318 ..For performance

[Richie]

How much reliable HP can a person get out of a 318. This one in my Dart isnt the original engine, the vin code says a 273 came with this car. I would like to get a 340 later one but for now I was thinking of getting the shop to get some more poop out of the 318. Thanks.

 

[rumblefish360]

Hey Richie; Reliable HP is a function of a few things including not beating the stones out of it. He he he he, but seriously, bolt on's can grab you an easy 350 hp without getting crazy.
If your going to rebuild the engine, 400 + hp is a snap. Just IMO at this level, the cam starts getting big and the power band starts higher that you'll be looking at higher stall speed converters and gears.
What is it your looking for out of the 318 now?
What are the rear gears and current tire size on the car?
Do you want to work with whats there now or start changing parts on the drive train?

 

[Richie]

Just something to cruise around the street with maybe 350 hp. But I'm going to get an 8 3/4 rear end too maybe 355s I dont want to be going down the highway burning too much gas. Do they make any kind of after market pistons for 318s? I had now idea you could get that much power out of a 318 LOL

 

[notorious318]

Hey, look at it this way, the Ford Mustang people boast big HP from a 5.0 which is a 302. I think the original Chevy Z28s had a 302 displacement also which Chevy guys like. Now I'm no expert on Ford or Chevy stuff but I think the 318 has good potential if it's warmed up with some good things. Who wouldn't want a 340? I have a 318 and I like it because it's already there. I also have a budget to think of right now and would rather hop mine up and see what happens. Have fun with it! - JD

 

[rumblefish360]

You can get a lot more power out of the 318. It just depends on how you want it, when it comes in and how much money you have to burn, er spend. LOL.
If you have a 8-1/4 rear, a Sure grip and gears is all you'll need unless that future 340 is well over 450 HP.
Keith Black makes flat top, zero deckable pistons for the 318. Federal Mougal also makes some. You'll just need to turn a few rocks for them.

 

[rumblefish360]

JD is right. We have superior equipment on a 18 cube advantage. Mopar fans are just used to messing with more cubes and forget about the lil'tricks that make the teen tick.

Pocket port & mill your current heads.
Shot for a 9-1, - 9.5-1 comp. ratio with a iron head at max. You can use a mild cam with that ratio for great streetabilty and mild(er) gear ratio's. Under 3.55.
For a cam with stock stall converter and numerically lower gear ratios than the targeted 3.55's, I'd look at someting like a Crane cam;
Advertsided duration; 272/284, .454-.480 on a 112 centerline.
At .050 it something like 218 and 224 I think.
A small 600 cfm 4bbl. on a performer intake or the one your going to use for the 340 later and headers will do very nice.
3.55's and a near stock tire diameter can step up in cam a bit.
(280* advertised)

 

[Dusterb318]

KB makes 2 off the shelf pistons for the 318.....a flat top with about 9.5:1 and aa dome top for the 302 and eddy heads that you end up with about 11.2:1 compression.....