Better Torque From A 318

[273]

What power level you trying to get?

Sounds like streetaability is important to you so probably 0.8 to 0.9+ hp per cid about 256-290 hp.

Not really that hard there's slightly different ways to get there, mainly different head and cam combos, less flow more cam, more under .450/.500" flow less cam. Bigger cam is gonna be less streetable than better heads.

Say you decide 9:1 4bbl headers and a 210 cam then stock heads be it 318 or 360 or magnum or speedmasters or some ported version of them is gonna decide hp amount.

 

[Dan the man]

I've got a 3.9 NV2500, 3.90 8-1/4 that's going to be upgraded sometime... but I love it the way it is too much right now! I've converted it to manual steering and electric fan, and it can do a 120 mile round trip on less than 6 gallons of fuel throught the mountains and a 1,000 pound load on the way back... no need to mess with perfection yet!

I agree

 

[3forty]

[FOR SALE] - 1970 Dodge Dart Swinger 340 4 Speed

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www.forabodiesonly.com

Fly in,drive home.

 

[273]

Probably best off buying a car close to what you want.

I bought mine street legal, solid body decent interior with a 380 hp create engine built 727 with and a 8 3/4. $9500 CAD cause I wanted driveable car with a solid foundation that still needed to work that I can do weekend projects on.

 

[rumblefish360]

I knew that I shouldn't have asked anything.

No, you should.

Toolmanmike, please go ahead and remove this post. Thanks

Sounds like you don't believe in others asking questions.

He won’t delete the thread.
It’s not that questions shouldn’t be asked but it’s the amount of questions and the OE poster, (You!) nit picking, slicing and dicing replies, splitting hairs on issues while constantly turning down cars that are pretty darn nice to start with.

Then you re ask your questions later with different words expecting a different answer. I haven’t seen anyone here NOT try and help you at first but only get tired of the tire kicker (You) when the same old pattern reappears time again and again.

Dan! Straight up! We all want to help but if you’re not willing to get into the pool, we really can’t teach you how to swim. Just talk about it. We have all been talking about it for a long time. It’s time you just simply get in the dang pool and learn how to swim and it would be good to do so before global warming dries the pool up.

You probably were the best help. Thanks

This advice is very good and has been given to you several times and several times by myself alone.

Let me help you!

Do the following first and foremost before you do ANYTHING else!






























































Get a car.

 

[rumblefish360]

Are you doing this with one of the mopar 3.4-3.5 inch cranks and some 1.80ish compression height 340 pistons?

The rotating assembly is a MP 3.45 forged 8 bolt crank with the flat top MP forged pistons set at a positive deck height of .018. The MP con rods were shelved because they were in a OOTB condition. Which means they weight a hair more than the stockers, were in need of finishing to a lighter weight and balanced. While the rod could have been used as is, it was just more work for the machinist and that’s time and money I did t want to spend and to be honest, the machinist said he would rather not do. Even more so since I had some Eagle forged rods ready to go.

This rotating assembly is designed for a small main block, which I don’t have for the kits piston size of 4.03. I used a 360 block and main bearing spacers from Bill Richardson which allows the small main journal crank into the large journal 360.

Total cubic inches are 352.

The cylinder head for use will be varied for some dyno testing and experiments. Same with camshafts. The only thing I’ll let loose at this time is the following cylinder heads available for fun.

Stock 1.88 J, Promaxx CNC, Hughes Big Mouths, W2, W5.
I’ll be working on a set of ported J heads I’ll port myself later & I’m playing with the idea of just simply equipping another set of W5 with gear and running them without porting them.
Just to see what they do.

You’ll have to watch my YouTube channel for future actions, experimentations and engine builds.

I don't recall having seen any postings on that particular engine before, but I apologize if I have...

No worries, I have only mentioned it in passing.

I've recently joined the positive deck club, I've currently got an above deck 340 inch combination that I'm contemplating on the parts to complete.

I also have a 340 that I had the KB domed (replacement) piston installed. My instructions to the machinist were to have the major area of the flat portion of the piston at zero deck which should give a stock height some positive position.

The Promaxx CNC’d heads are on top of that now along with a RPM AG, AFB 750, standard headers, 1.5 roller rockers and a XE285HL that I asked Comp to modify to a 108 LSA.

Both of these positive deck height list ones engines are not what I’m used to working with. Normally I used a zero deck flat top. So this is a learning curve for me on whatever nuances appear.

 

[Newbomb Turk]

The rotating assembly is a MP 3.45 forged 8 bolt crank with the flat top MP forged pistons set at a positive deck height of .018. The MP con rods were shelved because they were in a OOTB condition. Which means they weight a hair more than the stockers, were in need of finishing to a lighter weight and balanced. While the rod could have been used as is, it was just more work for the machinist and that’s time and money I did t want to spend and to be honest, the machinist said he would rather not do. Even more so since I had some Eagle forged rods ready to go.

This rotating assembly is designed for a small main block, which I don’t have for the kits piston size of 4.03. I used a 360 block and main bearing spacers from Bill Richardson which allows the small main journal crank into the large journal 360.

Total cubic inches are 352.

The cylinder head for use will be varied for some dyno testing and experiments. Same with camshafts. The only thing I’ll let loose at this time is the following cylinder heads available for fun.

Stock 1.88 J, Promaxx CNC, Hughes Big Mouths, W2, W5.
I’ll be working on a set of ported J heads I’ll port myself later & I’m playing with the idea of just simply equipping another set of W5 with gear and running them without porting them.
Just to see what they do.

You’ll have to watch my YouTube channel for future actions, experimentations and engine builds.

No worries, I have only mentioned it in passing.

I also have a 340 that I had the KB domed (replacement) piston installed. My instructions to the machinist were to have the major area of the flat portion of the piston at zero deck which should give a stock height some positive position.

The Promaxx CNC’d heads are on top of that now along with a RPM AG, AFB 750, standard headers, 1.5 roller rockers and a XE285HL that I asked Comp to modify to a 108 LSA.

Both of these positive deck height list ones engines are not what I’m used to working with. Normally I used a zero deck flat top. So this is a learning curve for me on whatever nuances appear.

How much were those bearing spacers and did you have to line hone the block before you installed the spacers? I know you have to do it after you install them.

 

[Deltatech]

A 500Hp 440 is currently cheaper to build than a 400HP 318. I just finished another and the 440 was $2000 cheaper. Start with a 360 or 440 if you can.

 

[AJ/FormS]

I'm researching ways to improve both the torque and throttle response of a 318.

The best way to do both,
> is to assist the engine in processing air.
>This begins with a solid foundation, and don't let anyone tell you different, this means a having a decently high cranking compression number.
> it's ALL, I say ALL
about getting as much air into and thru the engine, as is possible, which includes keeping that air dense, on it's way into the chambers.
On a street engine, you have the unfortunate problem of making whatever monster you build, work within the confines of the rest of the combo. And, unfortunately, the engine has to be throttled some 95 or more percent of the time; which brings the difficulty of carburetion into play..

So then,
to optimize for street,
the first decision you have to make is; What fuel will you be using. If best fuel available is just 91, then that is your first handicap.
If that fuel is to rich for your blood, then that is your second handicap.
If then your DD project becomes a weekend warrior, that's a new handicap.
If the chassis will not accept decently sized tires, there's another handicap.
If the vehicle in question weigh over two tons, there's another.
If it is stuck with a low-stall convertor, and hiway gears, those might have to be replaced.
And if you are at altitude, that could kill the 318 altogether.

It's easy to get carried away with designing a hi-powered 318, only to find that your dream car will never run with it until everything behind it is upgraded, and the car still only does one thing right, and it's not what you had expected.
If you don't already have a car, I highly recommend to not start building a 318. If you all of a sudden can't find a relatively lightweight A-body in your budget, and end up with a 4000pound behemoth, then you may need a bigger engine.
Your guide for acceptable performance is 10 cubes per 100 pounds of ready to run chassis, you not in it. So then, at 4000 pounds, you will need a 400 cuber. Whereas the 318 is good at around 3200, and a 360 for 3600 pounds.
Operating outside these guidelines will be either disappointing or expensive.
So I mean, if you find a beautiful 71 Polara in your price range, she's gonna need a 360 or more. and trying to find a lightweight A in rebuildable condition, is as good as impossible but if you do, well then, mortgage the house.

Building the 318 from scratch to meet your goals is doable, if not cheep. Whereas fitting it into a winning combo, make take some ingenuity. It's just way easier with a bigger engine.
And no, I'm not knocking the 318. You can fit it into almost any combo with higher stall than stock convertor, and/or gearing, and the overdrive auto is a fabulous solution.
If you can commit to one of those, then the 318 becomes much more attractive.
If you want to discuss ideas away from the naysayers, you can PM me.

 

[rumblefish360]

How much were those bearing spacers and did you have to line hone the block before you installed the spacers? I know you have to do it after you install them.

Ahhhhhh, crud…. IIRC, $400 for the spacers. The block didn’t need a line hone. It was checked of course.

 

[Bewy]

More tq? Tq is cu in related. There is only so much tq you can get out of a 318. Best bang for the buck for more tq that you can feel.....is more cubes.

 

[rumblefish360]

The best way to do both,
> is to assist the engine in processing air.
>This begins with a solid foundation, and don't let anyone tell you different, this means a having a decently high cranking compression number.
> it's ALL, I say ALL
about getting as much air into and thru the engine, as is possible, which includes keeping that air dense, on it's way into the chambers.
On a street engine, you have the unfortunate problem of making whatever monster you build, work within the confines of the rest of the combo. And, unfortunately, the engine has to be throttled some 95 or more percent of the time; which brings the difficulty of carburetion into play..

So then,
to optimize for street,
the first decision you have to make is; What fuel will you be using. If best fuel available is just 91, then that is your first handicap.
If that fuel is to rich for your blood, then that is your second handicap.
If then your DD project becomes a weekend warrior, that's a new handicap.
If the chassis will not accept decently sized tires, there's another handicap.
If the vehicle in question weigh over two tons, there's another.
If it is stuck with a low-stall convertor, and hiway gears, those might have to be replaced.
And if you are at altitude, that could kill the 318 altogether.

It's easy to get carried away with designing a hi-powered 318, only to find that your dream car will never run with it until everything behind it is upgraded, and the car still only does one thing right, and it's not what you had expected.
If you don't already have a car, I highly recommend to not start building a 318. If you all of a sudden can't find a relatively lightweight A-body in your budget, and end up with a 4000pound behemoth, then you may need a bigger engine.
Your guide for acceptable performance is 10 cubes per 100 pounds of ready to run chassis, you not in it. So then, at 4000 pounds, you will need a 400 cuber. Whereas the 318 is good at around 3200, and a 360 for 3600 pounds.
Operating outside these guidelines will be either disappointing or expensive.
So I mean, if you find a beautiful 71 Polara in your price range, she's gonna need a 360 or more. and trying to find a lightweight A in rebuildable condition, is as good as impossible but if you do, well then, mortgage the house.

Building the 318 from scratch to meet your goals is doable, if not cheep. Whereas fitting it into a winning combo, make take some ingenuity. It's just way easier with a bigger engine.
And no, I'm not knocking the 318. You can fit it into almost any combo with higher stall than stock convertor, and/or gearing, and the overdrive auto is a fabulous solution.
If you can commit to one of those, then the 318 becomes much more attractive.
If you want to discuss ideas away from the naysayers, you can PM me.

More tq? Tq is cu in related. There is only so much tq you can get out of a 318. Best bang for the buck for more tq that you can feel.....is more cubes.

Double bingo. It’s all about the combo. While Bewy is correct, maximum torque production from the 318 is limited and improvements can only go so far. This leads to the question, how thick is your wallet?

Someone said earlier, the easier it is to maximize breathing in and out is the best way to start the journey. Camshaft selection is next. This is based on the rpm range your driving in and/or use most often. Coupled with the weight of the car, the gear ratio and tire size as well as the over all goal of the car.

don't over cam it, don't over carb it.

get some reasonable compression, decent heads, 1 5/8 dia full length headers (tri-y, etx, non fenderwell), dual plane, 600~750 cfm carb, factory electronic ignition.

“LIKE”

since you're setting the dial to "stun" and not "kill" anything from a "302" to a 360 2bbl head will be fine-- adjust compression as necessary.

Dislike, reason being, and IMO on;
The “302” head is because as cast, there terrible. Ported there very good.
The “360 - 2 barrel heads” are the same as 360 - 4 barrel heads.
Just incase you didn’t know but I think you do, but more so for those that are new to MoPars.

converter and gears are going to make more of a seat of the pants difference than an extra 50 tq or hp.

Also @Dan the man

Heck yea. Though Dan specifically asked about the engine, which I think is the starting point in his head. Your still right. One recent example of this was done in my Magnum where I have a 2000, 5.9 with just headers, coupled with a Edelbrocks 750 & RPM intake up top and a chrome box ignition. The rest is a 727 & 3.55’s on 245/60/15’s.

The stock gears were 3.23’s in the 9-1/4 rear end. When the pinion seal let loose on the Hwy destroying the pinion and everything else, I went a step up to 3.55’s. A minor improvement but I liked it. Later on, I added a mild 2500 stall converter and installed a new trans, both from TCI.

Just this small adjustment to a relatively mild engine changed its performance a lot in a positive & aggressive manor. The additional stall helps on the take off and the firm shifts of the transmission is a strong and quick shift that the stock trans was missing. Now it’s chirping the tires at the gear change if not a little little bit of tire spin.

I like it in the heavy late model B body, it’s gotta be really cool in a lighter A body.

Once Dan has his ride and upgrades his engine, a transmission package coupled with gears and sticky tires will sew it up well for him.

 

[junkyardhero]

Dislike, reason being, and IMO on;
The “302” head is because as cast, there terrible. Ported there very good.
The “360 - 2 barrel heads” are the same as 360 - 4 barrel heads.
Just incase you didn’t know but I think you do, but more so for those that are new to MoPars.

generalizations in the case of brevity and all that. your point is well taken on the 302 head, and i would *think* anybody would understand the need to port them (i would hope, at least). however, the compression bump from the closed chamber would be worth the hassle, i would think-- from a DIY/budget standpoint.

while i know that they're the same, most people pass them over for X's, J's or hunt out 4bbl units so i figured worth a mention, especially when that's what you'd be more likely to see kicking around out in the wild.

your point on gears and a converter changing the entire characteristics of the car and waking up a motor is well put. amazing what a little bit of change in that department can do.

 

[rumblefish360]

generalizations in the case of brevity and all that. your point is well taken on the 302 head, and i would *think* anybody would understand the need to port them (i would hope, at least). however, the compression bump from the closed chamber would be worth the hassle, i would think-- from a DIY/budget standpoint.

I never cc’d 318 heads but just go by what’s advertised. Not the greatest way to go about things.

while i know that they're the same, most people pass them over for X's, J's or hunt out 4bbl units so i figured worth a mention, especially when that's what you'd be more likely to see kicking around out in the wild.

Agreed there for sure. Even more so if you aren’t going to port the head. While the letter heads may be a better head to start with, in mild applications, the butt dyno is hard pressed to know the difference.

your point on gears and a converter changing the entire characteristics of the car and waking up a motor is well put. amazing what a little bit of change in that department can do.

Thanks & Amen!

 

[66fs]

I don't have a car at this time. I'm researching ways to improve both the torque and throttle response of a 318. I've always liked learning about ways to improve a engines performance. I've read that short duration cams are one way, but what about cylinder heads, what runner size, valve sizes to use? Compression ratio, open or closed chamber cylinder heads? Header tube size and exhaust pipe diameter. Ignition timing. I saw a couple of threads earlier on the 318 but I didn't want to hijack another person's thread. I'm working on being more open minded on things and not trying to come off as a expert on anything. I really hate that I missed out on the 1972 dart, but I'm looking steady and looking farther out. Thanks everybody.

First, you need a car. You should tailor some mods with a car in mind, like 66 down or 67 up. Any 318 will make a really nice street car. What do you want. All around, drive anywhere, pump gas, decent mpg? Think a 340 Duster? NO special parts needed. 318 short block, 360 heads, cast 340 or 360 intake, rebuilt TQ, AVS, AFB. 9:1 pistons, bore and hone with torque plates, stock crank, stock rods, ARP rod bolts, balance the works, add a windage tray, and a hp oil pump spring. Dual exhaust, manifols or headers. Call up a cam grinder and get a camshaft with honest answers to questions they will ask. Call 3 or 4 and go with the one you like best. Get valve springs that match the cam. 3.23 gears, good tires, brakes up to snuff, and a decent transmission. Go enjoy your car.

 

[Hysteric]

The “302” head is because as cast, there terrible. Ported there very good.

Run them you might be surprised. Mine ran remarkably well with just a 1.84 valve increase on a 360 cuber and I was stunned. The engine was still pulling strong at 6K.

Here ya go

One for the 318 lovers

 

[rumblefish360]

Run them you might be surprised. Mine ran remarkably well with just a 1.84 valve increase on a 360 cuber and I was stunned. The engine was still pulling strong at 6K.

Here ya go

One for the 318 lovers

With the 1.84 is a boost to the heads power potential over what it came stock with.

 

[Hysteric]

With the 1.84 is a boost to the heads power potential over what it came stock with.

True but still considered by many to be too anemic to feed a 360 at that rpm

 

[rumblefish360]

True but still considered by many to be too anemic to feed a 360 at that rpm

Considering you have moved the goal post from a as cast head into something modified, pitch this to the future owner of a performing 318. That would be member “Dan The Man.”

All things considered, once you can convince Dan to actually purchase a car, and then do this mod, contact me on this subject again so I can offer you congratulations.

Also have fun convincing others to use a iron 318 smog head.

 

[dirty white boy]

its a decent head for a max 300 hp driver! by time you put big valves in them and port them magnums become a better bang for the buck till thay crack! after paying machine work, and porting,... speedmasters become the better fire cracker! last thing any body wants is added machine work now days when the same money puts you in new aluminum territory! like i said,.got a set of 302s with 86,000 easy granny moses miles on them for sale cheap!

 

[dirty white boy]

another thing, find a porter that will do them 302s!! most dont want to see cast iron heads, wont touch them!! my brother got 20+ years of building porting sbm nascar heads and wont touch mine for love or money!! said hed only work on aluminum! same with most others with the skills....DWB

 

[273]

Most people aren't gonna port their heads and even if they did no guarantee their gonna get great results. So your basically talking stock or pay someone else to do it.

If looking for decent power 300-425 hp stock 273/318 heads aren't the way to go. Especially with mild cams and CR. I'm sure if you cranked up the cr and duration we'd be surprised the hp out stock 318 heads but most are gonna be lucky to break 300 hp. And if you got the ability to port a set of heads you probably don't need to be asking how to make 300-425 hp.

 

[273]

Plus equal work porting/valve/vj etc.. to 360/5.9 heads will give you probably at least 40 more cfm over 273/318 heads why give up 60+ hp, nevermind a set of aftermarket heads.
No one is saying 302 can't work, they just don't make much sense in most cases.


Imagine a basic zero decked 318-328 with a xe268h cam airgap and headers. Now picture it with everything from stock 302 to edelbrocks maybe even trick flows and the power differences.

 

[dirty white boy]

Plus equal work porting/valve/vj etc.. to 360/5.9 heads will give you probably at least 40 more cfm over 273/318 heads why give up 60+ hp, nevermind a set of aftermarket heads.
No one is saying 302 can't work, they just don't make much sense in most cases.


Imagine a basic zero decked 318-328 with a xe268h cam airgap and headers. Now picture it with everything from stock 302 to edelbrocks maybe even trick flows and the power differences.

afford the best head you can! why im porting my own magnums, best bang i can afford!! id love to go aluminum but ant got the bucks, same reason i ant stroking it, 2 grand to much!

 

[dirty white boy]

whats really sad dan the man cant find a mopar for less than 10g,..im trying to build a 200 dollar duster to run low 7s in the 1/8th for less than half that, and will probably have it running before he ever buys a car!