how can i get 400hp out of a 318?

SRT_DSTRHOLC · Oct 5, 2011

kb167
Magnum heads
xe274
air gap intake
holley 750 vac
1 5/8 headers

or read the CC article where they made 400hp

jerry6 · Oct 5, 2011

crackedback said:
Call me skeptical, but, I don't see any of those magazine 400hp/318 builds powering a 3200-3300# car to about 110-112mph in the 1/4, which a true 400hp engine should do.

A 318 at 400hp is going to have a really nasty cam in it, some compression and good heads ( not valve jobbed 340-360 pieces). JMO.

Have to agree , that's the range my car runs and I know it's at least 412 hp . Somehow these magazine cars never run near what they should for the torque and hp they claim .
Agree on the 318 build as well ,or you could go the supercharger route , forged 9:1 pistons , forged crank , balanced with a good set of heads and you will be at or over 400hp and RELIABLE .

mopardude318 · Oct 5, 2011

i think 400 hp from a 318 is pretty attainable....10:1 comp, rpm air gap, roller rockers, RHS heads form brian, good solid flat tappet cam, and a solid bottom end should do it..

for my 318, I would absolutely LOVE to have a 3.79 inch crank...anyone know where to get one?

JoeDust451 · Oct 5, 2011

Fst73_360 said:
kb167
Magnum heads
xe274
air gap intake
holley 750 vac
1 5/8 headers

or read the CC article where they made 400hp

Haven't you learned people on these boards don't read, they just know more then the guys that "actually" build engines & test them, I read those acticles & 400hp was easily doable with a "stock stroke" 318, they even said how they proved the sceptics wrong, oh yeah there again, the ones that hardly ever build engines & spend 24/7 on these boards & know everything....

crackedback · Oct 5, 2011

There's a reason none or very few of those mag engines tested at westech ever end up in cars to prove out the claimed HP.

Seen two that were tested at westech, then the next day at another facility. Both engines at the other facilities were 10-18% light on the westech numbers. They ran like the lower hp numbers. Westech was infamous for exaggerated numbers. In the words of a respected engine builder in the LA area... big dyno numbers sell engines, regardless of how they actual run. Look no further than the blown 600+ hp 318 that mph'd in the high teens in a 3500 pound car. 475-500hp cars mph there at 3300.

Build one of those engines and find out what they make, more importantly, how they MPH.

Have fun.

needsaresto · Oct 5, 2011

A true 400 h.p engine will haul the mail and show in the e.t, but only if the rest of the drivetrain is taken care of as well. The transmission,converter,rear gear and all the suspension need work before the car will e.t to it's potential.

You can throw all the money you have at the motor but if the rest of the car aint set up your gonna get your *** handed to ya!

waggin · Oct 5, 2011

good read....lol them guys that wrote the two diffrent articles are chevy guys and they are actually pretty happy with the lil' 318 and the power they got out of it....there is more to be gotten but they only had the dyno for a day,bottom line was they built one and werent dissapointed,i've put bolt ons to them lil motors over the years just because It was what I had to work with and was never unhappy with their performance.....if I would have spent some money on pistons and machine work i'm sure I wouldn't be upset......it's just a lil' 340....rev it !

JoeDust451 said:
Haven't you learned people on these boards don't read, they just know more then the guys that "actually" build engines & test them, I read those acticles & 400hp was easily doable with a "stock stroke" 318, they even said how they proved the sceptics wrong, oh yeah there again, the ones that hardly ever build engines & spend 24/7 on these boards & know everything....

crackedback · Oct 5, 2011

needsaresto said:
A true 400 h.p engine will haul the mail and show in the e.t, but only if the rest of the drivetrain is taken care of as well. The transmission,converter,rear gear and all the suspension need work before the car will e.t to it's potential.

You can throw all the money you have at the motor but if the rest of the car aint set up your gonna get your *** handed to ya!

Absolutely correct, ET is chassis/converter/gear/etc.

MPH will tell you the story on engine HP. Ever seen cars run crazy MPH for the et? Like 14.30 at 105 ( could be 12.50-12.70), high 11's at 130 (10.10ish), 11.20 at 128 (10.40-10.50). Those numbers reflect a rotten chassis with a decent engine hp.

cowboyup1107 · Oct 5, 2011

Kieth black 167 flat top pistons, block zero decked w/ minimal milling, .040 over makes it a 324cid, factory cast crank, recondition rods with pioneer bolts. factory windage tray, 360 smog heads, heads machined for 2.02 intake valves, bore notches, heads milled heavilly to 60cc, Comp xe275HL 231/237 degree duration @ 0.050-0.0525 lift on a 110 degree lobe seperation angle, Comp 972 single springs installed @ 140 lbs on the seat and 310 lbs over the nose, 800cfm carb, tti headers w 1 5/8 to 1 3/4 primaries, 1" open carb spacer, 1.5:1 ratio rockers, and 5/16 pushrods. Makes +/-415hp

Rat Patrol · Oct 6, 2011

dodge freak said:
I know, you think if it was so easy the factories would had stroke the engines years ago and skip building big block engines. What did the factories do, they built the engines for rpm's with forged cranks and pistons. Ford had the 302, Chevy had the 327 and Mopar had the 340, all built to handle rpm's.

U need good heads, ported for sure. Maybe the RHS? forget the small port heads the engine needs to breath.

I would try for 10 to 1 compression and a solid cam for rpm's Comp Magnum 280 has been around for ages and works well. With a high stall converter it drive around town just fine.

You're missing the point on the issue of strokers -

The point of choosing the stroker route is simply to arrive at a more versatile and less temperamental SB engine for a target HP..........so your comments are irrelevant.

The OP didn't specify what type of "duty" the engine was going to see -Or did I miss that?:scratch:

I'm guessing most engine builders would know from running a three speed trans auto on the street - anything you can do to lower converter stall, compression, increase torque at a given RPM and smooth out cam lope is a win on a hot stinking day in Arizona in work day traffic.

However - I'll play the game.............If it's a race car - go nuts.....I recommend the short stroke, steel crank, Carillo roads, 13:1 comp and Avgas and ported 360 / RHS heads and 1 &7/8 TTIs. LOL!!!

You still could build a strong running 318 that can take on these "400 hp" new cars today. But yeah nasty cam, heads and gears in the 4 range is needed.

I agree on the "nasty cam" - thats why I suggested a stroker build.....I won't mention "4+" gears because thats irrelevant to the target HP. :toothy1:

Bill Dedman · Oct 6, 2011

Rat Patrol said:
You're off beam on the issue of strokers -

Nobody with any intelligence would say that a stroker is going to make more peak HP than a std stroke block using identical compression, heads, induction and camshaft.....what works for the std stroke will starve the stroker - not that anyone would build either motor the same way anyhow.

The point of choosing the stroker route is simply to arrive at a more versatile and less temperamental SB engine for a target HP.

The OP didn't specify what type of "duty" the engine was going to see -Or did I miss that?

I'm guessing most engine builders would know from running a three speed trans auto on the street - anything you can do to lower converter stall, compression, increase torque at a given RPM and smooth out cam lope is a win on a hot stinking day in Arizona in work day traffic.

However - If its a race car - go nuts.....I recommend 13:1 comp and Avgas with Eddie heads and 1 &7/8 TTIs.

XXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXX

I put an ebay ($1,000.00) Vortech supercharger on a 360 Magnum that had been treated to a set of TTI headers, an air-gap Chinese clone intake manifold and a Hughes cam. Those are the ONLY performance pieces on the otherwise BONE STOCK engine. It makes 10 pounds of boost.

The blower took it from a 13.35/102mph to mid 11s @ about 117. Made a different car out of it...

There was no "KIT" so I did all the necessary mounting stuff, myself. It was frustrating, but fun, too.

Here is the dyno sheet from a local \chassis dyno, and a coupe of pictures...
If you believe the 85-percent for the chassis dyno figure formula, it makes 525 flywheel hp.

Anyone with a 318 could do the same, with only minimally smaller output, I think. JUst an alternative to a big cam and high compression...

Rat Patrol · Oct 6, 2011

cowboyup1107 said:
Kieth black 167 flat top pistons, block zero decked w/ minimal milling, .040 over makes it a 324cid, factory cast crank, recondition rods with pioneer bolts. factory windage tray, 360 smog heads, heads machined for 2.02 intake valves, bore notches, heads milled heavilly to 60cc, Comp xe275HL 231/237 degree duration @ 0.050-0.0525 lift on a 110 degree lobe seperation angle, Comp 972 single springs installed @ 140 lbs on the seat and 310 lbs over the nose, 800cfm carb, tti headers w 1 5/8 to 1 3/4 primaries, 1" open carb spacer, 1.5:1 ratio rockers, and 5/16 pushrods. Makes +/-415hp

MPH and weight?

Heads ported?

Rat Patrol · Oct 6, 2011

Bill Dedman said:
XXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXX

I put an ebay ($1,000.00) Vortech supercharger on a 360 Magnum that had been treated to a set of TTI headers, an air-gap Chinese clone intake manifold and a Hughes cam. Those are the ONLY performance pieces on the otherwise BONE STOCK engine. It makes 10 pounds of boost.

The blower took it from a 13.35/102mph to mid 11s @ about 117. Made a different car out of it...

...

No argument from me Bill -

This was my engine builder's twin turbo 318 -

630 FWHP running a 282 advertised duration camshaft and mild 360 cast heads - but the plumbing scares the beejeesus out of me!

rayer:

moper · Oct 6, 2011

It's no harder to get 400hp from a 318 than a 340. They even behave the same way. The issue is peak and peakiness of the torque curve. These two tend to be higher for peak, and peakier in terms of the overall operating range for a high horsepower, short stroke engine. But it's not hard to do. The factory 318 heads are a little restrictive for that goal, but any 340/360 head, or better yet the Magnum based aftermarket heads, performance pistons, and a hydraulic cam and it can be done. It will just need to be paired with at least a 3-series rear gear and some sort of convertor, because the torque will be higher up the rpm range, and not as flat a curve.

Bill Dedman · Oct 6, 2011

Rat Patrol said:
No argument from me Bill -

This was my engine builder's twin turbo 318 -

630 FWHP running a 282 advertised duration camshaft and mild 360 cast heads - but the plumbing scares the beejeesus out of me! rayer:

I did what I did because I am no welder, and a turbo would have necessitated a fair amount of fabrication (involving welding) that I side-stepped wwiththe belt-driven blower. I would have preferred a single turbo setup, but just didn't have the necessary skills.

Our turbo '6 project will satisfy those urges,hopefully.:cheers:

BTW, my supercharged 360 is in this 72 Valiant 4-door and weighs 3,340 pounds, without the driver...

needsaresto · Oct 6, 2011

crackedback said:
Absolutely correct, ET is chassis/converter/gear/etc.

MPH will tell you the story on engine HP. Ever seen cars run crazy MPH for the et? Like 14.30 at 105 ( could be 12.50-12.70), high 11's at 130 (10.10ish), 11.20 at 128 (10.40-10.50). Those numbers reflect a rotten chassis with a decent engine hp.

Yep,see that all the time. It's usually a stocker with a hot cam and good heads...

needsaresto · Oct 6, 2011

the plumbing scares the beejeesus out of me!

rayer:

Aww come on..the plumbing is no worse than Bill's wiring,lol..

Bill Dedman · Oct 6, 2011

needsaresto said:
Aww come on..the plumbing is no worse than Bill's wiring,lol..

Hey; it runs, and nobody's gotten electrocuted.... yet.:sad11:

JoeDust451 · Oct 6, 2011

Bill Dedman said:
XXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXX

I put an ebay ($1,000.00) Vortech supercharger on a 360 Magnum that had been treated to a set of TTI headers, an air-gap Chinese clone intake manifold and a Hughes cam. Those are the ONLY performance pieces on the otherwise BONE STOCK engine. It makes 10 pounds of boost.

The blower took it from a 13.35/102mph to mid 11s @ about 117. Made a different car out of it...

There was no "KIT" so I did all the necessary mounting stuff, myself. It was frustrating, but fun, too.

Here is the dyno sheet from a local \chassis dyno, and a coupe of pictures...
If you believe the 85-percent for the chassis dyno figure formula, it makes 525 flywheel hp.

Anyone with a 318 could do the same, with only minimally smaller output, I think. JUst an alternative to a big cam and high compression...

Damn, just noticed that wiring job, I though I was bad :violent1::glasses7:

RustyRatRod · Oct 6, 2011

JoeDust451 said:
Haven't you learned people on these boards don't read, they just know more then the guys that "actually" build engines & test them, I read those acticles & 400hp was easily doable with a "stock stroke" 318, they even said how they proved the sceptics wrong, oh yeah there again, the ones that hardly ever build engines & spend 24/7 on these boards & know everything....

Some people, such as myself, are here "24/7" because of a disability and it keeps them sane. I'm sure you didn't mean that as insulting as you made it sound. I was a mechanic for almost thirty years and got hurt and now can no longer work. Although I've not built many engines lately, I assure you the ones I have built number over 100. And disassembly even more since I started as a kid in a local machine shop at the bottom rung.

needsaresto · Oct 6, 2011

StrokerScamp said:
Some people, such as myself, are here "24/7" because of a disability and it keeps them sane. I'm sure you didn't mean that as insulting as you made it sound. I was a mechanic for almost thirty years and got hurt and now can no longer work. Although I've not built many engines lately, I assure you the ones I have built number over 100. And disassembly even more since I started as a kid in a local machine shop at the bottom rung.

True dat my friend. I havent built even 10 myself,more like 5 myself,and 3 with help when I was younger. And thats all V8's,not including the 5 yrs of small engines I built and serviced.

Here for the same reasons as stroker,allthough different circumstances in my case.

I took no offence at the know it all remark,as I know that NO-ONE can possibly know all,lol!!!

Me personally I think 400 h.p from a teen is no problem and achievable with over the counter parts.Heck even 700 h.p is do-able if your pockets are deep.

It's choosing the RIGHT parts combo that does the trick.

cowboyup1107 · Oct 6, 2011

Rat Patrol said:
MPH and weight?

Heads ported?

idk not built yet by me. was a previous build for someone else. I will be doing this in febuary. its a hold me off til I can build my 414 stroker:thumrigh:

cowboyup1107 · Oct 6, 2011

BTW rat patrol that is a gnarly looking setup you have. cant even tell its a 318. how much if you had to guess is tied up in that build?

bohica2xo · Oct 7, 2011

Depending on what the OP wants to do with his 400 hp, a turbo may make perfect sense. Daily driven reliability, the ability to turn the performance up or down, run garbage gas if you need to etc.

400 horsepower is single turbo territory. It does not need to be complicated. I designed & built the system for the SB chebby below in 1978. We used a target motor straight from the dealer, baselined it on the dyno @ 190 hp with a smog legal Quadrajet & 1978 distributor set @ 5 ATDC.

With 6 psi from a single Rajay turbo, we could get 450 ft/lbs all the way to about 4400 rpm - which is 375 hp in anybody's dyno room. Stock smog cam, draw through the OEM Quadrajet. Smog legal components & timing. Easily the worst cast piston made in mexico junk GM ever made. 375 horsepower. Drove like a stock engine unless you opened the secondaries.

It worked well. I still see them for sale on e-bay occasionally 30+ years later like the example below. Making a system for a 318 in an A body would mean making or modifying a passenger side exhaust manifold to mount a properly sized turbo. Really the hardest part of the fabrication comes down to that one manifold.

B.

Rat Patrol · Oct 7, 2011

cowboyup1107 said:
BTW rat patrol that is a gnarly looking setup you have. cant even tell its a 318. how much if you had to guess is tied up in that build?

Not my build Cowboy..my engine builders ex- rig. (Mine's just a low 12 sec 392 stroker.)

I wouldn't like to comment on cost as its not my engine.

A lot of the fabrication was done by a mutual friend who has now passed on (ex Nascar mechanic) - Runs a Wolf 3D EFI and Twin master power turbos which is where the $$$ are.

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