



But saying all that if the average 340/360 guy makes 350-450 hp and you build a 475 hp 318 setup to take full advantage of it for a quarter mile that you will beat all them and even higher hp cars if there not setup right, this would be if similar weight.


like this….

Iron-Headed Mopar 318 Magnum Engine- Popular Hot Rodding Magazine

went 11.60’s at 3400 pounds in my previous car with a smaller cam, stock fan and WP
At 12 to 1 with a roller at 3000 pounds, 10’s would have been easy. I shifted it at 6200 rpm