5.9 Magnum Torque motor build?

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Its about the same work as a rebuild for a few bucks less. Why work so hard fluffing up old worn out stuff when you can rebuild it. And maybe even give it the 6 million dollar man treatment, build it bigger, better, stronger, faster.... LOL

While ultimately it is your call and wallet, I really think the 5.9 is the best bang for the buck. Heck, for what I wrote above, add about $350 for a new roller cam better suited for towing and really leap ahead a winner.

Still want to spend big on boosting a half dead horse? Try it with a low mileage Magnum and spend another Benjamin on comtetic gaskets to lower the ratio 1 pt.

I don’t know how cheap you think you can effectively boost an engine but so far your acting like a cheap SOB or a broke one. (I’ll assume the latter.....) Boosting ain’t cheap, at least done right!
 
rumblefish360 said:
Its about the same work as a rebuild for a few bucks less. Why work so hard fluffing up old worn out stuff when you can rebuild it. And maybe even give it the 6 million dollar man treatment, build it bigger, better, stronger, faster.... LOL

While ultimately it is your call and wallet, I really think the 5.9 is the best bang for the buck. Heck, for what I wrote above, add about $350 for a new roller cam better suited for towing and really leap ahead a winner.

Still want to spend big on boosting a half dead horse? Try it with a low mileage Magnum and spend another Benjamin on comtetic gaskets to lower the ratio 1 pt.

I don’t know how cheap you think you can effectively boost an engine but so far your acting like a cheap SOB or a broke one. (I’ll assume the latter.....) Boosting ain’t cheap, at least done right!
Click to expand...

Haha I'll go with both of those assumptions on me. True, I'm just wanting to make sure I get all my options out of the way before I decide to go with something, I truly am very cheap so wanting to make sure I'm getting the most bang for my buck I can get while attempting every DIY possible lol. I heard the stock cam is already good, how much would a roller cam effect?
 
A Magnum engine is already a roller cam so a new cam brings in to many complex calculations to give a answer never mind an accurate one based on assumptions. There are just to many variables.

The best way you can partially predict power is through a simple desk top dyno program and start entering cam specs. The program is good and best used as a learning tool. This way you can see how various camshafts can react and dish out the power.
 
Having raced and upgraded a turbo car, I think you are off on a the wrong track with that for your low rpm TORQUE application. Having the lower 8:1 stock 318 compression ratio is just the start. For low RPM torque, getting the turbo to spool up at low RPM's is a very different matter. Using small turbo, having the impeller customized for quick spool-up and optimizing the cam are what you have to do... and sometime you have to tweak the engine compression ratio too. That's all on top of fabbing the exhaust, proper fuel pressure regulation, proper oil drain back system from the turbo bearings, and such... and it is all harder/messier with carbs vs FI.

This MIGHT have been solved...I have not looked. But most turbo work is geared towards higher HP and ignores the lower RPM torque.... so not suitable for how you want to use. And it is gonna cost you a whole lot more than you think in terms of money and effort.
 
As with the stroker a turbo is way over budget even for a u-fabber tailpipe build
getting low end torque with a turbo requires a special turbo or we did it with a pair with all the exhaust going in to one then as it spooled up used a cast stainless diverter to bleed into turbo two could get boos just winging the throttle!
no way would I use a retrofit hr on a 318 when the later blocks and later LA 360 blocks had the provisions built in
as does the Magnum- and the Magnum stock truck cam is perfectly ok for your use
without porting the heads you don't half an inch lift anyway- the 260 HRcam spec i mentioned was out of line- you could do it but you shouldn't (and it's too big for stock compression for down low grunt)
 
nm9stheham said:
Comp Cams has one.. the trick to getting any usable results is knowing what info and parameters to put into it.
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So the reason I had thought that was because of the turbo diesels, the turbo Cummins makes tons of power real low, @3,000. That might just be a diesel thing, IDK.
 
Wyrmrider said:
As with the stroker a turbo is way over budget even for a u-fabber tailpipe build
getting low end torque with a turbo requires a special turbo or we did it with a pair with all the exhaust going in to one then as it spooled up used a cast stainless diverter to bleed into turbo two could get boos just winging the throttle!
no way would I use a retrofit hr on a 318 when the later blocks and later LA 360 blocks had the provisions built in
as does the Magnum- and the Magnum stock truck cam is perfectly ok for your use
without porting the heads you don't half an inch lift anyway- the 260 HRcam spec i mentioned was out of line- you could do it but you shouldn't (and it's too big for stock compression for down low grunt)
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See I'm real new to all of this so whenn it comes to a project IDK what price range to expect. Do you suggest leaving the cam alone then on the mag?
 
Absolutely till you drive it and see if you can give up any grunt torque (a more duration cam)
Theoretically you could go to a cam with the same seat duration with more lift and more area under the lift curve giving a "deep breathing" effect
and /or high lift rockers (either would merit new springs and most likely machine work on the heads for keeper clearance- I know some grind their keepers...)
but neither would be cost effective
ditto with stock exhaust vs headers
at this point IDK if block hugger headers would fit on both sides- depending on the steering box etc so U have to get it in and eyball
to really help the low end you are looking at long tube headers- anyone make them for your truck? IDK maybe with a 2 1/2 collector
Tri Y would be better than block huggers- but still- for now- save your money There is a program calld Pipe Max which I would use B4 looking at headers
you need to find those who have built in the same rpm range U are shooting for and not chase more rpm= more absolute top end horsepower then have to regear and all that
My old Dakota has 3:54 gears RV converter and I tow with it
most any cam change hurts the starting up a hill with 4 horses or pulling the boat out of the lake grunt
1.7 roller rockers would give some gain but when I add up going to an adjustable valve train, springs and pushrods it takes all the fun out of spending money
maybe when I have to do a major rebuild- but then I'd go stroker
 
Slightly disagree

First, live with the cam in there for now.
Second, a cam change, a very minor one, can still be a bigger cam and work from idle or slightly off idle and not effect any drivability or leave a gap in low rpm power.

Third
Look for long tube headers. Skip pipe max and building your own headers. It’s a crazy overkill suggestion for answering the pipe max equation.
 
real close rumble
agree with leaving it alone till he gets a baseline - don't jump till you know which way and how high
The one of the other 318 HR's is slightly bigger than the 360 and should be a freebe from someone who has done a cam change
I do know that the RT cam or the Sausage regrind would cost him low end and they are not that much biggger- not worth it IMHO but let's see the baseline
Was not suggesting he build his own but figure out what to look for I'm thinking of 1 5/8 40 + inches long with a 2 1/2 collector but no idea if would be available for his chassis
BTW
here's a PM I got from over at FBBO

Hi Wyrmrider!

The motor's been dyno-tuned. Here's the dyno chart. I'm pretty happy with the results. 417 peak TQ at 3700 RPM. That's pretty good for a motor with a fairly stock idle, good vacuum, and assuming longevity. What surprised me was the extent of the power band: 90% of peak TQ from the bottom of the chart (2800) to 5100. 363 HP at 5000. 90% of peak HP from 4200 to the top of the chart (5200). The HP peak had a bit of a nice mini-band, too. I bet the thing would have had 350 through 5500 or so. The tires will not be happy about this. By the way, my name is Maurizio.
 
I couldn’t agree more after reading that.
IDK about header tube length though.
Never had a old truck to put headers on. I never needed a truck until I got the house.
(El-Camino’s don’t count!)
 
MoparTrucker said:
So the reason I had thought that was because of the turbo diesels, the turbo Cummins makes tons of power real low, @3,000. That might just be a diesel thing, IDK.
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It is just a diesel thing unfortunately. The very way they work makes them much better at making torque at low speeds. One way to think of it is a diesel has "slow" combustion that pushes the piston all the way down through its stroke where a gas engine has fast combustion that gives the piston a quick hard push at the top. It's the main reason why you don't see many diesels, even small ones (unless they're indirect injection which is inefficient and no one does anymore except Mercedes) that can rev past 5000 RPM (and that's even pushing it); there just isn't enough time for the diesel fuel to be injected into the cylinder AND fully burn when the pistons are moving that fast. A Dodge Cummins has a redline around 3000 RPM, I think they make peak torque down around 1800 RPM?
 
MoparTrucker said:
So the reason I had thought that was because of the turbo diesels, the turbo Cummins makes tons of power real low, @3,000. That might just be a diesel thing, IDK.
Click to expand...
Long stroke, long rod, cams totally different.... allowing the combustion process to complete, and for helping spool up the turbo at lower RPM's (it is still a rather slow spool up time) and totally sacrificing upper RPM breathing... which does not exist anyway in the tiny intake manifolds for those engines. The size is to get the boost levels waaay up, which the diesel can stand due to the combustion process being so different (as mentioned). Apples and oranges....

To make a turbo work well at low RPM's for a gas engine like these, you typically put in a smallish cam with wide LSA and small overlap, push the CR up a bit, put on a SMALL turbo, and tweak the impeller blades. Those things are what help the turbo spool up better at lower RPM's.
 
Wyrmrider said:
Hi Wyrmrider!

The motor's been dyno-tuned. Here's the dyno chart. I'm pretty happy with the results. 417 peak TQ at 3700 RPM. That's pretty good for a motor with a fairly stock idle, good vacuum, and assuming longevity. What surprised me was the extent of the power band: 90% of peak TQ from the bottom of the chart (2800) to 5100. 363 HP at 5000. 90% of peak HP from 4200 to the top of the chart (5200). The HP peak had a bit of a nice mini-band, too. I bet the thing would have had 350 through 5500 or so. The tires will not be happy about this. By the way, my name is Maurizio.
Click to expand...
And I bet the torque extends well below the bottom dyno RPM of 2800 based on the VE numbers holding steady down to 2800...

FWIW, welding on a collector extension to get to 18-20" long collector will improve low-mid range torque too. Easy to get that; any muffler shop can do it.
 
NM that dyno was for a AMC 343 stroked to around 360 (4.090 bore x 390 steel crank stroke if I remember correctly
I do not remember if he has the older square port heads (which did not flow well) or the later "dog leg" which do (better than stock chevy and mopar)
That curve is similar to what I found for my 440 Motorhome Motor (ported 915 closed chamber heads with stock Motor home valves with the Inconel exhaust (left some HP on the table) true 9:1 compression with .030 quench. I've also used this grind in 360 LA
It does pull without bucking down at stall (with low stall RV converter) and revs to 6K but with that torque curve you do not have to rev "past the HP curve" to still have hp after a shift- it really does not care much- but when you do rev to 6000 you drop down to around 4000 where, as you can see, you are still pulling strong
hate to loose momentum with the motorhome on a hill
The collector length is frequently overlooked and most are too big
 
NM- update to the above
was a AMC 360 stroke crank in .030 0ver 343 block giving the same as a .030 overAMC 360- 4.110 x 3.44
not a 390 crank- sorry- brain fade
some info from my notes

This AMC motor revs fast - and with the lightened Ferrea LS1 valve-train I'm using (about 40% lighter than stock AMC), it'll rev quicker than a French ***** and I don't want to be completely gassed by 6K.
My car's 3,300 lbs with an automatic transmission (with a nice street torque converter workup, about 1700 stall) (Most likely a Borg Warner Cruze O matic trans not toqueflyte) and 3.15 gears. (Classic AMC 67 Marlin --similar styling to the fastback Charger )
AMCs use a 1.6 rocker ratio, but I'm using 1.7 Scorpion rockers, so the Intake valve lift will be .521 (stock AMC 343 and 390 was .425).
(Intake is 256@.006 lift is .451 w 1.5- .491 w 1.6 .521 w1/7)
Mike (Jones) said it'll have tons of torque and build peak HP about 5100 RPM. He went with 264 @.006 .208 @.050 on the exhaust; The final exhaust lift is .508.
(164 @.006 208 duration @.050 with .478 on 1.6 rockers (.508 on 1.7 like mine)
He said the peak HP should span to about 5300 RPM (dyno chart shows flat HP from higher 4000s to 5200 where the pull ends)

My 343 is being stroked to 365 with custom pistons to lower the compression from 10.2 to 9.2 (ended up closer to 9.3) to run 91 octane, go from 0.080 in the hole to be at the deck, and has Molnar rods.
The 343 heads have a sweet street port; they flow about 260 intake and 170 exhaust.
( he could have had this stock with the later heads but he kept the "matching numbers heads and block)
The intake is a modified big-runner AMC 390 intake where I turned the four holes into a split plenum and lowered the divider -
the intake should be good to 6K, which will be beyond the realm of my normal driving experience. (this is a great OEM maniflod Wyrm)
I'm going to use an AVS2 carb and
I have Hooker headers. Holy man the Hookers on the stock 343 was itself a tremendous difference - AMCs love to breathe!
Mike went with 111 LSA intake in on 108 ICL.
Looks like Mike Nailed the cam
 
Thanks you wyrm.. I am intrigued by the lighter valve train parts you mentioned. I was thinking about my 1.9L Opel engines the other day, cam in head, with the stock hydraulic valve gear that would rev past 8K over and over, all day long with nary a wimper and just some single HiPo valve springs... no fooling. Factory stamped rockers on studs; think I broke 1 rocker in 6-7k miles of racing, never broke a stud. Gotta figure out someday why just adding a pushrod changes things so much for the worse. Of course, the valves are a lot smaller; I need to weigh some vs some stock 318 valves for example.
 
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I had a customer who had a datsun b210 also reved like crazy Racer Brown Cam- he knew datsuns= raced them at bonneville (the OHC motor) 210 was pushrods
Looks like Maurizo nailed that AMC 360 build AMC has 3/8 stem valves like MOPAR LA and they are heavy if you are buying valves why not?
I've done chevy 5/16 stem valves and will also have to check out the LS Stuff
beehive springs help also
Easy to convert an AMC to an adjustable valve train
If chrysler had switched to the AMC when they bought AMC they would have had a Magnum class motor years earlier NIH?
Actually I think the AMC is better than the Magnum
 
Wyrmrider said:
I had a customer who had a datsun b210 also reved like crazy Racer Brown Cam- he knew datsuns= raced them at bonneville (the OHC motor) 210 was pushrods
Looks like Maurizo nailed that AMC 360 build AMC has 3/8 stem valves like MOPAR LA and they are heavy if you are buying valves why not?
I've done chevy 5/16 stem valves and will also have to check out the LS Stuff
beehive springs help also
Easy to convert an AMC to an adjustable valve train
If chrysler had switched to the AMC when they bought AMC they would have had a Magnum class motor years earlier NIH?
Actually I think the AMC is better than the Magnum
Click to expand...
OK, ran against a number of 201's.. a great rally car in its time. Never knew they were pushrod engines.
 
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rumblefish360 said:
I couldn’t agree more after reading that.
IDK about header tube length though.
Never had a old truck to put headers on. I never needed a truck until I got the house.
(El-Camino’s don’t count!)
Click to expand...

Truck headers are easy, the cheap hookers fit fine, drop the starter, shove the drivers side up from the bottom.
Take the oil filter off and drop the passenger side in from the top.
No need to even loosen the motor mounts up.
 
JoesEdge said:
If you need a mechanical fuel pump, then you need to change the front cover to an LA style which means you'll need the LA water pump, crank pulleys, as well as the LA style alternator and power steering if you have power steering.
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When I did my magnum swap, I kept all of the stock magnum front accessories, but without ac. Even adapted the powers steering lines to work with copper compression fittings and an adapter I got in the plumbing section of Lowes. I eventually blew it up and swapped in an la block, and finding new pulley's and a timing cover and water pump can easily added up to more than the cheap electric pump I was running costs, and I honestly liked the serpentine setup better.

What I did was I got the magnum engine in my car running completely stock, and after I got the feel for it I then started to upgrade what I felt would be good. About $1000 total to have it running in my car including $400 for the motor itself. Keeping the truck pan and using stock manifolds can knock that price down for you and leave you with more when you decide if you want more torque or nice chrome valve covers or a fancy ignition, heck even a fuel injection setup. These motors are truck motors from the factory and have good torque stock in my opinion, nothing super crazy but a lot better than your 318. I could roast tires all day with that thing no problem.

I put it in my car, but I'd imagine a truck would be easier. Best thing I've ever done- so much so I've thought about taking my built la 360 and dropping in a stock magnum again.
(I won the award because there was no one else in that class to give it to lol)
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Trucker- have you checked the truck forum?
we have good news on the headers so swap looks good
NM that Datsun was light and was easy to swap brakes - wheels etc from a larger datsun (if my memory was correct heck I can't even remember if it was RWD or not- know it was a 4 speed
 
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