Power limits for LA small blocks?

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doogievlg

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I saw that this question has been asked before but I'm curious if anyone else has any recent builds or experience. I'm planning to build a small block stroker out of my 360. I'm going to use a forged kit with flat tops most likely and I would really like to put a procharger on it. I'm guessing the final number will be 600+ hp. Will a factory block handle that or will I have head gasket problems because of the stud lay out.
 
I have a teen stroker, I don't have any idea the hp. But I've been curious to your question as well. I've always wondered why import 4cyl have no problem making huge power with turbos. But small block mopars have some power level were they aren't durable enough to handle? Fella I work with just had his import dynod at over 700hp an runs it at bandimere with all 4 tires spinning. He's still working on that part.
 
I have a teen stroker, I don't have any idea the hp. But I've been curious to your question as well. I've always wondered why import 4cyl have no problem making huge power with turbos. But small block mopars have some power level were they aren't durable enough to handle? Fella I work with just had his import dynod at over 700hp an runs it at bandimere with all 4 tires spinning. He's still working on that part.
its because the blocks of those import 4 cylinders are actually designed for boosted applications. So they are made with a higher quality casting and with strength for the added boost in mind. Also, you're comparing blocks made 30-40 years ago to blocks made since the mid 90s mostly. Machining and technology have come a long way. Tolerances are tighter, materials are better etc. Ever taken apart a turbo'd import motor? The two that I have, had cross bolt mains and main girdles. and one, which was a twin turbo motor had main girdle with STUDS. There is still limits to those blocks as well, just higher.
 
I'd like to make a slight correction and add two cents to dukeboy's response.

If you think about it, the LA came out in '67, so the design is actually older than that poly replacement year.

Our engines were NEVER designed to do anything more than move people. Adding racing mods over the years from ourselves and with the factory, the engines ability to handle more power has been raised. From what stock can handle to what a race block can handle, those limits are unknown to me.

I'd love to know, but I think those
Numbers are in a state of flux, AKA, not a concreate number or level.

Take a good look at some of the import blocks. Stout blocks and methods found from various sources incorporated into there designs. The way I see there material is for certainly a lot closer to race ready than our stuff.

To the OP, various techniques have been employed over the years to help develop and maintain this type of power.

How you get there can introduce variables that other builds may not use. Perhaps that is builder dependent? I don't know.

The stock block has issues with sealing and introduced the race blocks with extra bosses for extra head bolts. If a stock block tries the same thing, there would be an issue under high pressure. What I remember of this issues was to "O" ring the block.

The next issues was block strength. Under the extreme stress, you'll split it in half. There really isn't anything out there to increase the block strength from being split down the middle. Hard block in the water passages help. How much is good? IDK. Or what other methods there are and ones that are
Proven!
 
I saw that this question has been asked before but I'm curious if anyone else has any recent builds or experience. I'm planning to build a small block stroker out of my 360. I'm going to use a forged kit with flat tops most likely and I would really like to put a procharger on it. I'm guessing the final number will be 600+ hp. Will a factory block handle that or will I have head gasket problems because of the stud lay out.


It will make more power, bearings will look better and ring seal will be much better with a race block.

Once you get past 500 HP you can really see it in bearing wear and ring seal. You have to run more bearing clearance to keep it from snagging a bearing. And ring seal with. P-car block is a crap shoot. Not so much with a leak down tester but when measuring blow by you really see it.

That's why when I had the chance to snag an X block I did it. Even with my 375 HP I wasn't taking any chances.
 
Sounds like I just need to get an LS:)


Only joking but the more I read on this topic the more it sounds like I may just want to build a nice screaming stroker and stay away from the power adders. It's a shame mopar has not come out with a block comparable to the LS as far as weight, strength and aftermarket parts go.
 
Sounds like I just need to get an LS:)


Only joking but the more I read on this topic the more it sounds like I may just want to build a nice screaming stroker and stay away from the power adders. It's a shame mopar has not come out with a block comparable to the LS as far as weight, strength and aftermarket parts go.
ehhhh Mopar has no control as far as aftermarket parts go. Lets face it, we are the red headed step child when compared to Chevy and Ford. The biggest reason that the LS has such aftermarket support is because its largely an improved design on the 350 small block that has been around for damn near 60 years. meaning there is millions of them out there. Never the less, they still cant beat the HEMI design.
 
The biggest reason that the LS has such aftermarket support is because its largely an improved design on the 350 small block that has been around for damn near 60 years. meaning there is millions of them out there. Never the less, they still cant beat the HEMI design.
Actually the LS shares absolutely not one single part, measurement, or design of the old small block Chevy.

Now bear with me... I'm not a Chevy guy looking to stir up crap on a Mopar board. I like all makes. Right now in my garage an LS and a hemi are currently cohabitating and I'm pretty well experienced with both engines. I personally can't think of even a remote hint of an advantage the hemi has.
 
The procharger is not a way to big safe power. It's driven off the crank, and as YR said, the blocks flex, the crank will flex, and you create problems. Best bet would be a turbo setup. Less stress on the front of the crank and more power potential at the wheels from the same boost. More money, but you're saving from spending on a real block.
To be honest I'm going to go Gen3 Hemi deal for my next big power deal because of the lack of real blocks for a cost I can afford.
 
Sounds like I just need to get an LS:)


Only joking but the more I read on this topic the more it sounds like I may just want to build a nice screaming stroker and stay away from the power adders. It's a shame mopar has not come out with a block comparable to the LS as far as weight, strength and aftermarket parts go.


An R block or an X block would do. You just have to find them. No one bought them when you could get them. Always been that way.

For every high HP mopars built there is 250 Chevy engines built. Maybe more. The numbers never work out.
 
An R block or an X block would do. You just have to find them. No one bought them when you could get them. Always been that way.

For every high HP mopars built there is 250 Chevy engines built. Maybe more. The numbers never work out.

I already have a good block. What is the typical price for an R or X block? New I see them for almost 3 grand. By the time I got the block and rotating assembly I would be at the price of buying a crate motor with a warranty.
 
To me when your shooting for above 500-550hp go big block.
 
I don't know what an R block or X block is, not that knowledgeable. But I saw no mention of the block being used in the Hellcat, or comparison of that engine to the LS engine.
 
Im not super informed about all this, but you gotta consider what exactly "last" is. I mean, fuelers only care about "lasting a quarter mile plus burnout and staging". Maybe four rounds.

Aluminum blocks can "last" a little longer because there is the chance of welding a window back up. IDK what all you could weld to save a block but it has to add to the "last factor".

I would like to know the answer to all this too.
 
For the guy that rarely goes full throttle it will last a long time. The guy that hammers on it is asking for a shorter life beyond 600hp. When the dude invents the crystal ball to determine what shorter means in miles or passes I'm sure there are multitudes of builders who will want to talk to him. Plus you'll spend a bunch to make it reliable at 600.
 
Actually the LS shares absolutely not one single part, measurement, or design of the old small block Chevy.

Now bear with me... I'm not a Chevy guy looking to stir up crap on a Mopar board. I like all makes. Right now in my garage an LS and a hemi are currently cohabitating and I'm pretty well experienced with both engines. I personally can't think of even a remote hint of an advantage the hemi has.
Actually the LS shares absolutely not one single part, measurement, or design of the old small block Chevy.

Now bear with me... I'm not a Chevy guy looking to stir up crap on a Mopar board. I like all makes. Right now in my garage an LS and a hemi are currently cohabitating and I'm pretty well experienced with both engines. I personally can't think of even a remote hint of an advantage the hemi has.

This post has a chance at really really derailing this thread haha but I appreciate the input.
 
This post has a chance at really really derailing this thread haha but I appreciate the input.
That's because some people like to bash a MoPar thoughtlessly through what they think is an intelligent conversation with mentions of items that you have no intention of using.

Forest Gump once said,
"Stupid is as stupid does."

Now back to the MoPar part of the program.....
 
I don't know what an R block or X block is, not that knowledgeable. But I saw no mention of the block being used in the Hellcat, or comparison of that engine to the LS engine.

Screw the Hellcat engine block and LS block designs. There not part of what needs to be done for a reliable high HP LA block in which this is about.
There more modern engines with updated design features which would be nice to have in our everyday blocks much like the imports I made mention of earlier also use.

But our blocks were never designed for racing, just people moving.

The X block was the first performance block released for the racer. It has a few nicer things about it that make it more durable and ridgid than stock blocks. The next in the series of racer blocks are the R blocks.

The are upgraded stock blocks that can hold some good power. The modern current system ocknengine block exceed the abilities of older race blocks.
(Or DANM well should!)


Im not super informed about all this, but you gotta consider what exactly "last" is. I mean, fuelers only care about "lasting a quarter mile plus burnout and staging". Maybe four rounds.

Aluminum blocks can "last" a little longer because there is the chance of welding a window back up. IDK what all you could weld to save a block but it has to add to the "last factor".

I would like to know the answer to all this too.

How long any engine will last before is a multitude of factors. Bust out your crystal ball for starters!
LMAO!

You could build a 500 hp engine that will last a half million miles if you drive like a scared old lady!!!
Or a 270 hp engine that will last months if you drive it like an insane teenager bent on revenge on a drug fuel rage!
 
What I am getting from this thread is either buy an x block and build the boosted set up, go with a big block, or changed my expectations and build a 500 hp small block.
 
What I am getting from this thread is either buy an x block and build the boosted set up, go with a big block, or changed my expectations and build a 500 hp small block.


Yes. If you are patient, you can find an X or R block for a reasonable price. I bought my last X block brand new, in the box, unbored for $800.00 cash.

A correctly prepped X or R block will take anything an LS will. Don't let the junk yard scrounges bullshit you. If you are making power with an LS, you are using an aftermarket block. Just like the SBC. My rules with SBC's was 500 HP for a circle burner or 575 HP for a drag car and you bought a block. If you didn't, it was built by someone else.

No one making big power RELIABLY is doing it with a stock block. If it was true, nobody would make locks in the aftermarket.


FWIW! You can make 550 HP falling off a log with a decent 408 and eddy heads. And that's using HRT's and turning 5500 RPM. If you don't RPM it's guts out (keep it under 7000) it will be as reliable as anything else.
 
Yes. If you are patient, you can find an X or R block for a reasonable price. I bought my last X block brand new, in the box, unbored for $800.00 cash.

A correctly prepped X or R block will take anything an LS will. Don't let the junk yard scrounges bullshit you. If you are making power with an LS, you are using an aftermarket block. Just like the SBC. My rules with SBC's was 500 HP for a circle burner or 575 HP for a drag car and you bought a block. If you didn't, it was built by someone else.

No one making big power RELIABLY is doing it with a stock block. If it was true, nobody would make locks in the aftermarket.


FWIW! You can make 550 HP falling off a log with a decent 408 and eddy heads. And that's using HRT's and turning 5500 RPM. If you don't RPM it's guts out (keep it under 7000) it will be as reliable as anything else.

I have the edelbrock heads already. While I am at a point in my life where I can build this thing right I am still trying to stick with the stock block. I got a feeling a 500 hp small block will be enough to keep my smiling for a few years until I decide what else to do.
 
What I am getting from this thread is either buy an x block and build the boosted set up, go with a big block, or changed my expectations and build a 500 hp small block.
Like 500 HP is ****? 500 HP is the ****!!!
 
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