tryna get close to 400 hp...Wanna work out my 973 casting 318 heads

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eviper21

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I'm trying to pull maybe 350-400hp out of my 318.

I'm planning on KB flat tops to up the compression a bit but what should i do with the heads?

i know they're restrictive so im thinking i can have the shop mill it .050 and put bigger valves in it. Question is, do i go 1.88 or 2.02?? Then port match? Id try to find some 302s but my heads are brand new recon. so I know they're good

The cam i have is a Crane 272
http://www.summitracing.com/parts/CRN-15005/

.454 lift...i think that'll work out yea? Or should i sell it and go bigger?

anyways, any input would help out. These are my ideas, just wondering if anyone has different opinions on the set up other than going to a 360. lol

thanks
 
I think my 318 was about 330-340 horse, I used the 302 heads with stock valves and did some porting. I used domed pistons and had 11.5 compression with a comp xe-274s solid cam with .500 lift. I think you will need at least .500 lift to get to your hp goals, and it will take more rpm than a 360 to get 400 hp.
 
IMO, you won't get anywhere near 400hp with that camshaft.
 
If I were you, I would find a set of Magnum heads and the gear that goes with it. Then have them milled for the desired compression ratio. Then go with a good sized cam with at least .500 lift and .230 duration at .050. Also hedders and a mopar m1 single plane for the rpm. Probably a 750 cfm carb too.

Edit, I noticed the cam you have listed. That's the one in my 318 and it sucks.. Not big enough.
 
Look at the sticky of 1wild&crazyguy on porting 318 with head stock valves and valve job flows 215 cfms good for 400+hp.
 
Unless you are good a porting heads buying better ones will get you closer to your desired output. Since you are going with a flat top zero deck piston 360 heads would be a better choice. I ported a set of 318 heads for my dart and it took a long time and I removed a lot of material before I was happy with them. The same amount of work on a 360 head would yield a lot more flow. My motor is all stock besides the cam, ported heads and performer 318/360 with a thermoquad. If I had the flat tops you are running I would definitely go with at least J heads.
 
Yea didnt have much info on that cam, and i figured it was a decent stock upgrade. but i need it to be fairly streetable too. I like the chop but the car will see stop and go traffic so i need it to not almost die when im driving around the city lol.

I know 400hp is gonna take allot of work, more than i want to spend probably for a 318. However. id be very happy with 350-375 ish. Im sure i can do that with worked 973 heads no? Id really like to use these because theyre new.
 
I've always wanted to juice...maybe only 50-75 tho cuz I'm scared hahah. but my cousin ran 75 through a stock ford focus. ran 13 in the 1/4 ..not bad if you ask me
 
The only way to get that kind of hp out of a 318 is going to be to turn a lot of RPM (smaller displacement means more rpm for same horsepower).

To make that work you are going to need a lot of cam. To make that work you are going to need a lot of gear (and a high stall converter if its an automatic). And when you get all that going, it is going to be very short on low end torque, which is where all the "fun" in "fun to drive" comes from. It is not going to be very streetable by almost anyone's definition.

If you're going to put better pistons and deck the block, a 340/360 head would work a lot better than if you tried it with stock .100 in the hole pistons.

Your "good" castings wouldn't really offer any advantages expense-wise over something you find: 302s, etc. if you're looking to add springs, valves, valve job and milling. And for all that money you could probably get some LA-X or EQ magnum heads that will flow a ton more and already have hardened seat inserts (and then you would have cylinder heads for the bigger motor you will one day upgrade to). These heads also have much smaller than stock combustion chambers to build compression, and they are a favorable wedge style, rather than open.

ALL the power comes from the cylinder heads (and to a lesser degree the camshaft), that's the last place to skimp when trying to make horsepower.
 
Build for a powerband not some vague hp goal basically it seem you want a srong running but streetable 318. Build for idle-5500 if you do it right 350hp shouldn't be a problem, 9:1 high lift 268 cam, headers, etc... KB pistons zero deck and 360 heads will get you 9:1.
 
for the heads I'm thinking mill .03-.05... 1.88 valves (i think id loose way too much low end with anything bigger) and a home port match. The pistons KB167 flat tops..that should get me close to 9:1 compression no??

The cam I'm still not sure about. Something along these lines?? http://www.summitracing.com/parts/SUM-1798/

that should get me around 300+ with an RPM intake and headers ya think? Im trying to do more cam research but theres just allot that the cam effects. Kinda hard to keep up with
 
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