Moparts
450 horsepower 318??
Posted By: 70Dart499
450 horsepower 318?? - 03/13/13 10:47 PM
Thinking about swapping my bigblock for a SB in my Dart, and I was wondering, how hard would it be to make between 450 and 500 horsepower with a stock stroke 318? What heads, intake and cam would be best..
Posted By: moparpollack
Re: 450 horsepower 318?? - 03/13/13 10:49 PM
Is boost an option?
Posted By: dogdays
Re: 450 horsepower 318?? - 03/13/13 11:00 PM
It'd be hard without a power adder, and the engine would be a bear to drive on the street. Look at Steve Dulcich's two different 400hp 318 articles, one with max ported 302 heads, the other with 360 heads, to see that to get to that level he used a camshaft quite big for a 318 on the street. Adding another 50hp to that would take some doing, IMHO. It'd be like falling out of bed with a 4" crank, the right heads and pistons, though.
R.
Posted By: 70Dart499
Re: 450 horsepower 318?? - 03/13/13 11:30 PM
Not interested in a power adder since I bracket race, but It's not a street car. I don't think I was clear, I was thinking of something with aftermarket heads, intake &pistons
Posted By: Skeptic
Re: 450 horsepower 318?? - 03/13/13 11:31 PM
Nitrous and/or a 4" crank.
Posted By: Triple Threat
Re: 450 horsepower 318?? - 03/13/13 11:47 PM
First question would be why?
Secondly yes it can be done. My stroked 318 made 525+ There are more economical ways to make the power.
Posted By: 70Dart499
Re: 450 horsepower 318?? - 03/14/13 12:02 AM
Quote:
First question would be why?
Secondly yes it can be done. My stroked 318 made 525+ There are more economical ways to make the power.
Why, i bought my car with the BB in it and I'm not much of a big block guy, and my car is a original smallblock car so I would like to put one back in it. Not dead set on a 318, though just exploring options.
Posted By: 1Fast340
Re: 450 horsepower 318?? - 03/14/13 12:04 AM
a good set of ported W2 heads and dont be afraid to turn the rpm it takes. M1 W2 single plane intake and enough compression to suport a 250-255 somethingdegree at .050 lift cam
might even make more than 450hp
Posted By: Duner
Re: 450 horsepower 318?? - 03/14/13 12:11 AM
I wouldn't limit myself to just a 318 if the only requirement is a smallblock..... but at least you didn't say you wanted to do it with a 273!
Posted By: 70Dart499
Re: 450 horsepower 318?? - 03/14/13 12:22 AM
Quote:
I wouldn't limit myself to just a 318 if the only requirement is a smallblock..... but at least you didn't say you wanted to do it with a 273!
I honestly think a 340 would be cool since that's what's the car came with, but I don't think I'll be able to find a 340 block that's not really expensive
Posted By: Streetwize
Re: 450 horsepower 318?? - 03/14/13 12:35 AM
you can get 450 out of a a 318 but it takes a lot of RPM to get there, ..so the peaky "327 chevy" style powerband won't 'feel' much like 450 unless you're beating the snot out of it.
I built a 341" 3.55" crank 318 a few years back and it was a screamer with actually pretty decent torque, pretty easy to do a low buck 360 crank and with a 6" rod a 9:1 flat top 318" KB piston will wind up right at (or just slightly over) zero deck.
Posted By: Twostick
Re: 450 horsepower 318?? - 03/14/13 12:38 AM
I would become more of a "big block guy"
Kevin
Posted By: PurpleBeeper
Re: 450 horsepower 318?? - 03/14/13 01:45 AM
Maybe think a heavily stroked 360 with the best heads you can afford, the biggest cam you can tolerate and light weight internal parts? You start out 100hp in the hole switching from big block to small block. Sounds expensive... but definiteiy can be done.
Posted By: Belvedere2
Re: 450 horsepower 318?? - 03/14/13 01:48 AM
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I wouldn't limit myself to just a 318 if the only requirement is a smallblock..... but at least you didn't say you wanted to do it with a 273!
I honestly think a 340 would be cool since that's what's the car came with, but I don't think I'll be able to find a 340 block that's not really expensive
Depends on your budget. And if you live anywhere near me. I'll be selling my 340 soon. 406hp dynoed, 9.8comp runs on pump with a small cam, with W2 heads. Bump the comp bigger cam it'll easily run those numbers. Putting in my 380 this spring so it'll go or just end up sitting. PM if interested. 
Posted By: Quicktree
Re: 450 horsepower 318?? - 03/14/13 01:59 AM
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I wouldn't limit myself to just a 318 if the only requirement is a smallblock..... but at least you didn't say you wanted to do it with a 273!
I honestly think a 340 would be cool since that's what's the car came with, but I don't think I'll be able to find a 340 block that's not really expensive
where do you live? i know where you can find one 
Posted By: LaRoy Engines
Re: 450 horsepower 318?? - 03/14/13 02:00 AM
Quote:
Thinking about swapping my bigblock for a SB in my Dart, and I was wondering, how hard would it be to make between 450 and 500 horsepower with a stock stroke 318? What heads, intake and cam would be best..
292ci/273, Indy 360X heads ported by LaRoy, Edelbrock Super Victor 2815, big solid roller, 93 octane, 462 HP
Posted By: rickstershemi
Re: 450 horsepower 318?? - 03/14/13 02:08 AM
Quote:
Not interested in a power adder since I bracket race, but It's not a street car. I don't think I was clear, I was thinking of something with aftermarket heads, intake &pistons
Just my 
but if your planning a serious bracket racing effort.....a big block, glide and as much tire as you can get under the car would be the best approach and way easier to maintain....just my opinion 
Rickster
Posted By: quickd100
Re: 450 horsepower 318?? - 03/14/13 11:23 AM
My
, there's no replacement for displacement, I'd stay with the BB. It's alot cheaper and easier on parts to run a big mild motor than a hyper rpm small block.Dave
Posted By: MPerry
Re: 450 horsepower 318?? - 03/14/13 11:40 AM
My car was originally a 318. I was going to try that 400 hp buildup that was in the magazine. The machine shops around here didn't feel comfortable in putting the big valves in 302 heads. I got frustrated and swapped a 413 big block in after a crappy day of bracket racing. It knocked 3 seconds off my et.
Posted By: Pale_Roader
Re: 450 horsepower 318?? - 03/14/13 12:18 PM
Quote:
Quote:
Thinking about swapping my bigblock for a SB in my Dart, and I was wondering, how hard would it be to make between 450 and 500 horsepower with a stock stroke 318? What heads, intake and cam would be best..
292ci/273, Indy 360X heads ported by LaRoy, Edelbrock Super Victor 2815, big solid roller, 93 octane, 462 HP
Hah! Why...???
I mean, thats damn cool, i love screamers, but with all the stroker hype out there, why would someone build a 462HP 273...???
Personally, i'd love to see this thread grow into some good examples. I'm also thinking about a stock stroke 318 for my next engine, and it'd need over 400HP too. I was fantasizing about Magnums though...
That 360 Magnum magazine build-up linked in my 360/383 thread made 455HP with Edelbrock Magnum heads and the usual stuff. That'd be about 400HP with a 318 Magnum... and there was nothing tricky about that engine and no porting in the heads yet. I think 450HP would be pretty easy with the same combo plus bigger (but not stupid) cam, and some simple head porting? Hmmm...
Posted By: Pale_Roader
Re: 450 horsepower 318?? - 03/14/13 12:19 PM
Quote:
I built a 341" 3.55" crank 318 a few years back and it was a screamer with actually pretty decent torque, pretty easy to do a low buck 360 crank and with a 6" rod a 9:1 flat top 318" KB piston will wind up right at (or just slightly over) zero deck.
Offset ground 360 crank...???
Ok I can see wanting to go with a small block but why go about it the hard way. Go to your local junk yard or Craigslist and get yourself and older 360 engine and here's a very simple low rpm combo.
.030 over app 11.0- 11.4 comp flat-tops.
nice set of H-beem rods (I used K1's)
polish or cut stock 360 crank
Balance the assembly.
Edelbrock heads. mildly ported
victor 340 intake, gasket matched
750 holly carb ( I used a 1" open spacer )
520 lift Racer Brown cam
1 7/8 Headmen headers
I used a 7 Qt. Milidon oil pan
This combo ran 10.20's in my 2550 pound Duster using 93 octain pumpgas and shifting at 6400 rpm. These heads like I said were ported but VERY mildly. I would guess its in the 450 hp range. Do yourself a favor and scrap the 318.
Posted By: Mr.Yuck
Re: 450 horsepower 318?? - 03/14/13 01:38 PM
Wow that's asking a lot. You can do it but it will cost you 2-3x as much to do as the BB.
Posted By: Streetwize
Re: 450 horsepower 318?? - 03/14/13 02:19 PM
The 3.55 stroke was an MP 8 bolt crank and the rods were 6" aluminum MP parts as well. Rev'ed REALLY nice but to a lot of bore notching to clear those 318 bores for the fat aluminum rods. It was a 30k mile standard bore hydraulic roller block, with a solid that thing would have loved to rev to 8K with the right heads.
The point is you make you a 10:1 340-350 ish 318 motor without a lot of creativity, there's still a lot of those MP 3.51 or 3.55 cranks out there with 340 mains. Speed o motive sells a 360 crank based 350 kit. But then it's about as cheap to do a 4" 390
Posted By: LaRoy Engines
Re: 450 horsepower 318?? - 03/14/13 03:10 PM
Quote:
Quote:
Quote:
Thinking about swapping my bigblock for a SB in my Dart, and I was wondering, how hard would it be to make between 450 and 500 horsepower with a stock stroke 318? What heads, intake and cam would be best..
292ci/273, Indy 360X heads ported by LaRoy, Edelbrock Super Victor 2815, big solid roller, 93 octane, 462 HP
Hah! Why...???
I mean, thats damn cool, i love screamers, but with all the stroker hype out there, why would someone build a 462HP 273...???
Personally, i'd love to see this thread grow into some good examples. I'm also thinking about a stock stroke 318 for my next engine, and it'd need over 400HP too. I was fantasizing about Magnums though...
That 360 Magnum magazine build-up linked in my 360/383 thread made 455HP with Edelbrock Magnum heads and the usual stuff. That'd be about 400HP with a 318 Magnum... and there was nothing tricky about that engine and no porting in the heads yet. I think 450HP would be pretty easy with the same combo plus bigger (but not stupid) cam, and some simple head porting? Hmmm...
Why? Yeah, good question. It was what was made available for the cylinder heads. Would have loved to put them on something bigger but the people building the short block chose the 273. The heads still sit on the shelf now two years later with the Chevy rockers, stud girdle, valve covers, and intake manifold, waiting for another short block. I'll switch the valves to someting bigger than the 1.94" intakes that are in there now. That was the biggest valve we felt would work with the big bore 273.
Posted By: JBurch
Re: 450 horsepower 318?? - 03/14/13 03:29 PM
FWIW, several years ago, in Engine Masters, a Adney Brown of Precision Crankshaft built an iron headed 318 that made 477hp at 6500rpm; that was the top of the pull, I suspect it would have kept going a little more. I have the copy of "Popular Hot Rodding" that featured the build; I'll look for it.
It's written up in the January 2009 issue of "Popular Hot Rodding", the high lights: .030 over, Diamond pistons, Comp solid flat tappet,
247@.050 I & E, 1.7 Harlen Sharp intake rockers, Crane 1.6 exhaust, ported Magnum R/T heads(used super stock cast off's), Chinese air gap, 950HP Holley, 10.44 compression.
Posted By: 74yellowduster
Re: 450 horsepower 318?? - 03/14/13 03:46 PM
Quote:
Thinking about swapping my bigblock for a SB in my Dart, and I was wondering, how hard would it be to make between 450 and 500 horsepower with a stock stroke 318? What heads, intake and cam would be best..
a BB makes that without even breaking a sweat. (less $$$ too)
really.
a SB you have to build the hell out of it for the same HP. sure you can do it, but it takes a lot more work. not to mention BB heads flow way more than the smaller heads.
here... take a look at this guy's 383 lol... we are not even talking a 440 or a stroked 400 451-500 or a even a stroked 440. this is what a lil 383 can do. http://www.youtube.com/watch?v=9K6ard18yo8
a guy on here named Hutch posted that over in another thread:
https://board.moparts.org/ubbthreads/show...part=2&vc=1
is there something wrong with your current BB?
Posted By: mopar65
Re: 450 horsepower 318?? - 03/14/13 11:46 PM
its your car and you can do with it what you want to, but how come you cant just tune the engine you have? what kind of compression are you running? do you have aluminum heads on the 499? i am racing my car on 93 pump gas and my times are in my sig. so if my little 0.030 440 can do it your 499 should have no problems running what my car does or even go faster. i have right at 11.1 compression.also if you do go small block you are going to have to start over with everything.but if you do decide to go small block i would by pass the 318 build and build a 408 out of a 360 block. but what ever you decide to build best of luck to you. Mopar65
Posted By: RUNCHARGER
Re: 450 horsepower 318?? - 03/14/13 11:54 PM
Start with small bore valve shrouding and take it from there. There is just no good reason to do a 318.
Sheldon
Posted By: Brian Hafliger
Re: 450 horsepower 318?? - 03/15/13 03:53 AM
Quote:
Not interested in a power adder since I bracket race, but It's not a street car. I don't think I was clear, I was thinking of something with aftermarket heads, intake &pistons
4" crank, RHS heads, soild FT cam, 10.2:1, rpm intake or victor, 750-950 carb will get you 500HP no problem.
Brian
Posted By: patrick
Re: 450 horsepower 318?? - 03/15/13 01:45 PM
figure to make 450HP out of a stock stroke 318, it's going to have to spin...
for a good, solid HP build, expect peak torque to be ~1.2x displacement....so for a 323" motor (.030 over 318) you're looking at maxing out at about 390 lb-ft of torque....
to get 450 HP, you'd need the torque peak to occur at 6100 RPM....or if your peak torque is lower RPM wise, you'll have to make sigificant torque higher in the rev range....say, you're making 90% peak torque at the HP peak, so ~350bt-lb...you'd have to spin the motor to 6750RPM to make 450HP...80% peak torque at the HP peak....so ~310 lb-ft...you'd have to wind the motor to 7600 RPM to make 450HP.....
gonna be a peaky, high stressed motor...I'd rather go more displacement and lower the peak RPM for longevity....a 408CID small block can make 450HP at 5000-5500 RPM, and 100 more ft-lbs of torque than a 318....
Posted By: Pale_Roader
Re: 450 horsepower 318?? - 03/16/13 01:59 AM
Quote:
figure to make 450HP out of a stock stroke 318, it's going to have to spin...
for a good, solid HP build, expect peak torque to be ~1.2x displacement....so for a 323" motor (.030 over 318) you're looking at maxing out at about 390 lb-ft of torque....
to get 450 HP, you'd need the torque peak to occur at 6100 RPM....or if your peak torque is lower RPM wise, you'll have to make sigificant torque higher in the rev range....say, you're making 90% peak torque at the HP peak, so ~350bt-lb...you'd have to spin the motor to 6750RPM to make 450HP...80% peak torque at the HP peak....so ~310 lb-ft...you'd have to wind the motor to 7600 RPM to make 450HP.....
gonna be a peaky, high stressed motor...I'd rather go more displacement and lower the peak RPM for longevity....a 408CID small block can make 450HP at 5000-5500 RPM, and 100 more ft-lbs of torque than a 318....
Hah!!! Now i REALLY wanna hear that Indy-X headed 273 at WOT...
It really does sound like a lot, and i'm not disagreeing with you (i think the OP should just skip all extra cost and build a stock-stroke 360), but there are a good few combos out there making extreme work on the street.
I had a good friend that used to street-race his ratty 73 Maverick. He'd built a nasty little 289, much like the two above examples (big aluminum heads, big modified intake, stupid-big solid cam. It had everything but compression (he was a real cheapass and bought swap-meet pistons) and made over 400HP. Thing had 4.56's and he'd drive that thing to work every day, 30 miles down the highway, and he'd never be anywhere close to the speed limit. At one time he'd covered the same commute at around 100mph, over 5000 rpm the whole way. Summer, winter, rain, snow, camping trips, road trips... that thing went everywhere. He couldn't convince anyone on the street it wasn't bottled when it raced, and would rather pay for all that extra gas than install an overdrive or more 'daily' gears. An extreme example, and after 3 years ov this he did finally tire ov the maintenance (and inability to clear speedbumps), but the screamers can be made to work, and live well. Apple, meet orange, sure... but a fun story anyways.
Posted By: polyspheric
Re: 450 horsepower 318?? - 03/16/13 05:41 AM
2-7/8" stroke
Posted By: FastOne
Re: 450 horsepower 318?? - 03/16/13 05:59 AM
Darn Dart 1995, ET 10.86 @ 114 mph, 273ci, 340 X heads, notched bores, TRW 11.5.1 comp, 509 hydraulic, 4500 stall, 5.50 gears, Cyclone headers, car 3,000lbs, 345 HP
Posted By: moper
Re: 450 horsepower 318?? - 03/16/13 08:55 PM
Just so I'm clear - you want big horsepower and you knwo it takes good parts as far as everything else but the block - but a 340 block is too expensive? You're a bracket racer - it should be pretty clear that the more crazy you get with an engine the harder it is to be consistent - which is really what bracket racing is about. So - if you need that power, build the biggest small block you can and don;t work it as hard. That would be my advice. An LA 360 based 408.
Posted By: mopar65
Re: 450 horsepower 318?? - 03/16/13 09:48 PM
Quote:
Just so I'm clear - you want big horsepower and you knwo it takes good parts as far as everything else but the block - but a 340 block is too expensive? You're a bracket racer - it should be pretty clear that the more crazy you get with an engine the harder it is to be consistent - which is really what bracket racing is about. So - if you need that power, build the biggest small block you can and don;t work it as hard. That would be my advice. An LA 360 based 408.
there is a very nice looking 422 stroker small block in the race parts for sale section that would be right up hi alley.looks like all it needs is a set of hearers and you would be ready to go. i do not know the member that is selling it so this is not a sales pitch for him. but if i had the money i would buy it. mopar65
Posted By: Belvedere2
Re: 450 horsepower 318?? - 03/17/13 12:17 AM
Quote:
Quote:
Just so I'm clear - you want big horsepower and you knwo it takes good parts as far as everything else but the block - but a 340 block is too expensive? You're a bracket racer - it should be pretty clear that the more crazy you get with an engine the harder it is to be consistent - which is really what bracket racing is about. So - if you need that power, build the biggest small block you can and don;t work it as hard. That would be my advice. An LA 360 based 408.
there is a very nice looking 422 stroker small block in the race parts for sale section that would be right up hi alley.looks like all it needs is a set of hearers and you would be ready to go. i do not know the member that is selling it so this is not a sales pitch for him. but if i had the money i would buy it. mopar65
Yep been looking at that for months. If I didn't already have my 380 that bad boy would be mine. Gotta love torque!
Posted By: B3422W5
Re: 450 horsepower 318?? - 09/19/14 06:38 PM
Quote:
FWIW, several years ago, in Engine Masters, a Adney Brown of Precision Crankshaft built an iron headed 318 that made 477hp at 6500rpm; that was the top of the pull, I suspect it would have kept going a little more. I have the copy of "Popular Hot Rodding" that featured the build; I'll look for it.
It's written up in the January 2009 issue of "Popular Hot Rodding", the high lights: .030 over, Diamond pistons, Comp solid flat tappet, [Email]247@.050[/Email] I & E, 1.7 Harlen Sharp intake rockers, Crane 1.6 exhaust, ported Magnum R/T heads(used super stock cast off's), Chinese air gap, 950HP Holley, 10.44 compression.
I ended up buying that motor and had it in my car at Norwalk. It currently has a much smaller hydraulic cam in it( 231@50) instead of the 247 solid from the Dyno sessions.
Car weighs 3415 and went 113.37 mph@ 11.79 with it, basically little tuning on it( know the carb is currently wrong). Shifted it at 6200, trapped at 5900. Would like a 4.56 gear vice the 4.10 I have in it, but it's mainly a street car.
Car has power steering, factory water pump and clutch fan. Based on the car weight and mph, it's already been a tenth quicker than what Wallace calculator figured. I put in 460 ponies based on the accessories it's running and came up with an 11.90.
Posted By: GY3
Re: 450 horsepower 318?? - 09/19/14 07:15 PM
Pfft, buy a low mileage $300 motorhome 440, do rings, bearings and a fresh valvejob on the heads. Cam, headers and intake will get you there without breaking a sweat with stock parts. Best of all you can bolt on heads and do a stroker kit for another easy 150-200 HP in future upgrades!
I went down this road with a 318 and, in the end the BB was cheaper, faster, easier to service and much more capable!