magnum build guidance.

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magnumHP

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Feb 21, 2017
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Ram Year
2000
Engine
318 magnum
hello all! im getting ready to build my 318 magnum. i have a basic knowledge for these engines, but would like some others opinions on where to go.

so a little about the build. its for a 2000 qcsb. its a 4x4 truck with a 5" lift. i use the truck for everything, playing in the mud, beatin up other cars and trucks on the street, hauling, towing, etc!

my goal is to be as close to 500hp to the wheels as possible! ive been looking at the following parts over at Hipotek.

hughes air gap intake

hyd roller cam 230/234 .506/.506 110lsa

eagle forged I beam connecting rods

Wiseco Pro Tru Piston SB Chrysler 318 Flat Top Pistons for 3.940 bore size

Magnum Indy 'X' Heads W/ 2.02"/1.620" Stainless Steel Mopar Performance Valves.

obviously going to need to figure out still what rocker arms i need, push rods, trans work etc.

my question is, can the stock crank handle the power? does my current list look like a good start/combination?

feedback is greatly appappreciated!
 

Marciel

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Ram Year
2006
Engine
5.7 hemi
That looks like a good start, your bottom end will be fine, your going to have to add forced induction on a 318 to come close to those numbers though. I would go on Hughes to find all your valve train parts but don't buy his air gap, get a Mopar m1 manifold. Next thing is the tranny , 46re I assume? That thing will need alot of help, I have an HD torque converter and stage 2 transgo shift kit in mine, helped it out.

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dapepper9

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2001
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5.9L V8
Screw that, only m1 you're going to be able to find is a 4bbl and those are setup for too much high rpm use. Go with the airgap, it can more than do your goal whilst retaining more tq. I can post up the guy's instagram but one guy with a 360, Eddie heads, big cam, 58mm tb, airgap and 10psi from a procharger made 525/640. Turbo and more boost is going to be the prob the easiest way to make that kind of power out of a 318 or you can also stroke and boost. Nitrous is always an option as well though that doesn't last forever.

500rwhp out of 318:
Airgap/m1
58mm tb or 4bbl tb
110-112 LSA cam, lift and duration at manufacturers recomendation
heavily ported EQ heads (much more cost effective vs eddies)
adjustable rocker arms and pushrods to match cam
ARP head studs
custom turbo headers and turbo and intercooler/piping (I don't have a good suggestion offhand, ON3 is a generally a go to for most though)
fuel system to match and full msd 6a box and coil

You're going to need to convert to 4bolt mains or the caps will walk. I can find a part number for that which you'll need.

And that's before addressing the trans
 

Marciel

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A turbo is a crappy idea for a 4wd in my opinion you don't want to wait for boost, and a plumbing night mare. With heads and a cam that small block is gonna make most of its power up high anyways. The hughes airgap isn't even a fuel injected aplication and needs an adaptor for your throttle body. All the mopar guys will tell you the m1 is better.

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dapepper9

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1. turbo lag is extremely dependent on turbo size and on a gas v8 even a pretty decently sized turbo spools quick
2. plumbing on a 4x4 is easier than a 2wd because you actually have room to work with and you can practically stand in these magnum engine bays. Flip the headers/manifolds around, run the crossover on the front.
3. heads cam power up high, though somewhat true, isn't a huge issue. Gears and stall converter will cover that as well as proper cam selection
4. umm...the airgap IS for fuel injection. It's an edelbrock airgap/crosswind machined with injector bungs and branded with Hughes. And being pretty involved in Mopar Magnum scene, I can tell you that m1 being better isn't necessarily true either. Most guys that will claim that are talking about the 2bbl m1 (like I run) or building up a 2wd Dakota or Jeep. 4000lbs max to the OP's 6000+ is a huge difference, a difference where the 2bbl and airgap REALLY shine over the 4bbl unless running a big boosted stroker. The tq loss from the 4bbl is simply too great for such a heavy vehicle.

I hate hughes as much as the next guy and if you go through my posts on here I don't hide it, however, I do have to give the intake it's due. 255cfm/runner is more than most guys will EVER need and especially in boost situations the difference in HP between the airgap and larger m1s shrinks while the airgap greatly surpasses it in tq. The 2bbl m1, if you can somehow find one, I'll always recommend over the airgap though. It performs virtually the same as the airgap on the lower side; just slightly less tq production though it's negligible in most situations. Under boost it performs again very similar to the airgap by creating high tq output but it also flows 15cfm/runner more giving it a higher peak power advantage.
 

Yeret

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Engine
5.9 Magnum
Forced induction is the only practical way that you're going to generate that kind of power in a 318 and retain any kind of driveability in a 4x4 second gen. I have no doubt that a 318 can pass the 500 mark naturally aspirated but the setup you would need would push the powerband so high in the RPM range that you'd never be able to practically use it unless you're okay with regearing the truck in such a way that you're highway cruise would be 3,000+ RPM. And if you want any kind of off-the-line acceleration with that setup/weight of truck, you'll need a LOT of stall.

OR, with a good boost setup and tune, you can generate 500+ and more and keep the powerband more or less the same as OEM. Me, I prefer natural aspiration but I'd never go as far as pushing for the 500 mark even with my 360. Most I'd do is stroke to 408 and aim for 400.

Whatever you decide to do, get ready to shell out some major green...
 
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magnumHP

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318 magnum
alright guys. so im seeing my expectations arent so reachable without boost. although ive managed to put away $6500 for my engine build, im currently waiting on paint job, lift, interior to be completed by a shop i took it to, so adding to my budget for a turbo, will be atleast a month or two until the truck (shell i guess since it has no engine) is complete.

but i will admit i was planning on adding a turbo this winter (winter of 2017/2018) when it sat in my garage. but im not completely knowledgeable on how to install a turbo yet. i have much research to do on the topic!

what numbers do you think im looking at with the above modifications listed? what numbers would i be looking at if i went the 390 stroker route?

also, what if i found a 360 engine instead? would that be better to build from? if so, that is another possibility.

thanks for all of the guidance! also, for those wondering about where i will go with my trans, honestly no idea. i will be pawning that job off to a co-worker who owns a transmition shop and leave him to take care of it and make sure it will hold up.
 

Max78

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Magnum 5.9
Edit: misread. . . lol

I find it easier to work with exhaust tubing than dealing with pulley issues and belt slip. The nice thing is a turbo will be much easier on all your drive line components and sized appropriately they can spool extremely quick.

Some things to know, retaining heat in the exhaust stream is more important than the design of your exhaust headers. Many people run cast iron headers and gain performance over thinner tube style exhaust manifolds. equal length headers are pretty useless now because the turbo is creating back pressure which kills the scavenging effect you get from them.

Open up that top ring gap!!! I only really know about the LT/LS series engine but for turbo applications it is recommended to open the top ring to .025" to .028" and the second ring to .025" to .030". This is to avoid the rings butting together and breaking a piston. Do more research on this.

Pre-turbo hot side, larger is not better and going too big will actually hurt performance. . . I use 2.25" exhaust tubing pre-turbo on my Camaro and while I have no dyno sheets it pulls clean and strong all the way to 7k rpm and stuck right along side a 600hp supercharged 05 GTO. You are looking to keep as much exhaust gas velocity as possible.

There are a ton of technical details about this but, generally the lower the compression the more boost you can safely run on pump gas without ****/water injection.
 

dudeman2009

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Arizona
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2001 1500 Sport with enough electrical modifications to make my brain hurt
Engine
Magnum 360
alright guys. so im seeing my expectations arent so reachable without boost. although ive managed to put away $6500 for my engine build, im currently waiting on paint job, lift, interior to be completed by a shop i took it to, so adding to my budget for a turbo, will be atleast a month or two until the truck (shell i guess since it has no engine) is complete.

but i will admit i was planning on adding a turbo this winter (winter of 2017/2018) when it sat in my garage. but im not completely knowledgeable on how to install a turbo yet. i have much research to do on the topic!

what numbers do you think im looking at with the above modifications listed? what numbers would i be looking at if i went the 390 stroker route?

also, what if i found a 360 engine instead? would that be better to build from? if so, that is another possibility.

thanks for all of the guidance! also, for those wondering about where i will go with my trans, honestly no idea. i will be pawning that job off to a co-worker who owns a transmition shop and leave him to take care of it and make sure it will hold up.

I don't have much experience at all building and tuning gas engines to make power, but many things are similar to diesel, which I have quite a bit of experience with. One of my old instructors at school was a diehard mopar guy who taught part time and custom build race engines. Its not hard to push 500hp from a 360, it just takes money, specifically, about $7k into the engine and trans. Getting a 318 there isn't unrealistic, but its harder as you have a slightly smaller bore and a bit smaller stroke, there isn't as much time per cylinder to make power in the 318 as in the 360. You'd need to make 12 more HP per liter in about 8% less stroke. Its very possible, it will just cost a bit more.

As far as ditching the 318 for a 360, if you don't mind spending an extra $400-800 to get a solid tight block, plus the slight bit extra for the 360 rebuild kit instead of the 318 kit. I say go for it. You'll have time to work on the 360 while still being able to drive your 318, the trans will bolt up no problem, you might as well have it re balanced after the build, so you'd follow the instructions of whoever is balancing it in regards to which flexplate to use. The 318s are internally balanced and use a neutrally balanced flexplate, the 360s are balanced by a weighted flexplate, i've seen some shops internally balance the 360s and just remove the weights from the flexplate.
 
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magnumHP

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318 magnum
anyone have any idea of horsepower numbers (to the wheels) my first post build would be making?
 
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magnumHP

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318 magnum
300-ish isnt bad. but i was looking to be more towards 400. id be happy for the year if i could be at about 400-425 to the wheels. any advice besides going forced induction? or would i be looking at unusable power if i went a little more aggressicve.

i am PROBABLY going to go with a turbo set up this coming winter. not 100% sure. still have to do research.
 

dapepper9

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Honestly 300 might even be pushing it with that setup. 360s are pretty much tapped out at 350whp if staying stock bottom end. You can build a bottom end that raises compression and is internally balanced but even doing all that 400 is not likely to be seen. To see that much power on an NA 318 you need either boost juice or displacement. 318s stroke out very well to 390s and make great power though not quite the same as 408s. Juice is a cheaper, often easier power adder
 
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