Building up a 318

Has anyone ever built up a 318 to make good power? Is it even possible?

I picked up a 360 for my Coronet that is a '75 block with magnum heads. I was curious if one could build up a 318 to make the same kind of power.

Opinions?

Let the debate begin!

I have been looking at that idea very carefully. A 318 with a .030 overbore and a new Mopar 4" cast or forged crank will make 390" and still look like a 318. Says so right on the side of the block! You can use standard length rods and special pistons. You don't need bigger heads or carbs to make great torque and it all looks so innocent!!

I am making 450 HP with a 5.2 (318) magnum stroked to 390. Very strong engine.

No debate is necessary. OF COURSE a 318 can be built to make power. DUH!

There are a few "400 hp 318" stories floating around, backed by dyno data.

Like any other engine it boils down to cubic inches, rpm, cylinder head airflow, and HP/cubic inch.

Getting to 1 hp/cubic inch doesn't seem to be a challenge any more, and a 360-headed or Magnum-headed 318 should see that easily.

It is also easy, nowadays, to build a 390+ cubic inch 318 block and one hp/cubic inch on it will be nearly 400 hp. You do need a head that will flow around 200 cfm tomake 400 hp, but that's doable with stock 360 or Mag heads with a little cleanup and a decent valve job.

Now we jump to the 500-hp 318. That's 1.57 hp/cubic inch, can be done with a 250 cfm head and a decent cam, but it's going to have driveability issues because you have to reallly wind the engine up to get enough airflow to make the power. The same heads on a 392 stroker 318 block will make 500 hp much more easily because it's only 1.28 hp/cubic inch.

Then there's supercharging with either a mechanically driven or turbo driven 'charger. That should get you to 600 hp at which point the block becomes the issue.

Of course nitrous is the easiest and cheapest way and Car Craft a few years ago hit a stock high mileage 318 with a big nitrous shot, made surp[rising power with stock internals before finally going South.

There is nothing inherently good or bad about a 318, it responds like any other engine of its size to head flow, rpm, cam timing and increasing the size either by stroking, super/turbocharging or NOS.

R.

Yes to both questions. That said the only good reason I can see to do so is the greater availability of 318 blocks. Since 360's are still fairly abundant I can't think of any good reason not to go with the bigger bore engine. The 18* small block heads have less of a shrouding issue than many other inline valve heads, but bore size does still matter. Still it can be done, just look at GM's LS1. It has the same 3.91 bore size as the 318.

And, so does the 5.7 Hemi, well almost.

R.

Yes, but the Hemi isn't an inline valve head either. Opposed or canted valve heads [ 2,3 or 4 ] regardless of cam location don't suffer the same degree of shrouding problems as inline valve heads. It's no coincidence that all the NASCAR Cup engines are a splayed or canted valve design.

I agree, go for 360. The only reason I did a 5.2 is that I found a 1995 5.2 magnum out of a wrecked dakota, with a 518 trans for $250. I sold the trans for $250. Should of kept the od trans. I would build a magnum 318 before I would build a LA 318.

You can do it for a budget build. Budget builds is what gives me the most pleasure with motoring, and if somethnings goes wrong, then so be it...
I made a well running 318 once with forged 11:1 pistons, 273 ported heads, cam, intake and headers, and it went really well with a 4 speed in an Aspen. Then my son fried the engine in a heavy burnout that caused engine overheating, and I took the parts out, and bored another block, put the parts into it + new rings/bearings and went on again....
He abused it again running drifting on a track, and I did not dismantle it, but this time installed a 340 TA W2 engine in the drifting Aspen, and fixed all the cooling issues. Another world of power, but not the same pleasure, and more preventive maintenance to avoid damage.
So I would say: Build a budget (with used old school parts) 318 for fun! My

Interesting numbers from a 318, but to get those kind of numbers seems like it will be a lot of $$. Since the 360 already has been built up a bit, I'll go with it and save the 318 in case someone would want to put it back in sometime down the road.