Block Limitations

ace940

Member
Oct 16, 2011
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im sure that this has been asked many times before but here we go. how much power can the stock 302 block withstand? ive heard 500 hp but ive also heard that the internals can handle that much power too. so that beggs the question why build a stock block if the block will split at the same power as the internals can handle. does the boss block handle more power? what about 351s?
 
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there is no certain number that all of sudden will break the block. i'm at 500 rwhp on a stroker with a factory block and it's held for years now. the general rule of thumb is 500 but that's not a law.
 
The general consensus is that 500 is the limit. Some have pushed it for more, whereas others have failed with less. A Boss block should be good for 1000+hp, but be ready to spend some serious $$$ to have one built. As far as why build up a stock block, the answer is simple: it can be done relatively cheaply - stock block 302's are a dime a dozen. Even though you will be limited on power output, 500 hp at the wheels is no joke.
 
It depends on how you make hp. Turbo and a good tune and 500rwhp shouldn't be a problem. It depends on how often you give it the beans and so forth. Most people build a stroker with a stock block. Even with a turbo kit you can have a fun ride at 500rwhp. If that's your goal, then I'll welcome you to the brake s#*t club. Cars with that much power brake stuff constantly. Don't think it's just about the engine. With a turbo stock block to the limit, be prepared to spend good money on a transmission and rear end. My last stock block 347 made 492rwhp/635rwtq and lasted 10 years and 85,000 miles before the thrust bearing wore out.

Kurt
 
how much boost would i have to run? assuming i would go for 500 hp? i would assume like 14 or 15 psi? and would i have to get a megasquirt or a piggyback to be able to tune it or can i get the stock ecu tuned
 
How hard you'll have to push your turbo(s) will depend on what you're working with. A stroker, with good H/C/I is going to require a lot less effort from your compressor than a basically stock engine.
 
how much boost would i have to run? assuming i would go for 500 hp? i would assume like 14 or 15 psi? and would i have to get a megasquirt or a piggyback to be able to tune it or can i get the stock ecu tuned

Yeah, it really depends on the heads and stuff. The less the restriction, the lower the manifold pressure will be at the 500rwhp mark.

Kurt
 
I know a guy who just split his DSS 331 block with an On3 turbo kit. The point is make sure you know what you are getting into with a turbo install. As far as tuning, you can get it done with a plug in chip like SCT or a Quarterhorse.
 
The HP you can make safely with a stock block is mostly with the tune and the rpm's of the engine. If the engine does not rattle (detonate) and the rev's are kept under 5,800 rpm you would be surprised what a stock block can take. But let it rattle once and you are done.
 
The HP you can make safely with a stock block is mostly with the tune and the rpm's of the engine. If the engine does not rattle (detonate) and the rev's are kept under 5,800 rpm you would be surprised what a stock block can take. But let it rattle once and you are done.

There is a lot of truth to that statement..... :nice:

Stock blocks are truly hit or miss, brokem them NA with 350RWHP and 7800rpm and had them last through 540RWHP/740RWTQ at 6700rpm N2O.

Just so you have an idea...

stock block based,Cast crank, forged rod and piston stroker shortblock is around $2000 (internals will take 600hp), make it forged crank $2500 (internals take 800hp), add a DART block and $4500(internals and block take 1200hp+)
 
The whole reason why my 89' 5.0 has a (331 cid) Scat cast steel crank and "I" beam rods is that I did not see the point in putting a 750 hp plus rated rotating assembly in a 500 hp (approx) rated stock block. It is also a way of keeping the car streetable. I will save the high HP and high $ rotating assembly for the high HP rated block. Once I go down that road, I am afraid the car will be more of a race only vehicle and I will lose the ability to realistically drive it on a daily basis.
 
i forgot about this thread... lets say i was trying to do 400 to 450 hp with stock heads and intake would this even be possible with an on3 single turbo kit? they seem legit and i haven't seen anything bad about them.