How weak are the 302 blocks?

Discussion in '94-95 5.0 - Specific' started by yleefox, May 14, 2007.

  1. yleefox

    yleefox New Member

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    I've been reading a lot about the 5.0 Mustangs and it appears the blocks are somewhat weak. My question is how weak? What is considered to be the reasonable limit, horsepower wise, before one could expect to have block failure? Anyone know?

    Thanks
    Yleefox
     
  2. wytstang

    wytstang Well-Known Member

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    The closer to 500rwhp/tq the better the chances of block failure. But if it's a street car that doesn't see that 500 mark to often it can live a long life. But if you have a heavy foot and are always spinning the motor to make 500 horses then yeah it's just a matter of time.
     
  3. 91paxmustang

    91paxmustang Guest

    I had a 84 block non-roller that started to crack at a few places where the head bolts are, towards the inside of the cylinder wall. that was a fairly stock setup, maybe at best 230 hp. I replaced it with a 90's roller block with it mildly modded, hci. and no probs., I think if you are planning on making a car anywhere near 400+ hp you should get a main supports. My 91 gt has a dss block and has held up excellent. dssracing.com.
     
  4. ha ha... what are you nuts?

    302W is near indestructible...

    My buddy has one w/ over 600,000 miles on the non working odometer. (stopped working about a year ago)

    So don't try n tell me its a weak motor... take care of it, it will rock on and out live you...
     
  5. Hicks

    Hicks Well-Known Member

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    Everyone i know says 550 is the breaking point usualy, but man... a 5.0 has SICK potential!
     
  6. 91paxmustang

    91paxmustang Guest

    What i was saying was my 84 block had 230hp at best, not that thats all they can hold. You Just need a good bottom end to run 400+ hp.
     
  7. Stangbangin

    Stangbangin Active Member

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    302 blocks are good for street cars...if you want to get serious with any power adder you'll need an aftermarket block. I split mine down the middle with whats in my sig and a 200 shot so do the math...probably around 500 with the spray...mild street setup the factory block is fine...but if down the road you'll want more aftermarket is the only way.
     
  8. ripper

    ripper Well-Known Member

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    Hey stang check this out. Its my wifes 95 with same sunroof as yours :thumb:



    [attachment deleted by admin]
     
  9. 94yellowgt

    94yellowgt Active Member

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    I have always heard 450 rwhp in the highest to go and last. The stock internals will out last the block on a healthy motor. I know I have a ticking time bomb with just over 500 hp.
     
  10. Stangbangin

    Stangbangin Active Member

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    aww crap I have a chick car.....f#ck
     
  11. nah... his wife has a Man's car...

    lol
     
  12. muscle mustangs and fast fords "hooligan" has a turbo 347 in it makin 430 whp and they cracked theirs in half. Its really hard to say, i have heard 550 whp, and i have heard after 400whp. On my last forum their was a guy makin 420 whp with a procharger and a top end kit and he cracked his...so its hard to say.
     
  13. Paul

    Paul Legend

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    There is no pre-defined limit. It is based on a lot of things like rpm, detonation, quality of the balance of the internals, and dumb luck. I've seen them split at 400 rwhp, and I've had a friend who had his stock-block, stock-crank 306 make 691 rwhp for a year before it finally split down the valley - and it was abused regularly.

    A good rule of thumb is simply this: if you're making big power for any length of time with a stock block, you're on borrowed time.

    Paul.
     
  14. Stangbangin

    Stangbangin Active Member

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    I was building a 302 once in my garage and sneezed on it too hard and it split the lifter valley.....true story.
     
  15. ha i sometimes wonder why i like mustangs so much. so many weak points, but i believe its just because i know the weak points, where as other cars look more appealing because you dont know their weak points. Gotta love tha car though, aint nothin like a Stang. Did you really split a block haha?
     
  16. bybyz06

    bybyz06 New Member

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    When I had my ProCharger D1-SC on my 347 stroker I asked ProCharger for the 18lb. pulley (I was putting down 500rwhp at the time with the current setup), and the guy didn't want to sell me the smaller pulley. He said that unless I plan on rebuilding the motor in a short time that heading over 500rwhp was a sure fire way to end the block. He said that making the 500rwhp that I was making at the time that I was on borrowed time.

    bybyz06
     
  17. haha at least he didn't just let you sink your own boat. The hooligan actually has a turbo set up, sorry my bad. They put a soft tune in it and they put a main cap girdle on it and it survived for a year like that. They said that the main cap girdle more than likely is why it lasted for a year.