Mild Torque 318 suggestions wide open!

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2nup350

2nup350

the four doors are mandatory
Joined
Jan 6, 2013
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Location
Cataula , GA
I'm embarking on a sl6 to 318 swap. (automatic 904)
My wife says this car MUST be quiet -no headers. It must idle nice. It must have AC. It must not overheat. It must be fine with 70 mph. That said, I can spend some cash on this build no problem but don't want a fiddly exotic tuning nightmare. I think I'll shoot for 250 HP and as much torque as possible to get it off the line with my 276 gearset.
I'm gong to rebuild the 318. plan on bumping the compression up with pistons
Heads? 360 heads and intake- stock
5-650 vac secondary carb to retain a bit of mileage.
slant torque converter might be a good idea?
Bast option on exhaust? like a high flow cast iron manifold.
what cam to use? power just off idle-retain torque- sounds like an 80's truck cam but cam choices are infinite and I'm not "in the know" about them.
what kind of head mods would be most effective? I thought just a bowl polish and knock back the heart tip? Full porting would just slow the charge and cost torque?
Going to an aluminum radiator with dual electric fans-Griffin makes the best ones I've seen around.
Of course I have electronic ignition and such. I just need to talk to my engine guy soon and bat around ideas
Other worthwhile mods? Am I off base for my goals?
EDIT -NO Magnum Swap. I've got a 318, it's good, it fits, unless someone wants to trade?
 
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Sounds like low end torq is your greatest concern, so the easiest and cheapest way to dump a bunch of low end grunt in your car is get a 360.

If you are moving forward with the 318.....
  • TTI head pipes (2.5"), with 2.5 in duals out the back. Make sure your exhaust manifolds are at least 1 7/8", but bigger is availible
  • 302 heads will help, because you'll need the compression for low end grunt
  • Weiand Action plus intake is a good choice
  • Cam will open a huge debate..... but no bigger than a stock 340 cam.
 
And so it begins. I have the same needs. I have chosen a Edelbrock LD4B intake and a 600 Edelbrock. I also have a 1850 Holley. Exhaust works with 340 manifolds (which I haven't found yet) and a 2 1/4" dual system.,TTI or the like. Electronic Ign. of course with a advance tuned distributor. Cam I am up in arms about right now. Too many choices.
 
My advise is to forget rebuilding a LA 318....go to the junkyard, buy a magnum 5.2 (318) for about 350 bucks, throw a car oil pan on it and a conversion intake..DONE. better heads, better sealing, roller cam, ect ect ect.
 
My 318 has;
Lunati 10200701 cam About $210
Edelbrock performer intake 2176 Free, it was in the trunk when I bought the car
Summit M2008 600 cfm carb $about $290
Cloyes double roller timing chain About $50
No timing chain tensioner
Harmonic damper About $80 Make sure when you get one, it has the degrees very visible, like a black damper with white markings. Also, make sure you get the right one for your year 318 and timing marks on the cover.
stock 1968 675 heads
stock exhaust manifolds
stock single exhaust
HAD a 7 1/4 2.76 which died last week after those upgrades were in the car for only a year.

I cannot recommend that carb. It has icing problems when the temps are between 40 and 60 *F and high humidity.

I agree with post #4. Check out this site, lots of useful info.

Magnumlogotest.jpg
 
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Think about running an overdrive transmission.
Stepping 'down' to 3.23/3.55 gears will make the car feel snappier during acceleration while still being able to cruise at 70-80mph at ease in OD.
Spend time working the ignition curve. Quite some torque can be found down low.
A standard 3-core radiator with fan-shroud will have no problems cooling that 318. No need to 'blow' money on aluminium radiators and electric fans, although the fans might free up some power from the engine.
 
People somehow got the idea that strangling your engine gives you torque and adding free flowing parts gives you hp.

Hp and torque really ain't 2 different things.
Hp is just the sum of your engine torque and rpm abilities.

Unfortunately it's hard to increase torque of a N/A engine. Stock engine produce 1:1-1.1:1 lbs-ft per cid, a mild engine might get .5 more or so but without good flowing headers, heads, carb, intake etc.. it's hard to get more, even well built engine will struggle to get more than 1.35:1 lbs-ft per cid.

As you can see torque (low rpm hp) is tied heavily to engine size.

To me the trick is on a low performance engine (under 300hp) or any street engine is how far can you stretch the powerband without moving it off or too far from idle.
Obviously increasing the need for stall and gears if moved too high.

But really no needed to over think your build.
Stock 318 heads can get you 300 hp no problem. Any idle-5500 intake with a 650 ish carb. No need expensive manifolds 340 Will add 5hp at most so any 360/5.9 will do even 318 will only cost less than 5 hp.

So your engine build really just comes down to cam an cr choice. CR you'll probably want 8.8-9 to one. So that leaves just cam which you'll want a stock 340 ish cam or a modern design around 250-260. Especially one designed with manifolds in mind.

Now heads stock will more than do but you'll leave power one the table or make the same with a little less cam. Could doing a little porting on the 318 heads or upgrade to 360 or magnum heads.

For this low level build I'd start with magnum 5.9 or even the 5.2. They both make around 300 hp gross and almost you goal net.
So all you need then is to rebuild to stock and maybe a cam regrind to add a bit more power. If you could keep the beer barrel efi it actually increase the low end quite a bit and can tell you from experience (5.9 jeep) has lots of bottom end.
 
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I agree with the low nines for a static CR and a mild cam for an engine that will have decent low end torque and not be persnickety on tuning or running. To do this with the 360 heads, then you need to have pistons at zero deck (or close) height and a .028" thick 1121G head gasket. Likely pistons would be the KB167's and mill the heads about .015" to end up just above 9:1 on Static CR wiht an LA block.

Then, with a 260 advertised duration cam, with ICL at 106, you will be at around 7.5-7.6 dynamic CR and that will be pretty good but not aggressive. I would stick with a 112 (even 114) LSA for economy, vacuum, and smooth idle, and use a mild cam ramp to make it easy on the valvetrain. 1.6 rockers would be nice to get more lift and flow to extend the upper RPM band a bit.

Ditch the /6 TC, it will want to spin up on you with the added torque. Besides, why put an old TC behind a new engine?
 
My son's 73 Dart is what you are looking for. Stock untouched 1973 318, Mopar Performance small hydraulic cam, Cloyes double roller timing chain, 1967 273 Commando intake and AFB. 1973 340 exhaust manifolds, 2 in duals and turbo mufflers all the way back, 727 automatic with 340 torque converter, 7 1/4 Sure Grip 2.76 gears, 15 x 6.5 original Rallye's with Michelin tires. On a trip it gets a little over 20 mpg with regular gas and cruises all day at 75 mph. Any cam from 260 duration to a stock 340 cam will work nice. 318 marine engines were rated around 225 hp with small heads and valves, and cam. The other alternative would be to buy new pistons, use 340/360 heads and intake, and basically build a 340. Should be over 300 hp easy.
 
Whatever you do, have at least a 3.23 rear gear when ya do it.
Going with stock replace style rebuild...252 duration cam, performer intake, 600 eddy with 2 steps richer on the primary rods, 35 total timing, also take the heavy spring out the distributor and only run the weak one, that'll give ya about 18 initial till you goose it.
 
Most people get an X for not helping the fella out with the soul reason of he said "No Magnum swaps!"

He wants to use what he has. Which seems like a big problem for most posters in this thread except the thread starter and a couple of other well informed posters that can actually read AND understand what's written!

Good job fellas!
 
rumblefish360 said:
Most people gedon't a Xnfor not helping the fella out with the soul reason of he said "No Magnum swaps!"

He wants to use what he has. Which seems like a big problem for most posters in this thread except the thread starter and a couple of other well informed posters that can actually read AND understand what's written!

Good job fellas!
Click to expand...
Somebody in a bad mood?..... LOL C'mon Rob, there is plenty of stuff offered, even in my post. Just because "360" or "magnum" is mentioned doesn't mean all that is written is waste.... Besides, the OP "edited" his post and added "no magnum swap", wasn't there before. And neither was "I already have the 318" Better day tomorrow? :D
 
LMAO ... Thphhh

Help the man with the 318 LA!

LMAO!

Help him build what he has instead of collecting MORE parts no one else wants!

All we need now is stroked340 !!!!
 
rumblefish360 said:
LMAO ... Thphhh

Help the man with the 318 LA!

LMAO!

Help him build what he has instead of collecting MORE parts no one else wants!

All we need now is stroked340 !!!!
Click to expand...
Correct, he'll say 360 for sure :D
Problem is, OP went and edited his post.... He got responses according to his original post.
 
He added no magnum swaps to his OP after people suggested it.

The OP doesn't have to anything he don't want, the info is there now he can pick and choose want he wants.
 
273 said:
He added no magnum swaps to his OP after people suggested it.

The OP doesn't have to anything he don't want, the info is there now he can pick and choose want he wants.
Click to expand...
Besides that, the OP made it sounds like "spending cash isn't a problem", but a keeping it quiet and highway geared with lots of low end is key. So, he made it very easy to offer a "360" or "Magnum" to help him achieve his goals. Now he'll only consider those offers if "somebody wants to trade"...... LOL. If he has money for Pistons, Heads, cam, and everything else, the 360 and magnum suggestions were in line, if you ask me....
Good luck to the OP :D
 
comments in the quote
2nup350 said:
I'm embarking on a sl6 to 318 swap. (automatic 904)
My wife says this car MUST be quiet -no headers. It must idle nice. It must have AC. It must not overheat. It must be fine with 70 mph. That said, I can spend some cash on this build no problem but don't want a fiddly exotic tuning nightmare. I think I'll shoot for 250 HP and as much torque as possible to get it off the line with my 276 gearset.
To hit all these targets you need a 360
I'm gong to rebuild the 318. plan on bumping the compression up with pistons
Heads? 360 heads and intake- stock
5-650 vac secondary carb to retain a bit of mileage.
slant torque converter might be a good idea?
Bast option on exhaust? like a high flow cast iron manifold.
what cam to use? power just off idle-retain torque- sounds like an 80's truck cam but cam choices are infinite and I'm not "in the know" about them.
what kind of head mods would be most effective? I thought just a bowl polish and knock back the heart tip? Full porting would just slow the charge and cost torque?
Going to an aluminum radiator with dual electric fans-Griffin makes the best ones I've seen around. What's wrong with a mechanical set-up?
Of course I have electronic ignition and such. I just need to talk to my engine guy soon and bat around ideas
Other worthwhile mods? Am I off base for my goals? 360, hi-flow exhaust,4bbl, no cam, and done.
EDIT -NO Magnum Swap. I've got a 318, it's good, it fits, unless someone wants to trade?
Click to expand...

So you want to keep the teener, kindof shooting yourself in the foot then, but here's my 2 cents
Static compression ratio of 9.8:1.
Effective stroke is 2.74 inches.
Your dynamic compression ratio is 8.27:1 .
Your dynamic cranking pressure is 166.91 PSI.
V/P (Volume to Pressure Index) is 134
This is about the best compromise your gonna get on pump gas
The cam I used was a 252/260/114 in at 110. It has 32 degrees of overlap so will run fine with logs. I won't make a lotta power, but also won't suck a lotta gas. The VP of 134 is not all that bad.

Here's the same specs and cam in a 360
Static compression ratio of 9.8:1.
Effective stroke is 2.97 inches.
Your dynamic compression ratio is 8.30:1 .
Your dynamic cranking pressure is 167.70 PSI.
V/P (Volume to Pressure Index) is 153

Notice the VP is 153/134=14% higher.
The 360 will feel that same 14% more powerful in the lower rpms. Of course it is also 13.2% bigger, so it will just feel more powerful all thru the rev range.
The beauty of the 360 is that you can downsize the cam if you wanted to make better fuel mileage.
Or you could upsize it a lot, before the VP falls to the same 134.
Heres an example with a 272/280/110 cam, in at 106, still with the 360
Static compression ratio of 10:1.
Effective stroke is 2.84 inches.
Your dynamic compression ratio is 8.14:1 .
Your dynamic cranking pressure is 163.52 PSI.
V/P (Volume to Pressure Index) is 143
Notice the VP has fallen to just 143
Yet the cam is a very generous size that really wants headers. Again this is about the best compromise for a warmed up 360 still running pump gas and iron heads.So now the bottom end is feeling like 143/134=6.7% stronger than the optimized 318, yet making a huge buncha more horsepower than the 318. My guess is nearly a hundred more ponies.
Course you don't have to install this big a cam; your 360 can be optimized for almost any size cam. I just used a 272 for illustrative purposes.

Here's a 360 optimized for a 240/248/114 cam (teener cam)
Static compression ratio of 9.3:1.
Effective stroke is 3.10 inches.
Your dynamic compression ratio is 8.19:1 .
Your dynamic cranking pressure is 164.83 PSI.
V/P (Volume to Pressure Index) is 157

This will be a tire frier. Of course the cam is done around 4500, kindof perfect for those 2.76s; 1st is good to 50, and second to 85, and tops out at 4500=125. No need for headers, just duals.

Oh sorry, I forgot; the teener is staying.
Well in that case your best course of action is to get rid of 400 pounds.In my case, I drive alone.That solves a lotta problems for me. LOL

Here's an interesting comparo; a 440 with a 272 cam
Static compression ratio of 9.3:1.
Effective stroke is 3.10 inches.
Your dynamic compression ratio is 8.19:1 .
Your dynamic cranking pressure is 164.83 PSI.
V/P (Volume to Pressure Index) is 157
Notice the 157VP? Tire frier




 
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2nup350 said:
I'm embarking on a sl6 to 318 swap. (automatic 904)
My wife says this car MUST be quiet -no headers. It must idle nice. It must have AC. It must not overheat. It must be fine with 70 mph. That said, I can spend some cash on this build no problem but don't want a fiddly exotic tuning nightmare. I think I'll shoot for 250 HP and as much torque as possible to get it off the line with my 276 gearset.
I'm gong to rebuild the 318. plan on bumping the compression up with pistons
Heads? 360 heads and intake- stock
5-650 vac secondary carb to retain a bit of mileage.
slant torque converter might be a good idea?
Bast option on exhaust? like a high flow cast iron manifold.
what cam to use? power just off idle-retain torque- sounds like an 80's truck cam but cam choices are infinite and I'm not "in the know" about them.
what kind of head mods would be most effective? I thought just a bowl polish and knock back the heart tip? Full porting would just slow the charge and cost torque?
Going to an aluminum radiator with dual electric fans-Griffin makes the best ones I've seen around.
Of course I have electronic ignition and such. I just need to talk to my engine guy soon and bat around ideas
Click to expand...
For what you are wanting a stock type rebuild with your ideas would be fine. But everyone always ends up wanting more...
 
I have a weird thing about throwing out good parts. Call it a tic. I also have a thing about factory looking engines, I hate alloy intakes and chrome air cleaners. I'm also irritated by people who post just to sneer at me.
YES I said no magnums. They might be plentiful in junkyard near you but not here. and it means going out and getting ANOTHER engine (with cracked heads) and taking that to the machine shop to be checked. I'd trade if someone wanted my checked out block/heads in partial trade for their checked out Magnum stuff but I'm not going to abandon a good motor for no reason.
YES I am going to be happy with 250. My wife would be happy with dead stock. I'm going to push it a little but I know her limits- the first time it overheats in traffic or develops a highway drone she is going to fume.
I don't see anyone doing this kind of rebuild anywhere- it's always "gimme the highest power I can get out of this thing" I've got a pretty large budget but anything I can save will go to a new rearend, if I can bundle that in at the same time I'd be saving myself a headache. Just looking for advice, not judgment on my car/sanity/wife.
Thanks to you all.
 
In my opinion a stock 340 cam would be nice for that build. I had a 70 Charger with a 318 that has a 340 cam, thermoquad, dual exhaust and 2.76 gears.. It wasn't a race car but it pushed the Charger pretty well and the best part was getting 19 mpg on the highway.
Have fun and post pics.
 
rumblefish360 said:
Most people get an X for not helping the fella out with the soul reason of he said "No Magnum swaps!"

He wants to use what he has. Which seems like a big problem for most posters in this thread except the thread starter and a couple of other well informed posters that can actually read AND understand what's written!

Good job fellas!
Click to expand...
His original UNEDITED post said he was looking for opinions, and that's what he got...no need to be condescending after the fact...
 
rumblefish360 said:
LMAO ... Thphhh

Help the man with the 318 LA!

LMAO!

Help him build what he has instead of collecting MORE parts no one else wants!

All we need now is stroked340 !!!!
Click to expand...
I noticed all YOU did is come in this thread to "disagree" with people who ARE offering opinions....yet, you offer no valuable input on the subject yourself? Smh
 
For your wife, it sounds like this will be easy and the idea of not going too high on CR or cam or HP sounds spot on the money. I'll pull back my suggestion on the 1.6 rockers... it won't do a thing for her.... it's just for you LOL

Find a good 600 cfm vacuum secondary carb... the old List 6619 Holley's did a great job and had good economy, but it may be hard to find one in good shape. And if you want a stock type intake, then you may be stuck with a spreadbore type anyway.
 
replicaracer43 said:
I noticed all YOU did is come in this thread to "disagree" with people who ARE offering opinions....yet, you offer no valuable input on the subject yourself? Smh
Click to expand...
Yeah, let's stop talking about that. I really don't want to let this devolve into a fight. Just ignore what you don't like, I'm practicing that myself.
 
According to the op's first post, he should just freshen up the 318 with a basic stock type cam, add a 4 barrel and intake (something you can hang a/c on depending on what system he uses) and do some homework on a low drone exhaust. It didn't sound like he is poking for maximum performance. If so yhat will be a trade off of most of the items on his wifes list.
 
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