heads... exhaust... intake

-
D

DdgeDartboi

the beast
Joined
Jan 31, 2006
Messages
71
Reaction score
0
Location
Georgia
ok well im here for help as usual.... im just wondering what the advantages and disadvantages of putting 360 heads , exhaust manifolds and intcke manifold on a 318 are... can i get better performance out of the 360 heads on my 318.... i know i can get just as good flow and better ground clearance out of the 360 exhaust manifolds and he says i can get just as much performance out of the heads as i can with doing alot of work to some 318 heads... if you guys could just help me out here it would be much appreciated... the 318 is standard bore.. has had no work on the block... has a mild cam running a holley 650 and thats about it right now... please just let me know about this its much appreciated

BTW i have read alot of posts on here about why the 318 and not the 340 or 360.... please don't start that crap on my post... i have my 318 because i don't want to be like everyone else... and thats all there is to it... im just trying to pull as much out of my teen as i can

Toby
 
Alrighty well. The 360 manifolds i think 360 heads have bigger exh ports than a 318? but im not sure. If so then they would be a little better to use than the stockers. As far as running the heads, 360 heads are a pretty common thing for 318 upgrades, 302 and magnum heads as well. Downside to the 360 heads is that if you bolt them on, you will have low compression ratio. They will need milling to raise the compression ratio back up.

I have stock, milled j-heads on mine. 284rwhp S.A.E
 
thanks for the reply goody.. would still love more feedback from lots of other people... love to hear the different sides of everything.... im really hoping these things will help... mainly because with those hooker headers right now im bottoming out alot due to ground clearance and it sucks
 
headers are always an issue. I used to have issues before, but for some reason not in a long time. I do have taller tires than stock up front, and firmer shocks, might have to do with it. But i've come to drive a little differently i guess as far as bumps and dips, and E & Abody headers interchange.

the 360 will also have bigger intake ports. (if you dont have one, i got one you can have for the cost of shipping if you want it. just a factory 360 4bbl, nothing fancy).

-Mike

my '318cu 200hp' with a eddie intake and the 'performer rpm' ground off it can be a little decieving. >:D

valve1.jpg
 
thats a good looking teen..... im guessing that is ram air tubes... where do you have the inlets at... in the grille? or where
 
If you posted this 5 years ago, you'd get "run them, they will work fine". I've bolted them on and added a cam and they worked fine to me. I dont think any 360 manifolds will fit an A body. They dump right at the steering shaft I think. If I had to do them same stuff over again, I would spend the money on the right cam and matching components, and cheap headers for that 318. Even by not having to bvuy head gaskets and the associated gaskets needed, you can buy cheap headers that will make a feelable difference with any cam or intake. I'm also thinking you already have a dual exhaust. If you dont, that is job 1.
 
DdgeDartboi said:
thats a good looking teen..... im guessing that is ram air tubes... where do you have the inlets at... in the grille? or where
Click to expand...


yea its ram-air.

one is behind the grille, to the right.

100_1018.jpg


other picks up from a scoop under the valance.
doneram1.jpg
 
Mopers right. The draw back to a 360 head on a teen is not only the larger chamber decreaseing the comp. ratio even further but also ports to large to make effective useable power in most applications on the street. Even more so if the pistons are stock in the teen.

For a cheap and easy way to increase power, yea, fine. The better way is more expensive. Porting the 318 head. It is also combo dependent.
Whats yours?

I would do what Goody did and increase the tire height and T-bar height and use headers into a "X" pipe. 2-1/4 pipe to about 280 -290 HP, 2-1/2 for any HP level above that.

If your going to use the 360 heads, have them mill the deck approx. .060 for a bump in the comp. ratio. You'll also have to mill the intake surface a bit to fit the manifold. A possible elongation of the intake bolt holes may result, but thats easy to do.
 
rumblefish360 said:
Mopers right. The draw back to a 360 head on a teen is not only the larger chamber decreaseing the comp. ratio even further but also ports to large to make effective useable power in most applications on the street. Even more so if the pistons are stock in the teen.
Click to expand...

Just as far as that goes, in my application. I have milled J's. 56cc chambers, block was not decked, just plain replacement cast flat-tops and i'm turning 9.7:1 compression. Heads/intake the previous owner had the intake milled to the heads and not vise-versa. (if you mill the heads, mill the intake face, not the intake)
 
Goody, I think you may have mentioned in another post but how much was milled off the head and how much needs to be milled on the intake side to compensate?

Also, what size front tires are you using?
 
Actually the previous owner had the heads and intake milled already when i got the two. So, sorry, i cant say how much has been milled off of them.

And my fronts are just 235/60/15s
 
WOW! Big mil there Goody.
Ummmm, the 235/60/15's are stock size right?
 
Another interesting option would be a set of stock JY Magnum heads. Replace the springs with ones for your cam, buy the AMC lifters and pushrods, and bolt them on. Smaller chambers, good flowing ports, and basic bolt on, plus adds a little cam lift and duration because of the 1.6 rockers. You would need to have your heads drilled for the LA intake pattern, but that's no big deal really. Headers lose ground clearance, but not more than 1-1.5" or so. And the power benefits can be pretty good. Another thought is you may want to upgrade the exh manifolds to Magnums too. They flow similar to the expensive 340HP manifolds, and will be much cheaper. You will need to have your exhaust system hooked up to it tho.
 
rumblefish360 said:
Ummmm, the 235/60/15's are stock size right?
Click to expand...


Beats me, my car came with 14" with little short tires and i had bump issues. I cant remember the last time i smacked my headers and i daily drove it, i'd have to say atleast a year ago. :salute:
 
yeah i have small tires on the front of mine right now and im in the process of upgrading my torsion bars to the V8 cause i have the original bars on it and it was originally a /6 car..... if anyone could give me some websites or something that will help me find some of these heads it would be appreciated.... im really not looking foward to having machine work done around here for the simple fact that people are really liking there work around here and charging an arm and a leg for a 3 way valve job alone so there is no telling what they would charge for other things.... keep the ideas coming by the way im looking for all the help i can get right now... if you have any specific questions about my build as of now that would help you in helping me please ask and i will tell
 
I would suggest you pay what good labor is worth. Trust me, you'll pay once to do it right, or pay once to do it, then again to do it right, and fix whatever else got broke in the process. BTW, why cahnge to V8 torsion bars? That's an expense you dont need. /6s are very close in weight to a small block. If your nose drops at all, crank the adjuster screw up a turn or 2. If you go to an iron big block, I would reccomend replacement. But not for a small block. Right there you can save $150 on the bars and $50-100 for the alignment.
 
well i am in the process of doing my entire front suspension anyways so i figured i would go ahead and do the torsion bars as well..... i don't have to pay anything for the alignment cause i have a 3 year warranty free alignments on my car.... so thats no big deal thats nothing else outta my pocket.... im thinking that i might do the machine shop thing but like i said its just a little out of my budget right now..... they seriously wanted like $400 per head for a 3 angle valve job..... does that sound about right to you guys.. seriously
 
With parts, it sounds right. Labor is $250 where I go (East coast) for 2 V-8 heads. But the parts..Valves*, guides*,seals, seats*,springs, retainers, and locks add up fast.
*-means if needed...
But if you read, I said "JY". Meaning go to a recycler, buy 2 heads and rockers with a gauranty of being not cracked. Then have the shop clean and pressure test them. It is fairly common for Magnum heads to have cracks that do not effect the cooling system or performance. So magnafluxing may show cracks. Pressure testing will tell you if they are good or not. If they pass, replace the springs with a set of performance ones that have the tension your cam needs, and you're good to go. Between the pressure test, the labor to swap springs, and drilling the intake holes in the heads for the LA intake shouldnt cost more than $200 depending on the spring costs. And those can be Chevy LS1 parts so they will be cheaper anyway. Then bolt them on using AMC lifters and the Magnum pushrods.
 
There is an excellent article on building a teen with 416 hp in the Engine Masters magazine, winter edition 2006 using 360 heads. I'm with Moper though. Flat top pistons with a quench style head is the key to torque production and detonation resistance.
 
Nothing wrong with building a 318...I had a 318 Dakota that ran 12.30's all day long on nitrous. Stock bottom end, stock heads. Cam, intake, TB and headers were the only bolt ons. It commanded alot of respect from the local R/T crowd...
 
You must log in or register to reply here.
-

Back
Top