**600hp sbm block limit? Or is it bs!!**

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64physhy said:
I think a stud girdle would increase how far you could push it. Once I get the cage and stuff in mine, I plan on juicing it with a 100 or 150 shot, which will push it well above 600HP. I only spin mine a little past 6K.
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I never used a stud girdle and put in 400hp on 2 stgs, i have broke cranks, pushed out gaskets, but not the block using n2o, but i leave off idle on the system and that seems to play mayhem on the bearings which will make them need changing more often.
 
pettybludart said:
Louis I had went to the track 3 weeks ago.I unload the car and it was running rough,so I thought it was due to the cold weather(was 12*)outside.When I checked the carb,the rear float was stuck,shut car off tap carb,restart alls good.Well I,m thinking when I shut it off,the gas ran into the cylinder and when I fired it up it pushed the cyl down on a up stroke,causing it to hydraulic and bend a rod.This is all I can think of as I,ve changed oil regularly and it,s been running like a top.:wack:
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Expensive learning experience! Electric Fuel pump?? So the next time the fix would be to take the spark plugs out, dis connect the spark Box, crank the engine over till all the fuel is out of the cylinders, change the oil and get back in line for the next run?

Sorry to hear about that Scott.
 
Mad Dart said:
Expensive learning experience! Electric Fuel pump?? So the next time the fix would be to take the spark plugs out, dis connect the spark Box, crank the engine over till all the fuel is out of the cylinders, change the oil and get back in line for the next run?

Sorry to hear about that Scott.
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Yes electric fuel pump,you are also correct about removing the plugs,changing the oil.It was time for a refresh anyway,just not this extensive.Lesson learned and will be back in time for spring.:cheers:
 
The one thing boost and does, ispressure the intake port.and the rotaion assembly.That gives you some leeway,until detonaton.With boost,this is a loaded question. I have seen personally,350 spray hits on a prepped 340. Block still lives today,every 10 passes it gets rings.(Low 9s,In florida)
 
I ran a 360 block for 4 years street and strip, stock crank, H Beam rods,studded main caps, and KB pistons. this engine never mist a beat. Made 407 hp and 401 tq to the rear tires. My intentions were to pull it apart and make it stronger for Nos. Well I put the nos on first,180 shot( mistake ) it made 545 hp and 569 tq to the rear tires. I got 4 passes out of it and it cratered.
Now I blaim the KB pistons, not really sure it made such a mess its hard to say.After reserching it I decided to go with the R3 eng just to be safe.

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scampman416 said:
I ran a 360 block for 4 years street and strip, stock crank, H Beam rods,studded main caps, and KB pistons. this engine never mist a beat. Made 407 hp and 401 tq to the rear tires. My intentions were to pull it apart and make it stronger for Nos. Well I put the nos on first,180 shot( mistake ) it made 545 hp and 569 tq to the rear tires. I got 4 passes out of it and it cratered.
Now I blaim the KB pistons, not really sure it made such a mess its hard to say.After reserching it I decided to go with the R3 eng just to be safe.

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I would agree with you that a piston failed and took everything with it. Those were cast pistons right? Looks like it because of all the pieces. These blocks are alot stronger than most give them credit for in my opinion.
 
Abodybomber said:
The one thing boost and does, ispressure the intake port.and the rotaion assembly.That gives you some leeway,until detonaton.With boost,this is a loaded question. I have seen personally,350 spray hits on a prepped 340. Block still lives today,every 10 passes it gets rings.(Low 9s,In florida)
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The block still lives!!! I would guesstimate at least 725-750hp,with a hit like that! That is alot of shock factor on the bottom end!

Thanks for sharing your experience!
 
Supershafts said:
I never used a stud girdle and put in 400hp on 2 stgs, i have broke cranks, pushed out gaskets, but not the block using n2o, but i leave off idle on the system and that seems to play mayhem on the bearings which will make them need changing more often.
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So would you guess about 800HP? You have some serious shock going on in the bottom end also!

Most of the failures here so far seem to be clearly from the other parts of the engine failing and then they take out the block.

Getting to the bottom of this 600HP myth, I appreciate your post!
 
Anybody have cap walk or cylinder movement first hand? Please jump in and post your experience & pictures if you have them!
 
TO MADDART,I need some psi talk at a later date,let me know....(By the way, that is on fctory rods.I prepped them in 93.)
 
Well I'm about to find out how well the stock block holds up. I'm thinking my new engine should be in the 650-670 range NA. Going to the track today for it's first passes. I'll let you know how it holds up.
 
Guitar Jones said:
Well I'm about to find out how well the stock block holds up. I'm thinking my new engine should be in the 650-670 range NA. Going to the track today for it's first passes. I'll let you know how it holds up.
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GJ, is this with your stroker that you did all the oiling mods to? Looking forward to your results. Should have Dynoed no? I guess your numbers at the track will give you a pretty good edgumakated guess on HP.
 
Abodybomber said:
The one thing boost and does, ispressure the intake port.and the rotaion assembly.That gives you some leeway,until detonaton.With boost,this is a loaded question. I have seen personally,350 spray hits on a prepped 340. Block still lives today,every 10 passes it gets rings.(Low 9s,In florida)
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=Abodybomber;(By the way, that is on fctory rods.I prepped them in 93.)
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So there goes another "Myth" that Stock Rods will break at 500ish HP" This combination has got to be 225-250HP above the limit that everyone seems to put on Stock Rods!
 
Guitar Jones said:
Well I'm about to find out how well the stock block holds up. I'm thinking my new engine should be in the 650-670 range NA. Going to the track today for it's first passes. I'll let you know how it holds up.
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Glad to see you got it finished up! Let us know how it goes.:cheers:
 
made a 360 .030 over maybe 15 years ago
i RAN THIS ENGINE HARD I meen really hard

after 8 years I decided it was time to built a 408
BUT the girls friend I hade at this time was yelling at me
its still running and run strong so why would you
built an other engine

so I decide to put juice on it 125 shot
so I let you decide how much horses it made

360 .030 over
mp .590 cam 265 dur
crane 1.6 roller rocker
KB 191 piston
j heads fully ported 252 cfm @ .500 of lift
12.33 cr.
holley strip dominator
800 cfm carb

and I hade 125 shot of nitrous on top of it
ran like that for at least 8 years before running the juice

blew the heads gasket twice (felpro) WITH THE NITROUS
install oring and sce copper head hasket

ran the juice for 4 years even on the street (stupidity)
I sold this engine to my best friend
told him it need to be refresh but he decide
it was running fine so he kept it like that
he still run that engine for the last 4 years

now I run a 408 for the last 4 years
Im please with it it run great on premium fuel

best so far is 10.79 @ 129 mph in a 3200 pounds duster

and it will get nitrous thats for sure

Bob
 
I had a 360 block cracked through the valley, it was stock & out of a 78 truck...

I think the 600 limit is complete horse sht.

Aside from precise machining & assembly, I believe core shift & tune are the important factors.

JMO
 
I really think the bottom line of how much it can handle is really in the prep of the block and parts and how it's set up. Not having the rotating assembly balanced good enough will cause stress, high compression adds stress, etc. Then there's un-known's and things beyond our control such as weak spots in the castings of the block or rods. I think there are a lot of variables involved. There are going to be those who have pushed 800 HP out of a well built and regularly refreshed build, and then there will be those who break at 450HP.

For many of us, if we had a stock block engine grenade with 500HP, then we'd probably not try to push it that far again, and be under the impression that a stock block couldn't handle it (unless we found the source of failure to be something else).

I just think there are too many variables, and there's going to be all kinds of opinions, probably based on way more experience than I have, that will range from one end of the spectrum to the other.
 
scampman416 said:
I ran a 360 block for 4 years street and strip, stock crank, H Beam rods,studded main caps, and KB pistons. this engine never mist a beat. Made 407 hp and 401 tq to the rear tires. My intentions were to pull it apart and make it stronger for Nos. Well I put the nos on first,180 shot( mistake ) it made 545 hp and 569 tq to the rear tires. I got 4 passes out of it and it cratered.
Now I blaim the KB pistons, not really sure it made such a mess its hard to say.After reserching it I decided to go with the R3 eng just to be safe.

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They are advertised to handle that much shot, I believe the tune killed it.
I 'personally' would shy away from a stock cast crank @over 500hp...
but right on for making the power and living 4 passes.
 
1wild&crazyguy said:
They are advertised to handle that much shot, I believe the tune killed it.
I 'personally' would shy away from a stock cast crank @over 500hp...
but right on for making the power and living 4 passes.
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I agree that a bad tune will make havoc on engines, that's why I took all precautions on my tune and took advice from some of the best nos guy's I no, I am confident that the tune was with in limits of a safe tune. KB Hypertech pistons are highly not recommended for any nos, in fact stock pistons would have lasted longer. All I wanted was the one weekend out of this eng and I was pulling it (crank and pistons had already bean ordered. ) My R3 I built makes 650+ Hp on engine only, got my 71 Valiant 4spd street --race car into the 9s Not sure I will even put the Nos on it.
 
So what I want to know is "Where" are the guys that are supposedly "GURU" Small Block guys who always post that 600HP is a stock blocks limit?? People are taking what you say seriously and as if it is "GOD" speaking when you say these things, yet I have not found 1 piece of evidence from any of you as of yet....

Here is your chance to Prove all your talk.....

So again, lets see some Cap Walk Proof, Cylinder Wall Movement Proof or Block Breaking Proof that you all speak of on a regular basis........ Yes I am calling you out on it! This is not the time to be shy!
 
64physhy said:
I really think the bottom line of how much it can handle is really in the prep of the block and parts and how it's set up. Not having the rotating assembly balanced good enough will cause stress, high compression adds stress, etc. Then there's un-known's and things beyond our control such as weak spots in the castings of the block or rods. I think there are a lot of variables involved. There are going to be those who have pushed 800 HP out of a well built and regularly refreshed build, and then there will be those who break at 450HP.

For many of us, if we had a stock block engine grenade with 500HP, then we'd probably not try to push it that far again, and be under the impression that a stock block couldn't handle it (unless we found the source of failure to be something else).

I just think there are too many variables, and there's going to be all kinds of opinions, probably based on way more experience than I have, that will range from one end of the spectrum to the other.
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I agree that a well prepped block will for sure last alot longer than one that was just slapped together.

What I am trying to get the answer to is "where does the block actually fail, and at what power level" So far there is no evidence here in this thread that would answer this question. Most Block Failures are from the "Parts" finding their weak spots which have nothing to do with the block. You scatter a piston, you will take out a cylinder wall, bend the Rod and probably the crank etc, etc which I believe we all can agree on. I also believe that a "Bad" Tune will most definately take out the weak link which in most cases is not the Blocks Fault in any way, Period.

Lets see if these Heavy Hitting SBM guys chime in with their first hand experience on all the "CRAP" they talk on this subject. I am sick of them talking it with nothing to back up their play..... So far I am not convinced at all and will just about take the rest of their talk with a grain of salt from here on out!!
 
we ran many 340 blocked 358 motors back in the late 70s early 80s all pushing over 750hp on dirt with a two barrel carb. on alcohol had all kinds of failures rods cranks and pistons don't remember any block failures.some were TA blocks some were 4 bolt some not..BUT I KNOW all racing engines are going to the same place just some get there sooner than others.....Artie
 
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