415HP from 318ci IS POSSABLE!!

-
You can build a 318 to make 450 HP and be perfectly streetable. How do you do it? FORCED INDUCTION. Or design some DOHC 4-valve-per-chamber heads for it. People forget that most of the engines we deal with here are cam-in-block 2-valve-per-chamber engines with wedge-type chambers that were designed in the 1950's and '60's. NOT the most efficient design out there but they can make a lot of power simply because they are big and very tough. People have to understand that these engines have a power threshold that once passed there is no way to get good gas mileage or be easy to drive around every day.
 
Fstforward said:
Back in the mid 70's, I hada 65 barracuda, 273 .060 over, built full race, professionally, dyno'd @ 422 hp, ran that little car to 12 flats on pump gas.

Tranny was 4 speed offa a 392 hemi car, rear was a ford 9" with 4.11's and "limited slip"(not my choice, bought it that way).

Car was a ***** to drive in traffic, plugs loading up fast, but was really fun when you pushed down on that pedal!!!!!!

Damn, I wish I had that car back now!!!!

Oh, and 3pmg city, 18 mpg on the highway, I drove it from Mississippi to
Pittsburgh in December of 1974 and lost the starter in Jackson Mississippi, and this was not a car you could start down a hill and catch it in gear to start it, even in third gear, the rear tires would lock from the compression.

FF
Click to expand...

Thats awesome! :cheers:

As always ramcharger has a good outlook on things.

An i FOUND IT!

HERE THE ARTICLE!
So i was 20 hp off, sue me !

But very impressive,hope this helps...

http://www.popularhotrodding.com/tech/0901phr_mopar_318_magnum_engine/index.html
 
So what is a good recipe for building a streetable 318, cam, heads, intake, induction, headers (size)..........This motor would have to make an easy 325 horse with at least 300-375 lbs of torque.....can this be done easily and not at the expense of high rpm operation. I would rather use the 318 I have than spend the change for finding a decent 360, as they are not very common around here........
 
don't get discouraged by all the negative 318 talk,it's still head and shoulders above the 360.When they dropped the 340 in favor of the 360 it was a cold day at mopar.With it's long stroke and short rod ratio all they created was a pig.Not to say you can't create smething more out of it but why?If you want a fast drag car there are much cheaper ways of going about it without ruining aclassic car.The 318 has almost as much potential as a 340 and easier to come by.With the right cam along with a good dual plane intake and the right gears and 904 tranny (not 727)it has less rotating mass,it will spank a 360.The 318 and 340 rev quicker and in a light A-body it's by far the best combo buck for buck.I run a 1995 magnum 318 with xe264 cam with a power-product intake with Edelbock 750 and otherwise stock 9.5 comp.ratio motor in my 66 valiant along with a turboaction 904 and get 20+ highway and will run 13's all day long.Maybe not the fastest but thats not why I built her,she brings back memories of my duster and cudas of the past and looks good to boot.So don't give up your thoughts about doing a 318,I think you'll be very pleased with what you end up with.
 
nemesis said:
Thats awesome! :cheers:

As always ramcharger has a good outlook on things.

Only because I've done more than just read magazines. I've made mistakes on engine builds and am just trying to help other people from making the same mistakes. By no means am I saying I'm perfect or know all.

An i FOUND IT!

HERE THE ARTICLE!
So i was 20 hp off, sue me !

But very impressive,hope this helps...

http://www.popularhotrodding.com/tech/0901phr_mopar_318_magnum_engine/index.html
Click to expand...

Very impressive. Custom crank, oiling system, chevy rods, super low tension rings, custom stroke, iron heads ported to flow best at over .600 lift, giant solid roller, custom valvetrain, custom 950 CFM Holley, custom cooling, etc. This is a one off engine that would cost someone who wasn't a machinist 15 to 20 grand.

This was built to win a contest on a dyno, period. It would never live on the street.
 
morleysrt said:
don't get discouraged by all the negative 318 talk,it's still head and shoulders above the 360.When they dropped the 340 in favor of the 360 it was a cold day at mopar.With it's long stroke and short rod ratio all they created was a pig.Not to say you can't create smething more out of it but why?If you want a fast drag car there are much cheaper ways of going about it without ruining aclassic car.The 318 has almost as much potential as a 340 and easier to come by.With the right cam along with a good dual plane intake and the right gears and 904 tranny (not 727)it has less rotating mass,it will spank a 360.The 318 and 340 rev quicker and in a light A-body it's by far the best combo buck for buck.I run a 1995 magnum 318 with xe264 cam with a power-product intake with Edelbock 750 and otherwise stock 9.5 comp.ratio motor in my 66 valiant along with a turboaction 904 and get 20+ highway and will run 13's all day long.Maybe not the fastest but thats not why I built her,she brings back memories of my duster and cudas of the past and looks good to boot.So don't give up your thoughts about doing a 318,I think you'll be very pleased with what you end up with.
Click to expand...

Yes, the 360 was a pig in stock form as was the B block 400, but this was only due to low compression from the factory, nothing else. The rod ratio is 1.85 on 318 vs 1.71 for a 360. You'd never notice it in any street application and is still better than a SB Chevy. Less rotatating mass? Sure, the smaller the engine, the less the rotating mass you'll have, hence the availibilty of lightweight pistons and rods. Just because a 318 has less rotating mass doesn't mean I wouldn't drop a stroker B Block in my Duster.

What you've done is a great, sane build for a 318 and I applaud you for using a common sense approach. The only thing I would've done different is use a roller cam since you have a roller block.
 
I had the cam already otherwise I would have opted for the roller.As far as rotating mass,I was refering to the 904 vs the 727.The sm blk mopar runs much quicker with the 904 behind it.And as far as the 360 being a pig,it was in the stock form I was refering to,although I still think the 318 magnum is the way to go dollar for dollar.Also,340's begining to become quite rare,The magnum 360 with the 318 magnum crank and bored .040 makes a killer package with the roller setup.Just a thought.
 
morleysrt said:
I had the cam already otherwise I would have opted for the roller.As far as rotating mass,I was refering to the 904 vs the 727.

You are 100% right in regards to the 904.

The sm blk mopar runs much quicker with the 904 behind it.And as far as the 360 being a pig,it was in the stock form I was refering to,although I still think the 318 magnum is the way to go dollar for dollar.Also,340's begining to quite rare,The magnum 360 with the 318 magnum crank and bored .040 makes a killer package with the roller setup.Just a thought.
Click to expand...

Does the Magnum 318 crank have the same main journal size as the Mag 360?
 
yes the magnum roller blocks share the same journal size but the 318 is internaly ballanced where as the 360 is not.Also if you want to run a carb the earlier LA motor accessories such as waterpump and timing cover w/fuel pump will bolt up,or you can leave it in stock roller form and run fuel injection .And you can adapt chev roller rockers to it if need be.One other thing,there is a s--t load of them around.
 
ramcharger said:
Very impressive. Custom crank, oiling system, chevy rods, super low tension rings, custom stroke, iron heads ported to flow best at over .600 lift, giant solid roller, custom valvetrain, custom 950 CFM Holley, custom cooling, etc. This is a one off engine that would cost someone who wasn't a machinist 15 to 20 grand.

This was built to win a contest on a dyno, period. It would never live on the street.
Click to expand...


I beg the differ, i rekon it could be driven on the street no sweat
at all an on pump fuel.
Like weve said before,what 1 person finds streetable
another might not.

15 grand? Dunno bout that, but yeh engine coatings an some
of the other stuff mentioned isnt cheap..
If it DID cost 15 grand,id go 426 hemi every time...
Never see them here in aus..
 
nemesis said:
I beg the differ, i rekon it could be driven on the street no sweat
at all an on pump fuel.

Pump fuel? Sure. But that's not where the problem lies.

Like weve said before,what 1 person finds streetable
another might not.

Absolutely, everyone has there idea of streetable. I said it wouldn't live on the street. They had a hell of a time getting those rings to seal on the dyno, not good. He also shrouded the cam tunnel, good for the strip, bad for street longevity with no oil splash on the mechanical roller lifters. The valve margins would also have to be in the neighborhood of 1/32 to get those heads to flow they way are. That engine would not live long on the street. Add in a yearly break down to check the mechanical rollers and spring pressures and it's not what I would reccomend to the original poster as a daily driver.

If you consider a 5000 rpm torque convertor, 950 HolleyHP and 4.88 gear ratio streetable, more power to ya. :-D

15 grand? Dunno bout that, but yeh engine coatings an some
of the other stuff mentioned isnt cheap..
If it DID cost 15 grand,id go 426 hemi every time...
Never see them here in aus..
Click to expand...

The machinist took 5 pounds off a 340 crank and got it balance. The mallory metal alone would cost 500 bucks. I'd say there was 4K+ into just the crank including turning down the rod journals, profiling and re-hardening. That Holley 950HP runs about $800 before any of the custom work was done. Custom Diamond pistons are over a grand, not including the machinists time to measure everything up. I see this build topping 5 digits easy.

Now here's a build that 470 HP at the crank by BJR Racing: http://www.forabodiesonly.com/mopar/showthread.php?t=28974

It could be done at less expense than the aforementioned build but if you PM'd BJR, I imagine that he wouldn't call this a daily street driver. :)
 
The 318 debate rages on.... I am building a 318 because I want the challenge-LOL. My experience with the 360 has been very positive, power and torque come relatively easy with that engine. But core 360's are starting to be hard to come by, and 318's are plentiful. If my "low buck" 318 can even make 375 horse at my altitude, I will be happy. And it will be all mopar save the cam and intake. I would love to have a 340, but there are no low buck 340's in my neck of the woods.
 
Here is the 318 combo that I am dropping in my dart soon. According to comp cams desk top dyno it should be good for 340 hp 384 tq.

Stock bottom end 73 318. Flat top pistons .060 in the hole. .026 head gaskets. 5.2 magnum heads with factory 1.6 rockers. Comp XE256H (256 intake-268 exhaust- lift .447-.455 110 [email protected]) Magnum dual plane intake. Holley 600 6619 carb. Hooker Comp 3" headers. Dual 3" exhaust thru flowmasters. Accel vacuum advance distributor. MSD 6AL box.

I think it is pretty impressive for a 318
 
ramcharger said:
The machinist took 5 pounds off a 340 crank and got it balance. The mallory metal alone would cost 500 bucks. I'd say there was 4K+ into just the crank including turning down the rod journals, profiling and re-hardening. That Holley 950HP runs about $800 before any of the custom work was done. Custom Diamond pistons are over a grand, not including the machinists time to measure everything up. I see this build topping 5 digits easy.

Now here's a build that 470 HP at the crank by BJR Racing: http://www.forabodiesonly.com/mopar/showthread.php?t=28974

It could be done at less expense than the aforementioned build but if you PM'd BJR, I imagine that he wouldn't call this a daily street driver. :)
Click to expand...

About the only thing that I would change is I would use the 85-89 318 pistons instead of the KB167's as the pistons would be in the hole about .030 or so and this would drop the compression ratio to a pump gas running engine and should yield a 10:5 compression engine or just over. The rest of the engine could be run on the street and the gearing and converter would be changed, along with the carb to a 3310 VS unit. The 112 centerline will make this engine very streetable, and have plenty of low end TQ. and HP. This engine would be good to 6,000 RPM's. This engine would make 219 HP and 384 FT. Lbs TQ @ 3,000 RPM's and 484 FT.Lbs peak @ 4,500 RPM's and 501 HP @ 6,000. So IMO I wouldn't go through all the rod work on the beams but would resize them, as the street wouldn't ever see the performance gain the light weight rod's achieve. But it does make them more durable.
 
BJR,

You are talking about the changes to your specific build to make it somewhat streetable, correct? Think you'd be able to run power brakes with the cam LSA change?
 
Ram the bjr build you mentioned runs on alchohl.....?
if so,well how is that streetable lol
 
nemesis said:
Ram the bjr build you mentioned runs on alchohl.....?
if so,well how is that streetable lol
Click to expand...

I didn't. Read closely: "It could be done at less expense than the aforementioned build but if you PM'd BJR, I imagine that he WOULDN'T call this a daily street driver."

I just said that it would be cheaper to build.
 
Scrap that then!
F*** running alchohl.

I like street cars to run on pump fuel.
The minute something needs some form of tinned race gas to
run i lose respect for it.

Race gas= for trailered race cars.
 
nemesis said:
Scrap that then!
F*** running alchohl.

I like street cars to run on pump fuel.
The minute something needs some form of tinned race gas to
run i lose respect for it.

Race gas= for trailered race cars.
Click to expand...

In post #39 he talks about how to lower the compression ratio to use pump gas as well as a few other changes to allow for some sembelance of street use.
 
ramcharger said:
In post #39 he talks about how to lower the compression ratio to use pump gas as well as a few other changes to allow for some sembelance of street use.
Click to expand...

Yeh i read it.
:cheers:

Go the 318's!

ITs the the lil engine that COULD :cheers:
 
ramcharger said:
BJR,

You are talking about the changes to your specific build to make it somewhat streetable, correct? Think you'd be able to run power brakes with the cam LSA change?
Click to expand...

Yes, your correct. You should be able to but it really depends on how well the engine is machined and how well it seals, as this has a direct effect on the engine vacuum. This engine in my car had 12-14" of vacuum. 12 on the rich side and 14 on the lean side. Also keep in mind that I used a single plane manifold not a dual plane manifold, this has a tendancy to drop vacuum some too. Also I set the timing at 30* and raising the timing up a few degrees will add more vacuum.

The worst case senerio would be to run a vacuum canister but I don't think that it would be needed.
 
I also ran this engine on 87 octane gas at the race track a few weeks back and it ran a 7.401 @ 96 mph without any signs of detenation on the plugs. I used a 660 center squirter carb that flows 987 cfm's with 84 jets front and rear. The engine didn't burn a half a qt. of fuel per run. So the engine is very effecient.
 
You must log in or register to reply here.
-

Back
Top