HELP! Need 318 Head Suggestion (info provided)

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YoungBlood

YoungBlood

Jolt the Squares
Joined
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Western WA
Since I’m still laid up at home, I have been doing a lot of reading and research, and only buying what parts will factually work. One little area that I’m getting some unclear info is Cylinder Heads.

I’m going to spare you guys that part of it, but basically my machine shop wants me to just buy Edelbrock Performer Aluminum heads and be better off that way.

My engine is a 72 318 2bbl Motor that appears to be like 180bhp and under 8.0:1 compression from the factory that I put a 4bbl and intake on and drove the piss out of for years.

I am rebuilding this engine (0.30“ overbore) and initially planned to freshen up these heads. I am going for reliability, and trying to keep everything around or under 275hp. I'm going to run the base Edelbrock Performer Intake and 600cfm carb. I want approx. 8.5 compresson.

All research leads me to believe that these 72 318 heads are 74cc chambered from the factory. Does this seem correct?

If so, theoretically, with these pistons…

http://www.hughesengines.com/Index/...Sk=&searchmode=partnumber&page=1&partid=10427

…they could instantly bump the motor up to 8.5:1 compression, without milling, correct?

Would installing 1.88/1.60 valves be a good, worthwhile idea?

I will be running a Comp HE260H Cam & Lifters.

http://www.compcams.com/Company/CC/cam-specs/Details.aspx?csid=618&sb=2

With that, I am going to run these pushrods…

http://www.compperformancegroupstor...tore_Code=CC&Screen=PROD&Product_Code=7958-16

…and these valve springs (recommended)

http://www.compperformancegroupstor...Store_Code=CC&Screen=PROD&Product_Code=901-16

Keeping my heads, getting a clean up, 3 angle valve job, and the 1.88/1.60 valves will run $640.

Buying the Edelbrock set up for that cam OOTB would be $1600+. That’s a lot of head for a very mild street 318, but I’m not opposed to it.

What would you* do?



*If you recommend Magnum heads, I appreciate that, but please don’t reply unless it‘s for recommending one of the two options mentioned. Thank you!
 
I really think that a 318 head with some minor porting (in the right spots) will get you to 275 HP. 1970 318's were rated at 230. (crankshaft hp). I measured a set of 1975 318 heads and they came out to 72 cc so the 74 reading could be considered "in the ball park". Another cheap option would be a set of 360 heads BUT, more compression would make them more usable in the lower rpms. I dont think you would need eddy heads unless you had more compression and a bigger cam. 360 heads would be good with a small cam. IMHO. (the smaller 318 port will keep the velocity up in the lower rpm range- they just dont breath as well at higher rpm) Open up the pushrod pinch a bit and blend the bowl area, smooth out the guide boss a little. Might get you to 5000 rpm with the right cam. JMHO. Enjoy!!
 
The edelbrock heads are great heads, but a little overkill for your application. The magnum heads will work great, but you will have a different head oiling system; pushrods oil the magnum rockers. Why only 8.5 compression? Personally, 9.5 would be the better street engine choice for compression.
 
74 is about right...........

Good cam choice.

Use the stock intake size valve, and put in a larger exhaust valve.

275HP is cake with stock heads.
 
Your set up seems pretty well thought out for what you want out of it. The chambers on your '72 318 heads probably aren't that big. They could be, but I would say that 74cc's is probably the absolute top end, its more likely that they're smaller than that. I'd have them cc'd to get their exact size to calculate your compression. Also, if you haven't torn the engine down yet, measure how deep the pistons are in the hole. The KB hyper's have a taller compression distance, you should be able to compare them to your stocker's to figure out how deep the pistons will be, which will also give you a better idea about the final compression ratio.

The stock heads will be absolutely fine for 275 hp. I would have them redone with 1.88/1.60 valves, but that's all you'll need to do. With those valves the stock heads should be fine for up to 300hp, maybe a little more. 275hp would be no problem.

I definitely wouldn't spend the money for the Eddy heads for the set up and results that you want. If you REALLY want to upgrade the heads, buy a stock set of Magnum heads and a new intake. You'll be money WAY ahead over the Edelbrocks, and with your performance goals you won't notice the difference. Keep in mind that with the Eddy's the price of the head isn't the only thing you need to look at, you'll also need to get their head bolts and a better head gasket since most recommend MLS with the Eddy's. And running an MLS head gasket means you should have your block surface refinished and...and...etc. I looked into getting Eddy's for my 340 build, which I set up for ~450hp. There's a lot of "extra's" that become necessary with the Eddy's, and the price adds up. Plus, I wouldn't run 8.5:1 with aluminum heads. Most folks usually spec an extra point of compression for aluminum heads, I'd want at least 10:1 with the Eddy's because they dissipate heat much faster than the stock cast iron heads.
 
dodgetkboy78 said:
74 is about right...........

Good cam choice.

Use the stock intake size valve, and put in a larger exhaust valve.

275HP is cake with stock heads.
Click to expand...

I agree with this. IMO, omahamoparguy has great advice that should be re-read. The stock head is just absoultely fine for what your doing.

I've run a dead stock '79 - 318 with just bolt on parts and a small cam Crane cam (216 - 228 - C-112 .454/.480 lift.) & 3.21 gears to 15.14 in the 1/4. (2.2 60ft.)
That would mean 7.8-1 comp. ratio and stock valved heads. More compresion and the 1.60 exhaust valve would have been a nice addition to that build.
 
All the non hp la motors were around 7.7 to 8.0

Take your head, clean up the bowls a little. mill it .040.
add the 2.02 and 1.60 valves
 
rumblefish360 said:
I agree with this. IMO, omahamoparguy has great advice that should be re-read. The stock head is just absoultely fine for what your doing.

I've run a dead stock '79 - 318 with just bolt on parts and a small cam Crane cam (216 - 228 - C-112 .454/.480 lift.) & 3.21 gears to 15.14 in the 1/4. (2.2 60ft.)
That would mean 7.8-1 comp. ratio and stock valved heads. More compresion and the 1.60 exhaust valve would have been a nice addition to that build.
Click to expand...

Of course you agree...... :scratch: :thumbup:

Omaha is on to it, however, the pinch in the small port heads isn't the bottleneck, the bottleneck is in the bowl. (mildly ported)... Yes, adding the bigger EX valve and a same/same cam..... (about that)

The higher exhaust flow at lower lift (starts faster) helps at higher RPM
The same/same cam, makes more low end than a cam with a longer EX duration.

So, with the change of the EX valve size (providing they are stock(ish) heads, you get a nice low end, (important to small motors) with a nice finish. (the point of the longer EX duration)

Any engine builder that wants you to just throw away your small port heads on a mild 318 is just trying to.....
(1) take the easy way out
(2) Doesn't know Mopar
(3) trying to make money off of you with minimal effort
(4) thinks your rich
(5) all of the above
 
What about some #302 heads? They are closed chamber and should bump your comp up. If you had 1.88-1.6 valves put in them that should help the "higher" rpm without loosing the lower end. and they use stock "shaft" rocker gear and oiling.
 
I have a set of ported 302 heads with 1.88/1.60's feeding my 390, they work great, feed it pretty well up to aout 4500, runs great past 5K though.

Here's the deal. The closed chamber 318 head won't give you higher compression, but, with a piston at the top, you will get all the benifits of a good quench....... and helps run **** fuel.
 
For your application the eddy heads would be the worst thing to do.For a motor that will not be turning big RPM,s,these heads would kill the power.Money spent on iron heads done really well with good ferrera valves and bowl work and multiy angle valve job,your on your way to great power.MMT
 
I like the 302 casting swirl port heads, i had a set done on my 318 in my 4x4 with 1.88/1.60 valves, and it worked real good... eddy carb/performer intake/and performer cam. real driveable good vacuum for brakes, even my chick could drive it.
 
I have read from many different sources that 318 heads on average are in the 62-64 cc range sometimes less, the 340/360 heads had the 74cc and up combustion chambers. I gotta get me a burette and cc my heads I have. They are pre-air port so they have to be older ones. From the casting number they were used 69-74.
 
Ditch the Performer intake. Get something a little taller like a performer RPM or LD4B, Weiand Stealth. I tried the Performer on a Dodge pickup and was worse than the stock 2bbl.
 
Then you did something wrong..................

The Action Minus Wieand has to be the worst small block manifold built as of yet......... Nothing like every spark plug a different color..........

But then again, some people don't catch that, but I do...........

Performer will do just fine, real close to a Stock piece.
 
rick360 said:
I have read from many different sources that 318 heads on average are in the 62-64 cc range sometimes less, the 340/360 heads had the 74cc and up combustion chambers. I gotta get me a burette and cc my heads I have. They are pre-air port so they have to be older ones. From the casting number they were used 69-74.
Click to expand...

my 302 heads were between 68 and 73...................

My 975 heads were 70 when I was done, 74 isn't a bad expaectation.
 
If you haven't already purchased your rebuild kit yet, suggest you specify a 1970 or earlier piston. This piston sits highest in the hole of any stock 318 piston.

FWIW: My Demon has a '68 318 with 302 heads, Performer, AFB, and mild Crane cam. Compression has been measured at 9.2:1. No milling. The 302 heads also provided me with good valve seats for unleaded gas. Throttle response is good. Haven't really hammered on it yet as I don't trust the 7¼ to put up with much abuse.
 
I think if it was me I'd do wht you say you're going to. Comp uses the AMC lifters for all Mopar cams now so there's nothing special there. You will more than liekly need special pushrods wonce you finish playing with milled decks and gasket choice so if it was me, I wouldnt order them until the longblock's together. Use a checking tool and look thru some catalogs and you can probably find some 5/16 drilled pushrods in the right length for cheap. You can get the "on par" EQ/Hughes heads for less than it will take to get the originals up to par or to better than par. For your level, stockish Magnums or a variant are fine.
 
Keep your heads. Saving the rest of the 1600 plus dollars on the edelbrocks can be spent on having 1.88 and 1.60 valves installed. That is all the valve your engine will ever need. You should also have enough to get some pocket porting work done. Also, I would do whatever I could to get compression up to 9.5. That is a safe compression ratio for pump gas and you will really see a difference in power. I mean a BLUEPRINTED 9.5, not throwin this part and that part to "get there", but an honest measured 9.5. with your cam choice and some good flowing headers with good induction, you should bump 400 HP.
 
[FONT=Arial,Helvetica,sans-serif]aeromax racing\part of indy

Best for the money for stock rebuild.
all new 1.88\1.60 s/s valves .509 lift springs
$399. a pair

Indy/rhs x head
I was told $950.for the rhs heads complete.
1.94\1.60 valves.



Chrysler Heads
These heads are reconditioned and come assembled with a "like new" apperance and quality, with all new Aeromaxx parts installed and a milled deck surface. These heads have outstanding features that include premium one-piece, stainless steel, high flow valves, heat treated and machined steel retainers and valve locks, seals, bronze wall valve guides, 3 angle valve job, and heavy duty valve springs. All heads listed accept their repscetive stock equipment (i.e. intake manifolds, exhaust headers and manifolds, valve train, valve covers, and accessory bolt holes) Must state cam lift when ordering head assembilies.
[/FONT]
[FONT=Arial,Helvetica,sans-serif]Small Block Heads (Assembled)
[/FONT]
.table_d2e26 { border: 1px solid rgb(0, 0, 0); width: 100%; background-color: rgb(255, 255, 255); }.table_d2e26 td { border: 1px solid rgb(0, 0, 0); } [FONT=Arial, Helvetica, sans-serif]Part
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Description​
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[FONT=Arial, Helvetica, sans-serif]Price
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[FONT=Arial, Helvetica, sans-serif][FONT=Arial,Helvetica,sans-serif]318[/FONT]
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[FONT=Arial, Helvetica, sans-serif][FONT=Verdana,Arial,Helvetica,sans-serif]1968-1987 318 A-Engine Heads, 1.88X1.60 Stainless Valves, 67-70cc Open Chamber Design, .509" Lift Springs[/FONT]
[/FONT]
[FONT=Arial, Helvetica, sans-serif][FONT=Verdana,Arial,Helvetica,sans-serif]$399.00[/FONT]
pair
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[FONT=Arial, Helvetica, sans-serif][FONT=Arial,Helvetica,sans-serif]340-360[/FONT]
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[FONT=Arial, Helvetica, sans-serif][FONT=Verdana,Arial,Helvetica,sans-serif]1968-1987 340-360 A-Engine Assem., 1.88 or 2.02X1.60 Stainless Valves, 67-70cc Open Chamber Design, .509" Lift Springs, 160cc Intake Port Volume[/FONT]
[/FONT]
[FONT=Arial, Helvetica, sans-serif][FONT=Verdana,Arial,Helvetica,sans-serif]$499.00[/FONT]
pair
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[FONT=Arial, Helvetica, sans-serif]915-587
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[FONT=Arial, Helvetica, sans-serif][FONT=Verdana,Arial,Helvetica,sans-serif]Same as 340-360 Utilizes Select #915 or #587 Casting with a Larger Intake Port Volume[/FONT]
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[FONT=Arial, Helvetica, sans-serif][FONT=Verdana,Arial,Helvetica,sans-serif]$599.00[/FONT]
pair
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[FONT=Arial, Helvetica, sans-serif][FONT=Verdana,Arial,Helvetica,sans-serif]Edelbrock 360 Performer[/FONT]
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[FONT=Arial, Helvetica, sans-serif][FONT=Verdana,Arial,Helvetica,sans-serif]Aluminum heads for the Chrysler 360 engine. Assembled with 2.02 x 1.60 stainless steel valves. [/FONT][FONT=Verdana,Arial,Helvetica,sans-serif]63 cc combution chambers, 171 cc intake runner, springs set up for .575 lift. [/FONT][FONT=Verdana,Arial,Helvetica,sans-serif]Ready too run. [/FONT]
[FONT=Verdana,Arial,Helvetica,sans-serif]ARP head bolt package recommended $75.00[/FONT]
[/FONT]
[FONT=Arial, Helvetica, sans-serif]
[FONT=verdana,geneva]$1335.00[/FONT]
pair​
[/FONT]
[FONT=Arial, Helvetica, sans-serif] IE-1AS

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[FONT=Arial, Helvetica, sans-serif]Indy IE-1 assembled heads complete with up to .650" roller springs, port match, roller rockers, shafts spacers, clamps, shaft stud kit, 2.05 & 1.60 stainless stell valves, 63cc chamber volume, 175cc int port volume
includes ARP head bolt kit and cut to length pushrod kits
[/FONT]
[FONT=Arial, Helvetica, sans-serif]click here to view spec. sheet[/FONT]
[FONT=Arial, Helvetica, sans-serif][FONT=Verdana,Arial,Helvetica,sans-serif]$2480.00[/FONT]
pair

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[FONT=Arial, Helvetica, sans-serif]Opt.
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[FONT=Arial, Helvetica, sans-serif][FONT=Verdana,Arial,Helvetica,sans-serif]2.02X1.60 11/32 Valve Stem Upgrade on 340-360 and 915-587 Assemblies Above, Lightens Valve Train Weight[/FONT]
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