Please forgive me for my lack of knowledge on the magnum motors but I have some questions. First, do you guys see any problems in the future from supercharging a stock bottom ended 360 with roughly 108,000 miles on it?

Also, what kind of boost levels do you guys normally, safely, see on a stock bottom end 360?

The reason I'm asking these questions is because I looked into a supercharger for my Z28 when I had it. I decided not to go that route because everyone kept telling me that a supercharger on a stock LS1 or LT1 would shorten the life of the motor by a hell of a lot. They told me that I would have to rebuild the bottom end with "forged everything" to be able to handle a supercharger reliably and with long engine life.

I'm not looking for racetrack performance here; just some help up hills with a boat behind me. An extra 50-60 horses (or whatever I could safely get) when getting on the interstate, driving up hills, ortowing up hills would be nice. I looked into a heads/cam/intake/TB setup that would cost roughly $4,800 but I thought maybe a supercharger system would be less.

 

That pretty much goes for every car/truck out there.

It's wise to build for boost when an engine does not come boosted from the factory. Yes, technically you can boost any engine, but most deffinetly it will not last as long. Age, mileage, and how much it was beat on are all factors in how well an engine will take boost. Everything is designed to handle just so much pressure from combustion. Adding a blower/turbo/etc will increase that pressure generally to more than the engine can handle. Some engines will outlast others because of differences when they are built. Sometimes you get lucky and can run a stock bottom end with a blower and not have any problems. But other times you install everything, start her up, rev her once or twice and then a rod comes flying through the oil pan. It's almost a crap shoot, really.

Anyway, I'm speaking in general terms here. IndyRam might be able to help out more as he knows more about performance tuning on the 318's/360's than I do.

But I would deffinetly build the engine for boost before i did any of that stuff.

 

Send RM Indy a PM, he's got a boosted truck and really seems to know what he's talking about. Heres a link to his website....
http://www.rm-indy.com/

 

you dont have to do anything to the bottom end to run a supercharger. You just cant run a lot of pressure. Personally I wouldnt go above 5-7psi on the stock bottom end. Idk about the ls1, but the lt1 has 10.5 compression, ours is 9. It gives us a little more room to play. (aside from iron heads vs alum heads)

 

Yep, what indy said. 7psi is all you really need to get a good amount of power out of that blower. Ideal compression for forced induction is 8.5:1 with forged internals, but isnt required if you are smart and do not run too much boost. If you decided to be an idiot and run anymore than 7psi, expect a window in the side of your block from a rod. Remember, you do not want to just slap a blower on there, you will need supporting mods like a larger TB, CAI (if it is not a ram air style blower), larger injectors, possibly a larger fuel pump, and you will want to upgrade your ignition system.

 

HP regardless of how/where you get it will cause parts to wear/break faster if you use it. More you use it the faster the wear/breakage will be.

S/C's start new at 3700 for a 5-6psi Paxton/Vortech kit. That will increase your hp by about 30% roughly. With the mods listed you have a stock truck so that will be about 60rwhp gain give or take 5.
Prochargerkits start at 4600 but include an air to air intercooler and give 7-8psi on the base kit (P-1SC). Youdont have to pull timing from a stock computer with this kit so it makes a fair bit more hp. You can expect50% increase in power for close to 90rwhp.

Bottom end you dont really have to worry about, easily takes 400rwhp (500+crank) without an issue. What you will have issue with is the stock headgaskets. They cant take more than 8psi boost safely. If you have had any detonation while towing na up n down hills then chances are the headgaskets wont take more than 5-6psi.
I wouldnt add a s/c if your compression is not even and good across all cylinders

Do you really need a s/c or is it a good choice?

What size tires do you have?
Gears?
How heavy is the trailer?

If you have 33" tires or larger and have either 3.55 or 3.91 gears then you need to go to taller gears. 456 would be a good choice with you towing in hilly areas.
Adding a few more hp after the gears Im sure will have your truck towing like a champ and save your gas mileage aswell compared to a s/c motor.
52mm tb, 1.7rr and long tube headers would help you out a fair bit.

Adding a s/cto a stock motor you will see a power lossof about 10rwhp (depending on s/c & pulley dia)fromidle to 2200rpms roughly. Withthings like cam, intake, tb and headsthat 10hp loss isnt really noticed, when stock, it can turn it into a slug off the line.
Boost is progressive on a centrifugal s/c so you need rpms to make hp.If you keep it in boost all the time then you mileage will suffer big time.

 

Cool, thanks guys. It has 31.5" tires, 3.55 gears, and the boat I pull with it is a 19 foot fish/ski with a 175 HP Mercury outboard. Not huge, but it is heavier than a bass boat because of the deeper hull.

I don't think I'll go with FI on my motor because of the mileage on it. If it only had 40-50,000 miles on it I would really consider it but I don't want to worry about it. I was just thinking that maybe superchargers were a lot safer on these motors than other stock motors because of something done at the factory or whatever.

Besides, if I went with a good heads/cam/intake/TB setup I would pretty much be rebuilding half of the motor and making more power so I would be killing two birds with one stone, so to speak. Thanks for the info though.

 

I have a 17 footer that I have to tow twice a year. To get up from the dock I have a 35-40* incline I have to go up thats about 100 feet long all gravel. I have had no problem with that.