Nitrious , an 71 302 block

Discussion in 'New Members Forum' started by lightspeed, Feb 22, 2013.

  1. lightspeed

    lightspeed Member

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    i am using my 71 302 block , 2 bolt main, it is now 331 stroker , 450 HP-450 TQ in gross messurment , i have an Eagle steel stroker crank , Eagle H-Beam Rod,s and JE. Forged piston,s i like to spray 100 shoot to 150 shot on nitrious , i fell good about internal,s taking it , but i heard the block i am using , likes to split , just under ,where the cam shaft goes to lower main,s , i am not sure if adding a main-bolt girdle an a lifter valley girdle will help?????? how much can the block take safely?????? i feel like my block is the weak link , 450 HP Gross was real good in 2000, but know not so much in 2013...
     
  2. MaverickDan

    MaverickDan I wanna go fast!!!

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    A main girdle and valley girdle wont stop the block from splitting, it'll just keep all the parts in a nice neat pile when it does split. Time to upgrade to a dart block!
     
  3. lightspeed

    lightspeed Member

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    well i know a Dart block would be a good answer , but the $$$$$ , and if i did that i would build an whole new stroker engine , with force induction of some type , i gusses i want to know how much can my block take, i am looking for the cheap power adder of nitrous..
     
  4. bmcdaniel

    bmcdaniel Senile Member

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    Back when I ran nitrous I used a Jacobs Nitrous Mastermind to babysit the engine. It controls what rpm the nitrous starts, ramps it up so it's not so hard on the engine, retards ignition, rev limiter , monitors fuel pressure, etc. I ran a 125 shot with stock crank and rods and cast pistons for about 13 years without issue.
     
  5. MaverickDan

    MaverickDan I wanna go fast!!!

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    Ford 302 blocks split at about 500hp. I don't know if thats fwhp or rwhp though, I've heard keeping it under 6000rpm helps keep them together. My car was making roughly 500 rwhp, my block was holding up well before the piston let go. I think you'll be alright unless this is going to be raced/sprayed a lot then you may have issues.
     
  6. lightspeed

    lightspeed Member

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    how much power did your engine make on it own ,before u sprayed the 125shot??? The jacob,s nitrous mastermind ,did u use a mecanical fuel pump of the block?? did it monitor the fuel pressure of the pump or fuel solnoids of the nitrous kit or both??? what year and displasment block did you use??
     
  7. lightspeed

    lightspeed Member

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    my engine spins 6800 RPM shifts.....
     
  8. fordman57

    fordman57 Member

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    block

    You should be fine, the blocks that split are the factory roller cam blocks
    85 and up. The newer blocks are thinner.
     
  9. groberts101

    groberts101 Member

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    I agree with that as well. Even then though.. no one can say with all certianty that it will or that it won't since they come apart for various reasons and under varying applications. I do know that nitrous shots can suddenly stress the bejesus out of a block that's already being pushed to near its margin of failure though.. and the various controllers can and do ease the shock that they see.

    For example of how sporadic these little motors can be. My buddy had a 5.0 fox about 6-7 years ago that was pushing over 550 horsepower at the WHEELS on the STOCK block with a small pullied V1.XX(something or another) and everyone kept telling him he was running on barrowed time with his setup. They(including me) were all wrong as he later sold the car to another guy that pushed it even further after a freshening and head work to "supposedly" near 700 at the wheels with more boost(well over 20psi). Don't know how accurate those numbers were but I did talk to a couple guys who raced against and saw the car run much bigger MPH on the same rear gear than my buddy had on the previous combo. Major jumps in MPH usually equate to pretty big power gains so he was definately making more power.

    On the other side of the coin.. a friends friend.. had a nitrous hit of 175 on a relatively mild older vintage 302(maybe early 70 something block?) which probably only made 375'ish at the crank in an 85 T-bird and that thing didn't even last a season until it cracked the block so bad that the mount broke off the frame when it let go.

    And the list goes on as there are literally TONS of those little motors running around St Paul during the summer and many are far beyond what these little blocks are supposed to take. I do hear them talk about so and so's car splitting the block once in a while though.. so it does happen on ocassion and shouldn't be taken lightly for the amount of damage it causes to the wallet.
     
  10. bmcdaniel

    bmcdaniel Senile Member

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    Don't know what the engine made N/A. Had hogged out 351W heads, E'brock Performer intake and cam, 600 Holley, headers. Pretty tame. Carter Street/Strip mechanical pump. Fuel pressure switch was in the Y-block that fed the carb and fuel solenoid. '78 short block built by RHS back when they used to build engines.
     
  11. lightspeed

    lightspeed Member

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    to be honest , i can,t afford to lose this engine , i am proud that i totaly put it toghther myself in 2000 and it is running strong in 2013. just looking for more HP ,with out building a new motor , or losing the one i have 331 ci.
     

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