Another cheap *** budget 318 build

[Slantsix64]

Hey guys, I got this 1972 318 low compression 8:1 motor.
Trying to keep this as cheap using parts on the car already!

What I’m running a offenhauser four barrel intake
600 CFM edelbrock
Hei ignition set up
Stock early abody manifolds for now. Might swap to magnum passenger manifold and early 340 manifold driver.

Sending the camshaft to Oregon Cams 218/224 @50 .462/470 with 1.5 rockers
Going to port the heads myself just going to swap valve springs to stock 340 replacements double roller timing chain.Camshaft will be installed 4 degrees advanced.

The Car is manual steering 66 Dodge Dart 4 speed (3.09) first with 3.55 in the rear.

I think I might be on the boarder line of over camming this thing, I really want to use the stock heads buttttttttttttttttt,

debating on running some straight out of the junkyard magnum heads would add some power but I know I would need valve springs plus the price of some used heads.

Hopefully I can just stick with the stocker 318 heads. What do you guys think?

 

[toolmanmike]

Run it as is. You can mess around, cost yourself time, money, and a lot of work and not gain much at all.

 

[318willrun]

Either way, be a fun toy

 

[PRH]

I don’t really like most offy intakes…….. let’s see a pic of yours.
For 8:1 and ex manifolds I’d step down one size on the cam.

 

[Slantsix64]

Here’s what’s on there.

 

[PRH]

Does it have a divider down the middle?

 

[Slantsix64]

Run it as is. You can mess around, cost yourself time, money, and a lot of work and not gain much at all.

Yep that’s what I’m thinking just run it with the stock heads, might be missing out on 20-35 HP versus the magnum heads

 

[Slantsix64]

Does it have a divider down the middle?

Not sure I’ll will have to check on that

 

[413]

Cam is too big for 8:1.

Offy intake isn't good.

 

[junkyardhero]

I agree. Magnum head's will lower the compression even more.

*buzzer sounds*

wrong again danimal.

Clean up the bowl area and the short turn radius, good valve on the stock heads. Edelbrock performer intake manifold and headers

stop regurgitating info that you've read or heard. come up with a thought of your own for once.

go back and READ his initial post. he wants to use what he has not spend 2K in parts off the jump.

 

[junkyardhero]

man... you just missed half off at the yard, you coulda scored on the heads!

i guess it depends on how bad the heads are when you pull it all down? if they're acceptable, i'd probably breath on them and run it, maybe roll 'em over to the machine shop and have 'em take a cut off to get a bump in comp.

i think the cam is a little big, but i skew toward smaller in the stuff i build out. if that's an offy 360 w/o the divider, you're not gonna have much bottom end or throttle response. so keep that in mind as a consideration on other aspects of the part selection.

 

[toolmanmike]

I agree. Magnum head's will lower the compression even more. Clean up the bowl area and the short turn radius, good valve on the stock heads. Edelbrock performer intake manifold and headers

Nope. Magnum heads have closed combustion chambers (like the 273 heads) 318 heads have open chamber heads.

 

[toolmanmike]

i think the cam is a little big, but i skew toward smaller in the stuff i build out. if that's an offy 360 w/o the divider, you're not gonna have much bottom end or throttle response. so keep that in mind as a consideration on other aspects of the part selection.

Cam's not bad. Probably ground on 112° possibly?

A LD4B or a Weiand Stealth may be a better intake choice but there again, another $400+ out of the budget. A cheap stock cast 4 barrel intake might be worth a try.

 

[junkyardhero]

Cam's not bad. Probably ground on 112° possibly?

A LD4B or a Weiand Stealth may be a better intake choice but there again, another $400+ out of the budget. A cheap stock cast 4 barrel intake might be worth a try.

it's not bad, and he's got a 4spd but i'm just a little more conservative on cam selection on smaller ci stuff. especially if you don't have the supporting cast (head flow, compression, carb).

with the 3.09/3.55 combo there's some saving grace, it'll hide a multitude of sins, but that intake/carb/cam it's gonna be dogwater downtown. 2nd/3rd will be nice on the street with a short tire.

 

[toolmanmike]

it's not bad, and he's got a 4spd but i'm just a little more conservative on cam selection on smaller ci stuff. especially if you don't have the supporting cast (head flow, compression, carb).

with the 3.09/3.55 combo there's some saving grace, it'll hide a multitude of sins, but that intake/carb/cam it's gonna be dogwater downtown. 2nd/3rd will be nice on the street with a short tire.

Mid rpm power can make up for lack of traction off the line. I remember that back in the bias ply tire days. The cam comes in and you blow buy the guy like he's going backwards.

 

[Dan the man]

Nope. Magnum heads have closed combustion chambers (like the 273 heads) 318 heads have open chamber heads.

My bad, I remember that now

 

[Slantsix64]

Hmm maybe I can sell those HIPO valve covers, sell off all that GT Trim, that offenhauser four barrel intake. That Holley carburetor. And buy a cheap *** RPM air ebay gap online and some used magnum heads at the junker......... going to need Hughes springs set and retainers as well.

 

[Slantsix64]

Low 13s here we come lol.............

 

[Slantsix64]

jk

 

[273]

Hey guys, I got this 1972 318 low compression 8:1 motor.
Trying to keep this as cheap using parts on the car already!

What I’m running a offenhauser four barrel intake
600 CFM edelbrock
Hei ignition set up
Stock early abody manifolds for now. Might swap to magnum passenger manifold and early 340 manifold driver.

Sending the camshaft to Oregon Cams 218/224 @50 .462/470 with 1.5 rockers
Going to port the heads myself just going to swap valve springs to stock 340 replacements double roller timing chain.Camshaft will be installed 4 degrees advanced.

The Car is manual steering 66 Dodge Dart 4 speed (3.09) first with 3.55 in the rear.

I think I might be on the boarder line of over camming this thing, I really want to use the stock heads buttttttttttttttttt,

debating on running some straight out of the junkyard magnum heads would add some power but I know I would need valve springs plus the price of some used heads.

Hopefully I can just stick with the stocker 318 heads. What do you guys think?

Here's a similar build, stock low cr 318 long block with a 218 cam making 282 hp.

3-8-Teen Dream

 

[HPP]

Got a similar '74 318 I'm preparing to throw into one of my cars and wanted to bump it up a bit in the "oomph" department, so I've been contemplating similar changes. Don't want to really get into a full rebuild with it, just a quick get it running better than it was when it came out.

After reading the porting article on here, I thought about doing that since it demonstrates some decant gains in flow, but losing the factory shim gasket for a .040 aftermarket gasket didn't excite me much. I question whether I could get a shim gasket to seal again, otherwise that would eliminate the loss of squeeze.

Thought about magnum heads as they flow well with more swirl and tumble than LA heads and have smaller chambers. They also don't have the cracking exhaust seat issue that the late LA 308 heads have. The small chambers will help the compression bump up some, which is always a good thing for power. The local pull-n-pay has heads for $65 each plus $10 core. I could always use my original 318 heads for the core. Haven't decided if I'll do this yet. The issue you will have if you use magnum heads is you will then need a magnum compatible intake. Magnum intakes bolt to the heads vertically, not at the intake face angle like an LA. There are some members here advertising the dual pattern intakes for around mid $200 new. Most Speed sites have them for upper $200s. I've seen them as low as $150 out on the interwebs but then you have shipping costs to add in.

Mine doesn't have a cam in it so I was planning on using a factory 340 grind. Not sure what Oregon Cams charges, but you can get a Summit branded 340 cam or a Rock Auto Melling 340 cam for about the same price - $280ish. The Summit cam is cheaper but doesn't come with lifters so once you add those in its comparable to Melling. The Melling is a complete kit with lifters and lube. Both places have them in stock for immediate shipment. The 340 cam is going to be similar to teh 318 build linked in the reply above.

Another option to look at if you have fabrication capability is to leave it as is, fab up the appropriate intake and discharge mounts and bolt on an M90 supercharger from a late 90s GM 3.8. Pull-n-pay gets $100 for these and you can find them any place on the web for around $250-300. Getting it to line up for the belt might take a bit of finagling.

You could also look at a turbo or two. Problem with these is a lot of custom exhaust work and the kids out there love scrounging these from yards so they aren't easy to find, and you will need a carb hat with a blow through capable carb, unless you are willing to compromise pressure with your non-modified 4bbl or upgrade it yourself.

Stepping up significantly in cost but giving you some future capability should you want to upgrade or change the block are new EQ heads. These are a magnum style replacement head that has slightly improved port flow over the magnums, the small chambers and come with dual bolt pattern intake faces. These are about $800 but are all brand new with new valves, seals, and springs. Certainly overkill for your current effort, but like I said, these present a lot of capability for future upgrade options on the short block.

 

[rumblefish360]

I agree. Magnum head's will lower the compression even more. Clean up the bowl area and the short turn radius, good valve on the stock heads. Edelbrock performer intake manifold and headers

Hold on Dan. How many cc’s is the current head and how many cc’s are the Magnum head?

Before you recommend a performance aspect and make a suggestion, please tell me and all of us here how many high performance MoPar engines you have built.

Nope. Magnum heads have closed combustion chambers (like the 273 heads) 318 heads have open chamber heads.

Depends on the 318 head.
Not all 318 heads are open chambered.

 

[rumblefish360]

Got a similar '74 318 I'm preparing to throw into one of my cars and wanted to bump it up a bit in the "oomph" department, so I've been contemplating similar changes. Don't want to really get into a full rebuild with it, just a quick get it running better than it was when it came out.

After reading the porting article on here, I thought about doing that since it demonstrates some decant gains in flow, but losing the factory shim gasket for a .040 aftermarket gasket didn't excite me much. I question whether I could get a shim gasket to seal again, otherwise that would eliminate the loss of squeeze.

Thought about magnum heads as they flow well with more swirl and tumble than LA heads and have smaller chambers. They also don't have the cracking exhaust seat issue that the late LA 308 heads have. The small chambers will help the compression bump up some, which is always a good thing for power. The local pull-n-pay has heads for $65 each plus $10 core. I could always use my original 318 heads for the core. Haven't decided if I'll do this yet. The issue you will have if you use magnum heads is you will then need a magnum compatible intake. Magnum intakes bolt to the heads vertically, not at the intake face angle like an LA. There are some members here advertising the dual pattern intakes for around mid $200 new. Most Speed sites have them for upper $200s. I've seen them as low as $150 out on the interwebs but then you have shipping costs to add in.

Mine doesn't have a cam in it so I was planning on using a factory 340 grind. Not sure what Oregon Cams charges, but you can get a Summit branded 340 cam or a Rock Auto Melling 340 cam for about the same price - $280ish. The Summit cam is cheaper but doesn't come with lifters so once you add those in its comparable to Melling. The Melling is a complete kit with lifters and lube. Both places have them in stock for immediate shipment. The 340 cam is going to be similar to teh 318 build linked in the reply above.

Another option to look at if you have fabrication capability is to leave it as is, fab up the appropriate intake and discharge mounts and bolt on an M90 supercharger from a late 90s GM 3.8. Pull-n-pay gets $100 for these and you can find them any place on the web for around $250-300. Getting it to line up for the belt might take a bit of finagling.

You could also look at a turbo or two. Problem with these is a lot of custom exhaust work and the kids out there love scrounging these from yards so they aren't easy to find, and you will need a carb hat with a blow through capable carb, unless you are willing to compromise pressure with your non-modified 4bbl or upgrade it yourself.

Stepping up significantly in cost but giving you some future capability should you want to upgrade or change the block are new EQ heads. These are a magnum style replacement head that has slightly improved port flow over the magnums, the small chambers and come with dual bolt pattern intake faces. These are about $800 but are all brand new with new valves, seals, and springs. Certainly overkill for your current effort, but like I said, these present a lot of capability for future upgrade options on the short block.

Flow over compression. Works every time. Don’t sweat a minor gain or loss in compression.

Magnum heads and 308 heads both have cracking issues but in non problematic areas. At least until the crack is grand crayon wide & deep. Once the valve can’t seal, that’s when there is a problem. But you’ll never know until you look for it.

 

[rumblefish360]

Hey guys, I got this 1972 318 low compression 8:1 motor.
Trying to keep this as cheap using parts on the car already!

My kind of build.

What I’m running a offenhauser four barrel intake
600 CFM edelbrock
Hei ignition set up
Stock early abody manifolds for now. Might swap to magnum passenger manifold and early 340 manifold driver.

Trade out the Offy if you can for a dual plane like a Performer or LD4B.

Sending the camshaft to Oregon Cams 218/224 @50 .462/470 with 1.5 rockers
Going to port the heads myself just going to swap valve springs to stock 340 replacements double roller timing chain.Camshaft will be installed 4 degrees advanced.

What porting are you doing?
Honestly anything more than bowl work and your wasting time since it’s the valve job and the bowl that really handle everything until around .500 lift where the short side is key.

The Car is manual steering 66 Dodge Dart 4 speed (3.09) first with 3.55 in the rear.

I think I might be on the boarder line of over camming this thing, I really want to use the stock heads buttttttttttttttttt,

Cam is small. 1400-5500 area. I used the old Crane 272/284 - 216/228 - 112 in a low compression ’79 - 318 @ a measure 7.9-1 ratio along with a 904, 3.21 suregrip equipped, stock tire on a ‘74 Duster with a LD4B, 600 carb, orange box and JY distribtor and header and Jegs 2-1-2 exhaust into the 14’s. Barley got out of second.

Heads where dead stock minus springs.
Cleaned them up with a worn out tooth brush and away I went.

debating on running some straight out of the junkyard magnum heads would add some power but I know I would need valve springs plus the price of some used heads.

Hopefully I can just stick with the stocker 318 heads. What do you guys think?

Any questions? Feel free to PM me while I’m still around.

 

[Dan the man]

Hold on Dan. How many cc’s is the current head and how many cc’s are the Magnum head?

Before you recommend a performance aspect and make a suggestion, please tell me and all of us here how many high performance MoPar engines you have built.

Depends on the 318 head.
Not all 318 heads are open chambered.

I made a mistake and I was given the correct information.