1997 5.9L Magnum Roots Supercharging and Fitment

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SamTech15

SamTech15

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Hey guys, I have a 1966 Dodge Dart and I have a brand new 5.9L magnum engine out of my girlfriends wrecked 1997 Ram 2500(Long Story). Basically what I am wondering is 1. Will this engine take a low boost roots supercharger given its low factory compression (5-10psi for boost) and survive 2. Will a intake made for an older non-magnum engine(I found a roots supercharger kit with intake but unsure if it fits Magnum engines, wondering if there is an aftermarket option by word of mouth as I can't find one, and finally 3. If I say wanted to put a smaller pulley on the supercharger and push more boost in the future, can I just get away with rods and general bottom end strengthening or will the entire motor just give up on life?

I've tried to do research myself but there aren't a whole lot of people supercharging these engines with roots chargers, mostly paxtons or full on prochargers it seems. Much less putting them in an old car with no ECM to toy with. Thanks for any help guys, I know it's a speculative topic.
 
Problem with super chargers is the strain on the crankshaft snout, other than that, oem magnum stuff will handle 10 psi no problem. With the exception of high strength fasteners and upgraded head gaskets. It must be tuned correctly where it has lots of fuel and retarded ignition advance when in boost. So a quality forged crankshaft is a must.
 
Thanks for the vote of confidence T56Max, I am debating just getting the whole forged rotating assembly and cranking the boost til the factory heads can't support it anymore. The stock setup was just going to be a proof of confidence as I build my suspension and drivetrain. We will see what the wallet gods decide.....

*proof of concept not confidence
 
The la and mag intake bolts are at different angles. There's some jigs floating around to redrill it, and Hughes offers the service too.
 
SamTech15 said:
Hey guys, I have a 1966 Dodge Dart and I have a brand new 5.9L magnum engine out of my girlfriends wrecked 1997 Ram 2500(Long Story). Basically what I am wondering is 1. Will this engine take a low boost roots supercharger given its low factory compression (5-10psi for boost) and survive 2. Will a intake made for an older non-magnum engine(I found a roots supercharger kit with intake but unsure if it fits Magnum engines, wondering if there is an aftermarket option by word of mouth as I can't find one, and finally 3. If I say wanted to put a smaller pulley on the supercharger and push more boost in the future, can I just get away with rods and general bottom end strengthening or will the entire motor just give up on life?

I've tried to do research myself but there aren't a whole lot of people supercharging these engines with roots chargers, mostly paxtons or full on prochargers it seems. Much less putting them in an old car with no ECM to toy with. Thanks for any help guys, I know it's a speculative topic.
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I saw a nice set-up on a guys truck one time. It was air-to-air intercooled, which could be a challenge in an a-body. He claimed it not only allowed him to boost it harder, but that it helped the motor live longer by avoiding detonation. He did have a custom reflash on his ECM. The install looked like the factory did it. If I remember correctly he was spinning out just over 500+hp.
 
Yeah I was reading about that Pascamp, does anyone know of a set of better flowing aftermarket heads with both bolt patterns, or a set of heads with LA bolt style and magnum head gasket fitment? I am aware of a set of stock style magnum heads with both patterns drilled out, but I would rather not buy a set of heads just for a bolt pattern when I have brand new ones sitting on the block as it is.
 
jbc426 said:
I saw a nice set-up on a guys truck one time. It was air-to-air intercooled, which could be a challenge in an a-body. He claimed it not only allowed him to boost it harder, but that it helped the motor live longer by avoiding detonation. He did have a custom reflash on his ECM. The install looked like the factory did it. If I remember correctly he was spinning out just over 500+hp.
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jbc426 I am not against removing the grill and fender wells to get the cooling I need if that would let me boost harder lol. I would love to have this thing pushing 15-20psi even if it means overdriving it with a smaller pulley later on. Superchargers are just cool to me with how mechanical they are. Every soccer mom has a turbo on their Hyundai out the factory nowadays.
 
SamTech15 said:
jbc426 I am not against removing the grill and fender wells to get the cooling I need if that would let me boost harder lol. I would love to have this thing pushing 15-20psi even if it means overdriving it with a smaller pulley later on. Superchargers are just cool to me with how mechanical they are. Every soccer mom has a turbo on their Hyundai out the factory nowadays.
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if memory serves, he was limited to 11 or 12 psi due to the bottom end etc. I believe anything above that is race fuel pressure on these motors, but I'm no expert.
 
Ah the infamous bottom end. I am curious though, was his motor also stock and pushing 500hp? I have talked to the supercharger dealer and they insist I can only push 5psi or so, but I feel like with how low the compression is on these magnums I could push more.
 
I have a set of RHS heads on my 360 that are a closed chamber magnum design that use LA intake and shaft rockers. Bought them brand new and put them on a magnum block going through the transition years so I already had pressurized oil ports to the heads for the shafts. Hughes will drill a magnum head for la intake if you're interested.

The supercharger company may be right, a 360 may only hold 5 psi at 6000 rpm (for example) using their compressor because that is all it can supply. If you overdrive it, the compressor speed may be higher than it was designed/rated for.
 
MiradaMegaCab said:
What is the blower size, manufacturer and what's included in the kit?
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It is a full kit from Dyer Blowers Mirada and it includes the blower, intake, pulleys, belt, basically a whole supercharger ready to go kit without carbs. The size would be a 671, which I still have no idea what that really means besides size.

T56MaxTorq said:
The supercharger company may be right, a 360 may only hold 5 psi at 6000 rpm (for example) using their compressor because that is all it can supply. If you overdrive it, the compressor speed may be higher than it was designed/rated for.
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They said the low boost was due to the fact the bottom end would not hold up to more than that, but if I had forged rotating assembly I could push within reason "As much as I want". They did state with a 360 it would be under driven, but I am looking for a blower setup I could potentially move to a big block or stroked out small block. Any idea what hughes would charge for the re-drill? I have a friend that does cylinder head machine work but I know he does not have a jig of any kind to do it. Some people claim they used slanted washers on the bolts to fit the straight down Magnum bolt pattern to the slanted LA intake, but Im not sure if I want to play around with a boosted setups intake bolts, stuff happens.
 
I pushed a 318 to 10 psi on e85 with stock internals (upgraded fasteners) with a turbo. They may be right considering the load on the crank is significant. Forged crank would fix that. Pistons and rods are highly questionable at 15-20 like you're thinking. But it's all in the tune
 
I have a carburetor guy who all he does all day is rebuild and set up carbs, from singles to six packs etc so Im gonna have him tune it, I am not that good with performance tuning. I understand the crankshaft bit and may just take the plunge and get a forged bottom end. The car wont be a dedicated racer so Im hoping to get years of life from this thing, might as well do it right the first time. I appreciate all of your folks insight and experience.
 
Just catching up on this thread. I'm pretty well versed in 6-71/8-71 builds from "back in the day". With an intercooler you would be damn lucky to push 10psi on pump gas. Without you're probably safe in the 6psi range. Old school roots blowers generate crazy heat. Truthfully after 6-8psi it's a waste. You hardly make any more power. Most people aren't familiar with these anymore. A roots build is usually in the 6-7 CR range coupled with a cam that bleeds cylinder pressure. The crank snout deal is real too.

They look cool, but they are not in the same ballpark as centrifugals, helix, or turbos.
 
The Magnum engine is rated at a 9.0-1 ratio which is at least 1pt. higher than the max you want to super charge a cast piston and crank set up. This is where the "Limits" come in.

Add a much thicker gasket for marginal added boost because the gasket becomes the seeker link in pressuring above the Mello 5psi suggested limit of the 9.0-1 ratio.

Roots chargers are excellent at low end while the snails are looking at the big end.

IMO, limit yourself to 8 & no more than 10 psi of well tuned parts and you will be fine. Even small amounts of boost add excellent and amazing amount of power.
 
OH! MoPar use to offer a Magnum head with LA intakes heads hole pattern drilled.

As stated earlier, a place like Hughesengines can do the work for you in addition to other work.
 
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The Blower Shop, BDS and Teague offer 71 series air to water intercoolers. Unless you're going to be running your blower at high boost/RPM's, I'd pass on running one.

I'd recommend cutting a double keyway in the crank and harmonic balancer and run full groove main bearings to provide full time oiling to the rod bearings.
 
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