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SUPERCHARGER??? 350 buildups

Discussion in '1973-1991 K5 Blazer | Truck | Suburban' started by CarsonRoen, May 22, 2000.

  1. CarsonRoen

    CarsonRoen Registered Member

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    i have a 73 Jimmy with a 350 in it. I need more power because i want to put 38.5's on it and the stock 350 won't get the job done. some people have told me that a supersharger would be great because of the low ratio and i could save later on gas that way. But now i desided to go to all of you for the real answers. What superchargers are good for my car if any? what other things can i do: headers, ignition, what? i already have a four barrel Holley, but that is about it. I need some pointers hear from the people that have done it before. thanks.
     
  2. Bigd

    Bigd 1/2 ton status

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    For the price of a charger maybe even less you could build a pretty nice big block. witch will have better low end torque then then a supercharged 350.Less parts too break easier too mantain.If you need the power of the supercharger too get you moving your not going too get better MPG anyways.Have you priced a supercharger system lately?They say easy bolt on but on a older truck like yours it won't be.New pulleys w/serpentine belt you will also need all the alt,power st,ac related brackets too line this new belt system up too.And depending on your current motors condition and compression ratio you might have too rebuild it anyways before you could use a supercharger.Just my opnion but i would go big block and keep it simple.
     
  3. mpikas

    mpikas Registered Member

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    Blowers rank high for coolness factor, but I don’t think that I’d want one on anything that has to be reliable and bulletproof.

    Assuming that you’ve got them sized right, especially with a positive displacement roots or whipplecharger you can build a lot of low end grunt, but you’ll also build a truck that will tend to overheat. Building more HP always means needing better cooling, but when you compress a gas it heats up. Add to that any frictional losses that get added to the intake charge as heat, and then the fact that any action off road, especially rock crawling happens at a relatively low speed so that cooling isn’t it’s best, you’re bound to have problems.

    Race cars are a good example of this also, when was the last time that you saw a supercharged car other then a drag type vehicle. It’s fine for a few seconds at a time, but when you demand power for a longer time period like road racing, the heat and stress tends to take out engine parts (there is more then one person in my car club that has tried it).

    I’d shoot for a good, mild engine (may want to build up what you have), or if you can afford it a big block is always nice, but really, what you need is steeper gears.
     
  4. getsome

    getsome 1/2 ton status

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    You also need to remember that if you decide on a supercharger you will need to change the compresion ratio to something like 7to1 or 8to1. I personally would build(or have one built) a stout small block or soild big block with 4.88 or 5.13 gears. Let us know what you decide.

    Getsome
     
  5. bablazer73

    bablazer73 1/2 ton status

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    Reliable? superchargers? look under the hood of a haulin truck! detroit diesels with 8-71 and 2 turbo chargers!! 200,000. miles before a rebuild! got a 4 cylinder forklift with a 4-71 on it! lifts 25,000 lbs and moves it. no prob! Yes, supercharged engines to some degree need more attention when being built. depending on what you trying to do. put a 6-71 or 8-71 on a 350? no! 4-71 ? works good. B@M has a complete kit, with pulleys and brackets. have one on the engine going in my '73 blazer. some parts need attention. works good with stock compression 8.5-9.5 and with a small cam, headers and exaust a big difference can be felt. HOWEVER. in your case, I think axel gears should be the first thing changed to "compensate" for the tires. just adding more power will put more strain on the trans and driveshafts to make it move! think gears first. may cost more if you cant do them yourself, but worth the cost!

    your right. I don't understand the jeep thing!
     
  6. dumbfounded

    dumbfounded 1/2 ton status

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    Well unfortunately the diesels were made for the abuse. the block and heads were made for 20+:1 compression hense the lack of sparkplugs, try that with your 350. I do agree the sound forced induction is great. High cool factor. As for reliability you have to pay dearly for that. the supercharger will wear out but takes a long time. What the problem is the bottom end will have to be built tough. Just look at the thunderbird SC (ford yuck) but here is a reliable stock supercharged vehicle b/c it was made for it. Low compression is a must and a heavy duty cooling system is in order. I'm not all that practical and yes a big block would be the best choice but if you need the power who cares. Go for the blow job. As for gas mileage not. Turbos use spent gasses for their supply but a sc will rob power from the crank which in turn puts more than enough gas and air to make up for itself. But in a full size blazer you wont see 30mpg anyways. Look at it another way build a tough motor to take the abuse throw the blower on it and it will blow your mind, naturally after a while you'll get used to it so it won't feel as fast and all you have to do is change a pulley get more boost and another kick in the ass. Try getting more from that big block that just cost you thousands. As for racing cars not having sc's It's probably due to regulations and rules b/c with corporate sponsors they can and will find reliability and a cooling system to boot.

    Blood, sweat, tears, and lots of money is what keeps the k5 alive.
     
  7. Bigd

    Bigd 1/2 ton status

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    Still say build a big block.Should be able too build a nice motor for two thousand.Blowers 2500 to 3500.If you still need another kick in the pants buy a four hundred dollar nitrous kit.The switching pulleys will work to a extent till you get too about 12-15 psi's of booost then you'll need more expensive upgrades.Like i said just my opinion.
     

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