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how much power can a stock short block 350 handle?

Discussion in 'The Garage' started by Jonny-K5, Jul 7, 2004.

  1. Jonny-K5

    Jonny-K5 1/2 ton status

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    i want to do some mods to a 350 powered pickup i have. i basically want to make as much power as i can for 1/4 mile.
    how much can i get away with before i have to start tearing into the short block? the engine has about 100 miles on it, stock spec rebuild with quality parts, 4 bolt main.i'd like to leave the stock dished pistons and cast crank.
     
  2. Z3PR

    Z3PR Banned

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    Besides the cam, intake, and headers, you may want too look into heads. If you currrently have 76cc heads, think 64cc. that'll bring up your compression. If you're just talking a 1/4 mile run, well, NOS is hard too beat for a quick burst of power. Rear gears are a big factor in racing also.
     
  3. fortcollinsram

    fortcollinsram 1/2 ton status

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    I would not thing anyhting over 400hp on the stock short block would be very reliable at all...The stock rotating assemblies leave much to be desired when it comes to high-rpm, high horse power build-ups..

    Chris
     
  4. 88Silverado

    88Silverado 1/2 ton status

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    As was said, the stock bottom end is good into the upper 300+. Im running about 330hp on my 4-bolt main and it seed 6500rpm's quite often. Heres a pretty good link on a basic performance build using a stock Gm crate motor as a starting point.
    Goodwrench Buildup
     
  5. diesel4me

    diesel4me 1 ton status Premium Member

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    A better question might be "How long will it run"?.You can get tremendous horsepower from a small block chevy--but after 400 hp,as other posts have stated,it starts to become a reliability issue--even race motors blow up fairly quickly even though they are put together with the best of care and the best parts--there's a lot to be said for longevity and reliability both on and off the road. /forums/images/graemlins/crazy.gif
     
  6. 84_Chevy_K10

    84_Chevy_K10 Banned

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    A good balance job and high quality fasteners goes a long way here.

    Using a rod bolt stretch gauge instead of torquing them helps, too.
     
  7. backcountry

    backcountry 1/2 ton status

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    In all my engines I install a MSD 6AL spark box. (Except for my boat witch is a MSD 6M-2) I do so to keep my motors from reving past 5000 rpm's. The small block Chevy can go beyond this by far, however reliability will suffer in the long run, especially in a stock shortblock. A 4 bolt and for that matter a 2 bolt main block will handle quite a bit of HP and Torque if it not reved to high.

    As far a heads go, I like these; http://www.jegs.com/cgi-bin/ncommerce3/ProductDisplay?prrfnbr=2441&prmenbr=361

    /forums/images/graemlins/thumb.gif /forums/images/graemlins/peace.gif
     
  8. 84_Chevy_K10

    84_Chevy_K10 Banned

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    I agree, and I have a 5,000 RPM pill in my MSD 6AL as well. No reason to see any higher RPM than that, although it does ruin the fun in those muddy sections.
     
  9. big83chevy4x4

    big83chevy4x4 3/4 ton status

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    theres a few cirle track guys here that are running 500+ on a stock 4 bolt block. not sure what fasterners, im sure not stock /forums/images/graemlins/yikes.gif these motors run at 7000+ rpm all day long

    not me though. 6000 is plenty high for me
     
  10. Ryan B.

    Ryan B. 3/4 ton status GMOTM Winner

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    boost it & juice it.
     
  11. fortcollinsram

    fortcollinsram 1/2 ton status

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    [ QUOTE ]
    theres a few cirle track guys here that are running 500+ on a stock 4 bolt block. not sure what fasterners, im sure not stock /forums/images/graemlins/yikes.gif these motors run at 7000+ rpm all day long. not me though. 6000 is plenty high for me

    [/ QUOTE ]

    I have NO questions that the stock block are capable of over 500hp. But I would like to see a stock rotating assemby last at 600hp. The 355 I am building is just a stock block, splayed 4-bolt mains but it has ALL the goodies in the rotating assembly...Scat Forged crank, Lunati H-beam rods and ross pistons /forums/images/graemlins/whistling.gif /forums/images/graemlins/whistling.gif We are planning on 600hp all day long (via the turbo set-up). I have no hold-backs using my stock block for this application...

    Chris
     
  12. Ryan B.

    Ryan B. 3/4 ton status GMOTM Winner

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    I read an artice not too long ago that chevy hi performance magazine did a junkyard rebuild on a 350 and starting adding nitrous...
    I think they basically gapped the rings for nitrous and added a camshaft... baseline the engine dyno'd right about 300 horsepower. not bad for a junkyard 350.
    then added 100 shot.. which added a true 100 horsepower.
    went to a 200 shot...
    then a 300 shot... it put down 600 hp on a junkyard engine.
    They thought they might have hurt the engine so they pulled it on the dyno again just on the motor... and it put down 315 horsepower. how'd they get an extra 15 horse?
    Then i think they went to jet it for a 400 shot and decided to purge the nitrous into the engine at idle which threw a rod and ended the test.
    point is they achieved a short burst of 600 horsepower out of very cheap junkyard engine.
     
  13. Jonny-K5

    Jonny-K5 1/2 ton status

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    thanks for all the replies. this is what i was shooting for. around 400 hp with cam intake carb alum heads and headers.

    what size intake runners would be best for this setup? i've seen them from 170 to 220. im thinking 200 would be good. am i right? also , is there any reason to go with angled plugs instead of straight? besides header clearance.
     
  14. Z3PR

    Z3PR Banned

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    [ QUOTE ]
    thanks for all the replies. this is what i was shooting for. around 400 hp with cam intake carb alum heads and headers.

    what size intake runners would be best for this setup? i've seen them from 170 to 220. im thinking 200 would be good. am i right? also , is there any reason to go with angled plugs instead of straight? besides header clearance.

    [/ QUOTE ] My choice /forums/images/graemlins/waytogo.gif /forums/images/graemlins/waytogo.gif
     
  15. branrat

    branrat Registered Member

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    400-425 HP on mostly stock cast parts
    More than that requires forged

    I build my 383 to be right about 400 HP using Cast, Nodular iron, Hypertectic, It cost around $2500 & I am quite happy. If i went with bigger HP then It would have probably cost me $1000+ for power that I really wouldnt use.[too high of a torque band]

    Remember Cubic Inches = Cubic Money

    Stop on over to Chevytalk.com & look up some good engine combos. or try this one...

    http://www.ryanscarpage.50megs.com/combos1.html
     
  16. Jonny-K5

    Jonny-K5 1/2 ton status

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    thanks for the link, that gives me alot of food for thought.
    heres another question, what are the stock rockers good til?(RPM) what would be a cheap uprgade for this application.
     
  17. branrat

    branrat Registered Member

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    The stock rockers are good for about a .500 lift & could rev as high as the valve springs would handle, but the weak link is the studs. I would upgrade to 7/16 screw in studs & if i was going to really rev I would add a stud girdle with tall valve covers.

    If I was really going to set up a top end I would use Air Flow Research 195 heads W/64cc chambers & straight plugs. They come with screw in studs & oversize valves. I would then top them off with Comp Magnum roller rockers. Of course were talking about $1500 here....
     
  18. backcountry

    backcountry 1/2 ton status

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    [ QUOTE ]
    I read an artice not too long ago that chevy hi performance magazine did a junkyard rebuild on a 350 and starting adding nitrous...
    I think they basically gapped the rings for nitrous and added a camshaft... baseline the engine dyno'd right about 300 horsepower. not bad for a junkyard 350.
    then added 100 shot.. which added a true 100 horsepower.
    went to a 200 shot...
    then a 300 shot... it put down 600 hp on a junkyard engine.
    They thought they might have hurt the engine so they pulled it on the dyno again just on the motor... and it put down 315 horsepower. how'd they get an extra 15 horse?
    Then i think they went to jet it for a 400 shot and decided to purge the nitrous into the engine at idle which threw a rod and ended the test.
    point is they achieved a short burst of 600 horsepower out of very cheap junkyard engine.

    [/ QUOTE ]

    I read the same article. Great one btw!

    If he just wants just one run at the 1/4 mile crank it up to 600Hp.

    Don't know about you guy, but when I'm deep in the woods I want reliability not HP. /forums/images/graemlins/waytogo.gif /forums/images/graemlins/peace.gif
     
  19. Jonny-K5

    Jonny-K5 1/2 ton status

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    [ QUOTE ]
    If he just wants just one run at the 1/4 mile crank it up to 600Hp.

    Don't know about you guy, but when I'm deep in the woods I want reliability not HP.

    [/ QUOTE ]


    this truck will never see the deep woods.its 2wd and its only got about 2 inches of ground clearance under the front end /forums/images/graemlins/wink.gif
    my blazer as a reliable stock tbi350 in it. i feel the same way. but this motor will be for fun on the road, i think im going to shoot for about 400,with no juice. i want it to last for more than a few passes down the 1/4 mile.
     
  20. backcountry

    backcountry 1/2 ton status

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    That sound good! Your motor should run just fine and be reliable. /forums/images/graemlins/waytogo.gif /forums/images/graemlins/peace.gif
     

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