BBC & Boost
we made 35# boost on the dyno and didn't have any problems, but we do run the Big M block with the 4 extra studs in the lifter valley..
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1966 Chevy II twin turbo LS3 project
2016 Z07 Carbon
1966 Chevy II twin turbo LS3 project
2016 Z07 Carbon
Teching In
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Not to sound rude but what are you trying to put 30lbs through it for??? To put that kind of boost through a big block (ie. 454) you need some serious airflow like a 14-71 overdriven and spun to 7000+RPM or a very large turbo w/ a huge exhaust a/r and the motor has to be able to withstand those kinds of cylinder pressures. At that level you are 200% above atmospheric pressure (2 bar) and if you had a big block doing that you would be making an insane amount of power. What is this going into and what are youre supporting modifications? Not saying that it can't be done but it has to be done right.
Originally Posted by ShawnF
Not to sound rude but what are you trying to put 30lbs through it for??? To put that kind of boost through a big block (ie. 454)
you need some serious airflow like a 14-71 overdriven and spun to 7000+RPM or a very large turbo w/ a huge exhaust a/r
and the motor has to be able to withstand those kinds of cylinder pressures. At that level you are 200% above atmospheric pressure (2 bar) and if you had a big block doing that you would be making an insane amount of power.
What is this going into and what are youre supporting modifications? Not saying that it can't be done but it has to be done right.
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1966 Chevy II twin turbo LS3 project
2016 Z07 Carbon
1966 Chevy II twin turbo LS3 project
2016 Z07 Carbon
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He was asking Evoguy why he'd do this, not Brady. Brady has a known speed sickness, maybe Evojuices does too? Asking huge power of a stock block could be big trouble. If you're willing to risk it, please....please..take video. and wear safety glasses.
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Originally Posted by AutoRoc
He was asking Evoguy why he'd do this, not Brady. Brady has a known speed sickness, maybe Evojuices does too? Asking huge power of a stock block could be big trouble. If you're willing to risk it, please....please..take video. and wear safety glasses.
if you build a big block that makes even 20 psi of boost you should use an after market block a stock block is good to around 1000 horse NA.
Stock BBC's from GM (Non Dart/World Blocks) are good for right at a 1000 before you start making the Cylinders move like someone on dancing with the starts.
How much power are you wanting? Billet 4 bolt splayed caps, head studs, etc are what you are using right?
How much power are you wanting? Billet 4 bolt splayed caps, head studs, etc are what you are using right?
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On The Tree
Joined: Feb 2006
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From: San Diego/Los Angeles CA
Originally Posted by ShawnF
Not to sound rude but what are you trying to put 30lbs through it for??? To put that kind of boost through a big block (ie. 454) you need some serious airflow like a 14-71 overdriven and spun to 7000+RPM or a very large turbo w/ a huge exhaust a/r and the motor has to be able to withstand those kinds of cylinder pressures. At that level you are 200% above atmospheric pressure (2 bar) and if you had a big block doing that you would be making an insane amount of power. What is this going into and what are youre supporting modifications? Not saying that it can't be done but it has to be done right.
The Class is going as fast as 7.80's at 175.
Most cars are 600ci+ Big blocks on 3 stages of nitrous
Thread Starter
On The Tree
Joined: Feb 2006
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From: San Diego/Los Angeles CA
Originally Posted by MADMAN
Spend the money on a good block.
Madman who do you think makes a better block, Brodix,Dart, or Merlin?
Thread Starter
On The Tree
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From: San Diego/Los Angeles CA
Originally Posted by BigBronco
You can not go wrong with a Dart or World piece. You can even order a GM Bowtie Block. That will also hold up very well.
Any idea how much more an iron big block is than aluminum. I was already close to my 3500lb max with the old iron SBC setup.
At the power level your looking at not very many people (including myself) would recomend going down the stock block path. But, your obviously looking for specific information on how far the stock blocks have actually been pushed.
I'm sure the blown alcohol guy's have pushed the stock blocks higher, but from my personal experience the car shown in my Avatar hit a 8.29 at 3500 pounds on gas with an 8:71 blower shop blower and two plates. Thats over 1400 HP. Even though the engine I built was done on a budget I would not recomend risking parts or worse on an old mark IV BBC. Plus, once all of the machine work is completed on getting the old block up to the task the money difference is not that much (vs a DART big M or eqv). Good luck.
I'm sure the blown alcohol guy's have pushed the stock blocks higher, but from my personal experience the car shown in my Avatar hit a 8.29 at 3500 pounds on gas with an 8:71 blower shop blower and two plates. Thats over 1400 HP. Even though the engine I built was done on a budget I would not recomend risking parts or worse on an old mark IV BBC. Plus, once all of the machine work is completed on getting the old block up to the task the money difference is not that much (vs a DART big M or eqv). Good luck.
