The mighty 318! Help with compression, and head/piston combos…or even a stroker!

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I think some of you are missing the fact this post is just a troll post. I think it's the same guy who was gonna bore his block with a mag drill and cut his piston tops with a band saw.
RRR treed Me, that's ban saw,........& You know, 'cause machine shops are such F'n rip-offs. It's all good, He can enjoy His cylinders that look like drunken snakes dancin' the Macarena......
 
RRR treed Me, that's ban saw,........& You know, 'cause machine shops are such F'n rip-offs. It's all good, He can enjoy His cylinders that look like drunken snakes dancin' the Macarena......
There used to be a machine shop that was in Macon for YEARS. The daddy started it back in the fifties when he got out of the Navy. He was a true machinist. The son took over as the daddy aged and then passed on. The daddy did it all. Stock, street, race and anywhere in between. Chevy, Ford, Mopar all other GM, whatever. He took it in and did a good job on everything. They had a good reputation for a long time. After the daddy's death, the son stopped giving a crap about anything but all his Chevy buddies stuff. They ended up finally having to close that shop down and moving to a county further south......where they actually lived on their own property, because they were doing so poorly they couldn't afford to stay where they were. They're further away from me now than they were, but I wouldn't take him a Briggs and Stratton.

I got sidtracked, but where I was goin with all this was, the son used to really use a belt sander to surface heads and blocks and he bragged about it. We always just laughed.
 
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heads what makes the power, c.i. and stroke and cam dictate at what rpm it dose it, gonna need more head than 302s to get where you wanna go, ant enuff meat in them to port them enuff 375 to 400 bout best theyll do and be lucky to do that and not leak water!! ask steve duluchie...lol ...more stroke gonna need even more head to feed it too... speed cost, how fast can ya afford to go???
Yup some folks don't get that no matter what you tell them them 273 318 heads are their own casting and its smaller overall.
I've given up arguing with 318 folks but one of the last things I said to one of them was"disassemble a 318 and a 340 and have the parts on a bench side by side you'll see the overall difference..." one of the misconceptions is a 340 was derived from a 318. a 340 is actually an overall redesign of the LA engine to make it a performer
 
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Yup some folks don't get that no matter what you tell them them 273 318 heads are their own casting and its smaller overall.
I've given up arguing with 318 folks but one of the last things I said to one of them was"disassemble a 318 and a 340 and have the parts on a bench side by side you'll see the overall difference..." one of the misconceptions is a 340 was derived from a 318. a 340 is actually an overall redesign of the LA engine to make it a performer
i got a set of them 302s and thought i had something really good! not saying there bad cause thay ant, there a fine head for a streetabile 318 up to 350ish hp but a high performance head thay are not!! hate to give up my shaft mount rockers but on my budget stock magnums best bang going for me, most yall got more money in ya motors than im trying to build the hole car for....
 
i got a set of them 302s and thought i had something really good! not saying there bad cause thay ant, there a fine head for a streetabile 318 up to 350ish hp but a high performance head thay are not!! hate to give up my shaft mount rockers but on my budget stock magnums best bang going for me, most yall got more money in ya motors than im trying to build the hole car for....

Throw them on the marketplace.. i just got $175 for a pair.. which made me even think WTF? i over priced em and guy didn't even try to talk me down..
 

Throw them on the marketplace.. i just got $175 for a pair.. which made me even think WTF? i over priced em and guy didn't even try to talk me down..
saving them incase i ever wanta build a 318 to replace the /6 in my d100.... thay good for that type build!
 
saving them incase i ever wanta build a 318 to replace the /6 in my d100.... thay good for that type build!
i've built about two handfuls of 318's with 302 heads. if you don't go absurd with the cam and keep your expectations realistic they can make excellent little truck motors.

the P4452761 & P4452759 are both excellent choices as is the even mellower P4452755 (i've even run this one with a 2bbl)
 
How much of a CR bump were talking here ? 1/2 a point ? To swap just for that don't seem worth it, but if you building an engine around them I can see them be a decent performer.
 
How much of a CR bump were talking here ? 1/2 a point ? To swap just for that don't seem worth it, but if you building an engine around them I can see them be a decent performer.
they come in around 56~65cc and have a "fast burn" or "swirl" port. they're also closed chamber, so you can get some quench benefits.

for a small motor, they're decent.
 
they come in around 56~65cc and have a "fast burn" or "swirl" port. they're also closed chamber, so you can get some quench benefits.

for a small motor, they're decent.
I get that but a lot of the times when there suggested, it's someone hopping up a stock running 318 with cam 4bbl and exhaust and a few push them as a must do swap to make it work, not saying they wouldn't help but in that circumstance unless there basically free and running shape and even then for the effort to swap is probably not overly worth it but if you got to dig up some and especially machine them it really not worth it.
 
Hello! Im one of those guys who really likes the 318, 400 crank with only a cam, intake, carb and flat tops that actually reach within 20 thou of the quench pad in 302 heads is the street build I had a while back in my 61 lancer. I want to go farther though and want some tips as I have a better skill set now, and a better understanding of how these engines make power but I’m no genius.

Now I’m not some top of the line engine builder, I’ve rebuild engines back to stock but customizing them? Never anything internal.


i have two plans (and don’t tell me to get another motor, I want to use the 318). Both use the 318, I’m capable of building these engines, I want static compression to be no less than 10.5 to 1 and no higher than 11.5-12 to 1.

If you know exactly what parts will give me that compression ratio please tell me, or what parts may put me in the ball park!

Plan 1: stroker kit to a 390 (4.0” stroke) and some 302 close chamber heads or depending on compression numbers maybe X or J heads with the bigger valves for the longer stroke. My questions here are, what would street drivability be like here? What compression ratios can I expect between the 302’s and the open chamber larger valve heads? The 302 valves definitely aren’t a bottle neck of any sort.

Plan 2: Kb pistons makes the 167 flat top which seems to be the closest to 0 deck I can find in my experience having rebuilt a few before with mold upgrades, these with the 302’s seem like they’d hopefully produce the numbers I’m looking for (450 crank because I had that number from a customers engine who supplied all the parts, I believ the aluminum heads they had made the biggest diff)

Plan 2B: kb399 domed pistons but I have a problem with these. If they don’t fit the closed chamber heads I’d rather switch to flat tops than switch to a more open head. The 399 if I ground down the spark plug area like some 340 and 360 aftermarket domed pieces I bet it will fit. That’s if they hit at all and I understand this combo will not be okay with pump gas (most likely, if the 302’s fit I can use the quench pad to help detonation but still)

I want to know if anyone’s ever ran 399’s on the heads I mentioned or ran 399’s at all. What did you think? How was clearance?

And do you think I’ll get higher compression using open heads and domed pistons or 0 deck flat tops with closed chamber 302s?

As I said before, the 318 is a must. I’m open to open chamber heads if someone explains why it’d make good power.

The few things I do know:
At work the guy who does the headwork and has build many a small block mopar says the stock valves are fine to 5500rpm but the ports are restrictive, now I know how to port so I’ll be doing that.
I don’t want to notch the bores in the block. Also what’re your 318 power build numbers? At the shop our most powerful was 590 crank NA with a 318, cam pistons heads sprints intake carb headers yada yada. My goal is 475 crank, hopefully a little under 400 at the wheels if not 400 mentioned in the beginning I have pieves together multiple 318’s with those numbers but I didn’t pick the parts I just assembled them. Anything ultra high performance I still need more certs and experience first.

TLDR: what combo workk get me minimum 450 crank on a 318, stroker? Flat tops and closed chamber or domes and open chamber?

!!!!This is for a dodge aspen R/T with original stripes and blacked out chrome, factory lip spoiler and all the louvres!!!
Found a burgundy interior for it as well out of a junk 2 door because the rt has nothing good inside besides the dasg
ALWAYS BUILD THE BIGGEST CUBE ENGINE YOU CAN IF YOU ARE GOING ALL THE WAY THRU IT... SELL THE 318 , USE A 360 BLOCK AND STROKE IT... ALUM HEADS AND YOU HAVE 600 HP EASY... 318 STROKED[ UNLESS BOOSTED] MIGHT GET 450 ISH AS EASILY .. GLTU
 
If your just slapping on heads with a lap job, Dig up some cheap magnums and a china air gap would be the swap I'd suggest cracked or not at least there's a flow gain as well. Too bad mopar screwed up by making magnum heads so cracked prone would be the perfect head for all 300-400hp builds, 450 hp with some work.
 
ALWAYS BUILD THE BIGGEST CUBE ENGINE YOU CAN IF YOU ARE GOING ALL THE WAY THRU IT... SELL THE 318 , USE A 360 BLOCK AND STROKE IT... ALUM HEADS AND YOU HAVE 600 HP EASY... 318 STROKED[ UNLESS BOOSTED] MIGHT GET 450 ISH AS EASILY .. GLTU
or.. 535 out of a 318 without a radical cam...

it's 18 cubes under a 408.. if 18 cubes made all the difference in the world guys wouldn't pray to the alter of the 340 when 360s are easy to find :)

 
ALWAYS BUILD THE BIGGEST CUBE ENGINE YOU CAN IF YOU ARE GOING ALL THE WAY THRU IT... SELL THE 318 , USE A 360 BLOCK AND STROKE IT... ALUM HEADS AND YOU HAVE 600 HP EASY... 318 STROKED[ UNLESS BOOSTED] MIGHT GET 450 ISH AS EASILY .. GLTU
Wouldn't 440 be the biggest stock displacement readily available ? why waste your time with 80 cid less ? Basically twice the size difference between 318 vs 360.
 
Wouldn't 440 be the biggest stock displacement readily available ? why waste your time with 80 cid less ? Basically twice the size difference between 318 vs 360.
soo many times i have been like... man i coulda just stroked a 400 :)
 
soo many times i have been like... man i coulda just stroked a 400 :)
361/383/400 413/426/440 all are capable of eclipsing most probably all stroker small blocks. Why I find the 360/408 police funny, no replacement displacement as long it's a 360 or 408 :)
 
361/383/400 413/426/440 all are capable of eclipsing most probably all stroker small blocks. Why I find the 360/408 police funny, no replacement displacement as long it's a 360 or 408 :)
well 18 cubes is the difference between junk and glory :)
 
The beauty of a 318 is they were once cheap or free if you have to lay out cash go with something else. They were never meant to dump boatloads of cash into
 
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