HP limitations of a 383 block

[GreenFish]

So in my pipe dreams of upgrades and changes to the cuda I would like to build a bit different motor. I would like to use a 383 block and a stroker kit to 438ci producing around 500hp.  Then perhaps force induction later down the road like a procharger, with the ability to run 700+ hp. 

So often when I bring up the low deck block stroker folks will suggest I use a 400 block instead of the 383 because it is stronger.  So my question is what limits the 383 or makes it weaker?  I cant Imagine the 383 would not be able to handle 500 hp.  But the 700 mark may possibly be pushing the envelope. 

What do I need to know and what are the actual facts not what you have heard?

thanks all!! 

[bad440]

The 383 block has the same potential as any other Mopar big block. This is news to me that the 400 block is stronger than the 383. If you are stroking, the only difference from the 400 is slightly less cubes. Most 383's came with steel cranks, but not in the case of the 400(more money). If you like the 383 go for it, you won't be sorry.

[Road_Runner]

Excellent article that explains it very well:

http://www.440source.com/blockinfo.htm

I've heard that 600 HP is at the top of the HP range for a 383 block.  If you were to add a block girdle, cross-drilled main caps etc. you could probably go higher, but a 400 block would be a whole lot cheaper.

Later, Jim

[GreenFish]

Excellent article that explains it very well:

http://www.440source.com/blockinfo.htm

I've heard that 600 HP is at the top of the HP range for a 383 block.  If you were to add a block girdle, cross-drilled main caps etc. you could probably go higher, but a 400 block would be a whole lot cheaper.

Later, Jim

Good info and it doesnt really say that the 383 is weak, just that the 400 is stronger than the 383 and the 440 for that matter.

[Road_Runner]

Good info and it doesnt really say that the 383 is weak, just that the 400 is stronger than the 383 and the 440 for that matter.

No, I totally agree. But since we were discussing 700+ HP with some kind of power adder, that's some serious power that will find the weakest point wherever it is.  I've read other articles that talked about how much stronger all of these blocks are than GM & other brand's blocks because the sides of the block extend down much farther down around the crank.  That's why our oil pans are so shallow compared to Chevys. I raced with a 383 back in the 70's with no failures, but honestly wasn't putting out anywhere near where Greenfish says he may go.  I'm a fan of 383's, they rev like a small block and make decent power for their size.

Later, Jim

[bad440]

You have to remember these blocks are very similar to the 426  hemi, main difference is crossbolted mains which can be done to the wedge block. Have you seen any weak hemi blocks lately?

[PlumCraZRT]

My machinist wasn't at all concerned about a stock setup at the 500hp range (where my stroker is).  Cap walk seemed to be the concern at the 700 hp range.

I would get cross-bolted mains and call it a day.

[ragtopdodge]

If you want to build a 383 for 600+ HP, just get a stud girdle.

Reason why folks use a 400 block as opposed to a 383 is that the 400 has a much bigger bore.  So with a 383, there's the possible issue of valve shrouding.

But if this is a street car, a bored and stroked 383 should be fine.  If you're going all-out racing, sure, get a 400.  Of course, if you're all-out racing, than you should get an aftermarket block anyways like a World block or Indy max Wedge.

[johannes]

Before considering adding a block girdle,....is there sufficient clearence downwards towards the lower steering mechanism?....you know that bar that almost touches the original oil pan....?

In my opinion HP is totally overrateted in our hobby.

Get an HONEST dyno test,...and you will find that it will take a seriously TWEAKED engine to make anything close to 1RWHP/cid.
Most importantly,....to get high HP you need high torque at high rpm....which spells camshafts making poor gas milage and poor driveability....which do not seem to borther the old farts that do not need a designated driver in the weekends anyway....
My advice,....live happily with your -300 rwhp 383cid.... DRIVE it, and enjoy it...

[GreenFish]

Before considering adding a block girdle,....is there sufficient clearence downwards towards the lower steering mechanism?....you know that bar that almost touches the original oil pan....?

In my opinion HP is totally overrateted in our hobby.

Get an HONEST dyno test,...and you will find that it will take a seriously TWEAKED engine to make anything close to 1RWHP/cid.
Most importantly,....to get high HP you need high torque at high rpm....which spells camshafts making poor gas milage and poor driveability....which do not seem to borther the old farts that do not need a designated driver in the weekends anyway....
My advice,....live happily with your -300 rwhp 383cid.... DRIVE it, and enjoy it...

You know funny you should say this, because I am torn between not caring one bit about power and wanting to get stupid power.  I may just build a nice 438 stoker 383 with a roller cam, so I have some good power but nothing crazy but still drives nice. maybe put an EFI on it.

[johannes]

.....,I am torn between not caring one bit about power and wanting to get stupid power....

May I suggest a compromise?...N2O as a power adder and a decently tame engine ?
I used solid roller lifters a few years back,....I absolutely hated the valve ticking noise.
In 2008 one of the lifters failed and ruined the whole engine...steel particles EVERYWHERE inside...

[PlumCraZRT]

You know funny you should say this, because I am torn between not caring one bit about power and wanting to get stupid power.  I may just build a nice 438 stoker 383 with a roller cam, so I have some good power but nothing crazy but still drives nice. maybe put an EFI on it.

Here's an easy 500hp with a 451:
http://www.cuda-challenger.com/cc/index.php?topic=31681.msg810115#msg810115