Making power out of the 318

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dirty white boy said:
zero deck the block, shave heads to desired compression with the flat tops! id run a mechanical 650 on a single plan if mostly race,..for street id run a 750 on a airgap! cam and matched converter, street gears 3:55 to 3:91 race 3:91 to 4:88s depending on 1/8th or 1/4!
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Ok why do you say flat tops not a dome piston? because some of the forms i have read say the domes are the best for the 318 i am just curious
 
Yup. Like I thought. Domed pistons and 400HP with 3K bucks. Ain't happenin. Cya.
 
RustyRatRod said:
What I would shoot for would be 325-350HP. Very reasonable goal and you should be able to get there with your budget. The Hughes Whiplash cam for the 318 would sound good. But remember, then you'll need a matching converter and better gears. More money. I'd concentrate on power output instead of sound.
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That is a very good idea to concentrate on power instead of sound. I never thought of that and that’s a good way to put it. But I’m really trying to shoot for 400.
 
carmart1975 said:
I really like your thinking I was planning on buying a new transmission not a used one and it would be a built trans anyway so maybe I could find one with the lower gears
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998/999 have a lower 1st gear. and if you can rebuild an engine you can do a trans.

but I will most likely be switching over to a eight and three-quarter rear end later down the road after this one shreds
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it will be sooner than you think! bank on that.

What if I use stock 318 heads and do a diy port job on them? Because I have those sitting in my garage. They’re the ones that came with the motor, but he also gave me those 360 heads. But if I was to stick with any of the heads, have to get completely redone because they have gunk and stuff like that so I would have to get new valves and all that stuff anyway but I just don’t know how much this machine work is going to cost I’m very new to the stuff. My dad hasn’t done this kind of stuff and 30+ years also
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i'd probably go with the 360 heads in that they're likely to have larger valves and flow better than whatever 318 heads you have. unless the 318 heads are minty and don't need work. but, yes, port away. (more on heads later)

machine work has become very expensive. finding a competent machine shop these days is also difficult.

carmart1975 said:
I like the idea of a magnum 360 in fact my dad‘s friend suggested that, but I just could not find any in my area let alone within 200 miles and I got a really good deal on this 318 so I would like to use it and most likely I’ll yank it and either stroke it later down the road or put a 360 in
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where are you in CA? there are TONS of magnums in the yards and on c'list, etc.

okay, all that aside, here's what i would suggest. rebuild the bottom end with good slugs and aim for 9.5:1 compression. then, spend your money on heads. you *could* go magnum, that's probably the cheapest bang for the buck, but will require custom pushrods and hustling up all the bits and bobs. maybe you score a deal on some big valve 360 heads that don't need a billion dollars worth of work or somebody is unloading a set that got breathed on because they upgraded to something else. used alum. edelbrock heads show up in the classifieds here from time to time.

legit, you're probably going to spend 1/3 of your budget on heads.

so you've got 500 in pistons, 300 in rings & bearings, 200 in gaskets. then tack on 500 for cam, lifters, timing chain, pushrods. throw around another let's say 300 in misc argle-bargle of oil pump and pick up, maybe the correct oil pan, fuel pump, etc.

so you're 1800 into the bottom end, another 1K uptown, and you've got 200 to figure out: intake, carb, spark, ticky-tacky stuff like valve covers, air cleaner, oil filter adapter, thermostat and housing, pulleys, etc, etc, etc.

if you're working within such a tight budget, remember that everything is a compromise. decide where that compromise is going to happen.

also, keep in mind that besides the transmission you'll likely need to upgrade the cooling system at a minimum, figure out motor mounts, exhaust, minor electrical, as well as brakes and suspension
 
carmart1975 said:
That is a very good idea to concentrate on power instead of sound. I never thought of that and that’s a good way to put it. But I’m really trying to shoot for 400.
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Then you'll have an easy 3K tied up in machine work. Then there's head porting, or aftermarket heads. This is a 5-7K or more engine you're talking about.
 
junkyardhero said:
998/999 have a lower 1st gear. and if you can rebuild an engine you can do a trans.


it will be sooner than you think! bank on that.


i'd probably go with the 360 heads in that they're likely to have larger valves and flow better than whatever 318 heads you have. unless the 318 heads are minty and don't need work. but, yes, port away. (more on heads later)

machine work has become very expensive. finding a competent machine shop these days is also difficult.


where are you in CA? there are TONS of magnums in the yards and on c'list, etc.

okay, all that aside, here's what i would suggest. rebuild the bottom end with good slugs and aim for 9.5:1 compression. then, spend your money on heads. you *could* go magnum, that's probably the cheapest bang for the buck, but will require custom pushrods and hustling up all the bits and bobs. maybe you score a deal on some big valve 360 heads that don't need a billion dollars worth of work or somebody is unloading a set that got breathed on because they upgraded to something else. used alum. edelbrock heads show up in the classifieds here from time to time.

legit, you're probably going to spend 1/3 of your budget on heads.

so you've got 500 in pistons, 300 in rings & bearings, 200 in gaskets. then tack on 500 for cam, lifters, timing chain, pushrods. throw around another let's say 300 in misc argle-bargle of oil pump and pick up, maybe the correct oil pan, fuel pump, etc.

so you're 1800 into the bottom end, another 1K uptown, and you've got 200 to figure out: intake, carb, spark, ticky-tacky stuff like valve covers, air cleaner, oil filter adapter, thermostat and housing, pulleys, etc, etc, etc.

if you're working within such a tight budget, remember that everything is a compromise. decide where that compromise is going to happen.

also, keep in mind that besides the transmission you'll likely need to upgrade the cooling system at a minimum, figure out motor mounts, exhaust, minor electrical, as well as brakes and suspension
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Thank you so much for the breakdown like that that really helped. I can really tell that this is gonna take a lot more money. And what do you mean for the trans 998/999, I am in the SoCal area. But I cannot find any junkyards for the life of me. As far as cooling system,I already have a really high-end aluminum radiator will be putting electric fan on it exhaust is covered I can do myself I have everything for that and i will get some cheap mufflers. Is there anyway i can send you a pic if the 360 head and you can tell me what i have if you know i have look all over the internet and i cant get a straight answer, I can tell you spent a lot of time doing this for me thank you
 
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RustyRatRod said:
Then you'll have an easy 3K tied up in machine work. Then there's head porting, or aftermarket heads. This is a 5-7K or more engine you're talking about.
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Ok i have a question if you had 3k and wanted to make 400hp what you you do
 
Don't have to do everything on day one.
If doing a rebuild do the best short block you can afford that's built around future plans.
Like a zero decked short block, if the top end is a little miss matched, it's ok it's only temporary, down the buy a set of good aftermarket heads etc.. as you go and can afford it. Or find a decent usable short block and spend money on top end.
 
carmart1975 said:
Ok i have a question if you had 3k and wanted to make 400hp what you you do
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I live in Canada our money doesn't go as far. But I'd start with a decent running magnum preferably 5.9l (360) but a 5.2l (318) will work cause they got decent cr and head is capable to make 400 hp as is with a reasonable cam, on the high end of reasonable. A little port work and maybe some milling get away with less cam and or make more power and can always do an aftermarket head swap down the road for more power.

Price out the various ways to get there pick best one that suits you.
 
carmart1975 said:
Ok i have a question if you had 3k and wanted to make 400hp what you you do
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5.9 magnum, 500 lift 280 duration cam, home ported stock heads, eddy air gap, 750 carb, headers
(there's a limit to how much you can go over .500 with magnum heads before coil bind and expensive aftermarket keepers + keepers or machine work enters the chat so keep that in mind)

but that should be darn near 400 on the money

wanna make it with less cubes? better heads and more compression.
 
carmart1975 said:
Ok thank you, by chance do you know of a good cam that i could use with a nice lope i really want a bang for you buck cam if that is possible
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i do not understand the trend of why everybody all of a sudden wants to buy cams based on how they sound.

who gives a rat's patootie what it sounds like! how it runs is far more important unless you spend your time idling around the fairgrounds or revving your nuts off in burger joint parking lot.

there's no one answer to which cam to use. there are general recipes that are accepted as combos that work well together, or some rules of thumb, and ideas and suggestions. but you need a lot of additional information to make an informed decision.

bang for the buck is choosing the right cam for the combo the first time and not buying one all willy-nilly, finding out that it sucks, hating life when you have to drop that loot and do it all again.
 
RustyRatRod said:
What I would shoot for would be 325-350HP. Very reasonable goal and you should be able to get there with your budget. The Hughes Whiplash cam for the 318 would sound good. But remember, then you'll need a matching converter and better gears. More money. I'd concentrate on power output instead of sound.
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this. 100% this is absolutely great advice. spoken like a true pro.
 
carmart1975 said:
Thank you so much for the breakdown like that that really helped. I can really tell that this is gonna take a lot more money. And what do you mean for the trans 998/999, I am in the SoCal area. But I cannot find any junkyards for the life of me. As far as cooling system,I already have a really high-end aluminum radiator will be putting electric fan on it exhaust is covered I can do myself I have everything for that and i will get some cheap mufflers. Is there anyway i can send you a pic if the 360 head and you can tell me what i have if you know i have look all over the internet and i cant get a straight answer, I can tell you spent a lot of time doing this for me thank you
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go here and drop in your zip code: Quality Discount Auto Parts | Salvage Yards | LKQ Pick Your Part

c'list, offer up, farkbook, classifieds here, swapmeets. the parts are out there, it's just a hustle to get them.

you can attach pics to the message bodies here in thread. "attach photos" or thru external link (imgur). but if you provide the PN off the heads (it's on the runner in between the valve springs) you can google that or somebody here can tell you what they are. measure the valves tho, a lot can change in 40 years.

there is an absolute TON of info here, the search function is decent if you're specific in the query but you can get better results with an enhanced google search {how to pick a cam for a 318 forabodiesonly(dot)com} will turn up excellent results.

sorry if we come off a little gruff, but we know the realities of the game and we hate to see people waste hard earned money and invest blood sweat and tears into something that's a mistake we've all made before.

i don't know how far you're into that 318, but if it's not a boat load you might be better off packing that in and trying to get a few doubloons for it and pivot over to 5.9 that would likely be cheaper and easier to reach your 400hp goal.

i love 318's and i think they're fun builds, but if you want to make big power for cheap, you need to start with cubes and the magnum has the added benefit of great flowing heads.

that being said, a 300hp 318 in a light a-body is a blast. and that's doable on a beer budget.
 
273 said:
If I was you, find a decent running 5.9l magnum add a airgap and headers, and a cam similar to the 288/296 230/2xx .500" 108. Create cam made 400-410 hp. A 212/218 .480 114 made 350 hp so somewhere around there.
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Red "x" time, no "run a 360" please. He asked about building a 318....
 
volaredon said:
Red "x" time, no "run a 360" please. He asked about building a 318....
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He also asked to make 425 to 500 hp on a 3k budget now 400 hp on a 3k budget with 3.21 gears and a 318. He also asked what we would do to make 400 hp with 3k, I'm for 318 builds but sometimes people are asking the engine to be too many things. I've made suggestions on many different ways to try to accomplish his goals and 360 only being one of them, if he doesn't want to go that way fine like one of my signatures says "If your willing to gear it build it if not build a larger displacement, Or take solace in your compromises." People just don't seem to get how important gears are to smaller displacements not as important than a good stall but up there.
 
He's 15. I don't know if he knows what it's like to have a "400hp" anything... especially being he isn't even legal driving age yet... Having not yet experienced much "drive time" I'm betting he'd be happy with 275-300 hp. Numbers sure sound good but he can't really know...
 
First thing is to figure out what you have, casting numbers, how much is the block bored now and where will it clean up. What head castings do you have, find the numbers. What condition are the parts? Can you get just one piston? Before you spend any money, magneflux the heads you want to run and find what is the smallest bore that the block will clean up? Now lets get real. Run what you got. We are talking street car, young man, everyday driver, pump gas and decent mpg so he can afford to drive it. You basically want to build a 1972, 9 to high 8 to 1 compression ratio 340 with a 318 block. Forget horsepower. Get the pistons you first thought of if you need to bore the block. Use the 360 heads. Get a hydraulic cam and lifters somewhere in the .450 to .500 lift and 210 to 225 duration at .050 and a double roller timing chain. Find a used 340 intake, then go with a carb to fit the intake. Have the distributor recurved for high performance. Add a windage tray and high pressure oil pump relief spring. Balance the pistons, rods, and crank. 8 1/4 rear will be fine and the 3.21 gears are perfect. No need for low first gear trans, find a decent used 904 or 998 and get that car running and Enjoy.
 
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I would build a good bottom end with a set of flat tops level with the deck.

id build that bottom end with main studs and wavelock rod bolts
id balance the bejeezus out of it crank and balancer, rods end to end, rod pin and piston weight if i had the option id choose the best set of 8 rods out of 2 motors small end in the middle of the small end casting etc not the gnarly looking, wonky 2 you find in each set

id use the King bearings race bearings
id do all the core/freeze plugs
i'd build it with clearances in middle of the tolerance
Id get a good harmonic balancer a known brand
id get a romac timing set, IWIS roller chain, a timing set where i can trust that the keyways and dots will be where they should be....! with some of the other big names you can't
i might..... put in a windage tray or a crank scraper
id match port my oil pump to the block
i'd make sure my pickup was solid
id put in a sump baffle
id measure exactly the required quantity of oil into that sump and make sure my dip stick read just below max. pull out and re site the dipstick tube if necessary
i'd have a new water pump
i'd bluprint my stock oil pump
new piston and relief spring
new senders
i'd paint it nicely
id tumble and clean up the chrysler hardware the screws with the "lead into the threads" so putting on sump and fuel pump is easy
id get either a rebuilder orginal carter pump and rebuild it or a new carter pump

changing the rod bolts means you have to have the rods resized and checked...
studs and rod bolts torqued to ARP spec not standard bolt spec
id run a clutch fan and standard alternator. its too easy to buy a **** electric fan set up

Id bolt on the 318 heads and a 4bbl inlet
id use the cast iron exhaust manifolds and id merge the collectors way back
id put in a standard dizzy and cheap HEI set up i.e mid 70s chevy 6 truck coil + and napa hei module
dizzy will potentially need a recurve

and see how it goes

the small valve 318 heads combined with the higher CR from the zero deck pistons and a small 600cfm carb will give you a wide torque curve that is just gooood fun around town...

once this is done you can do what ya like with cam heads inlet in future
and you can plan and save all while driving the car, cruising and going to shows

short block done ready for its next upgrade is a good place to be
and you have a benchmark to measure your upgrades against
what does good look like and what is better.... if you don't know you can't assign a bang for buck value to your upgrades

dave
 
3K for a budget is not a lot of money at all and the need for a transmission is going to eat half of that.
 
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