Convince me to build LS instead of BBC!!!
http://www.crateenginedepot.com/stor...6YNIRmCaeC6fIs
What fun is that. In a big heavy Chevelle, it'll be a dog. He would have to give it to a builder, along with $10,000 to make it what he needs..
You started comparing
try talking about the obvious , head design, weight , piston angle. pros and cons. whats the hp rating per hundred pounds.
While no doubt BBC's have more potential to make more power due to larger cubes. there is no reason why you cant build an LS for around ( everyone has there own around figure) the same price as a BBC, for what it is that you are looking to do . you have your mind set on a BBC thats great there is nothing wrong with that and i dont think anyone in there right minds would tell you other wise. But dont think for a second that LS motors arent capible of big numbers too, apples to apples (CI) the LS series is a better design.
You can build 1000 fwhp with a ls motor reliably for under 20K.
A BBC block will be heavier than a comparable CI ls block, it has to because it is physically a larger engine.
There one in my garage thats 11.17 , with 1.8060ft , stock.
Yes its a ligher car, a much lighter car.
a nice shot of NOS or some psi in a Chevelle , will be a low 10 maybe 9sec ride witht he right chassis set-up.
Last edited by KHShapiro; Nov 6, 2007 at 04:35 PM. Reason: sentence was misleading
Is this not a fact.
Hundreds of pounds...Its a '70 Chevelle. The original iron block that was in there can't be much different than an aluminum BBC block today.
Heads, BBC heads KILL any LSx head.
Piston angle...what does that have to do with anything????
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http://www.crateenginedepot.com/stor...6YNIRmCaeC6fIs
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The Best V8 Stories One Small Block at Time
http://www.crateenginedepot.com/stor...6YNIRmCaeC6fIs
I don't know man, over the past year or so, I've seen nothing but explosions and failures with all the TT LSx's and SC'ed big horsepower LSx's. No need to name members with these failed LSx big power engines. And all were less than 1,000 FWHP.
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Like I said, a BBC has a higher power potential than a ls motor. CI rule. That cannot be denied. All else being equal though, I will take a small block over a big block. When I said all else, I mean a comparable set of heads, compression, and intake. It will make the same if not more power and the weight difference makes even more of a difference. If you are looking at a 200 lb weight diffenrence, then you would need to make at least 50-75 more hp to run equal times. That is not even taking into account the location of the weight, which is in the worst possible place, over the front tires.

why is this?
. But i guess i have to take the blame here on that because i assumed you where refering to the LS7I pretty sure with equal amounts of money I could build a LSX 427 that would out perform the BBC 427 with , again equal amounts of money thrown at it, beyond stock versions
I dont know what the difference is between the Iron BBC and the Aluminum BBC block is but whats the price difference? how much more money does that add up to on your BBC build, and its still heavier than an LS
Heads are totally different, again I think ETP , AFR and others would fight you on this.
Piston angle , was a mistake I was referring to the head angle as in my pervious post .
what do you want Quickin? YES a BBC can acheive more than an LS once you pass the limits of the CI limitations on the LS blocks. but not before.
There are pleanty of LSX out there in the 1000hp range, search button works wonders, and its about the same price as the BBC versions.
Why, cost. what cost, the cost of the conversion and hunting down parts. getting the engine right where you want it and not some company that sends you motor plates and tells you where they want you to have it. Headers, where do you get LS headers for a G-body.. ( it is a G-body right, chevelle?) did you car come with a BBC , maybe you wont have to change springs. Converting to late model regs can be costly and very time consuming. Stick with the BBC idea, either way it doesnt really matter how you get there just as long as you do... 9sec will be in your future anyway with a proper build.
Good Luck to you
Stock BBC heads don't kill stock ls7 heads. But a bad *** set of 360 trick flows do
...I agree with the rod angle ratio. Its not that big of a deal.
When you get a 235cc head for an LSX and a 357cc head for a BBC there is a big difference. But the 235cc LSX heads usually aren't that far off flow wise to a 345+cc big block head.

A 427 LSx will WHIP a 427 BBC. The ENGINE is better, and cube for cube, there's no contest. The fact that the BBC can be expanded for more cubes (only a matter of time before the tall-deck LSx takes 'em down, too) doesn't make it better, it makes it bigger. Not saying the BBC isn't a good engine, but there's a reason we're using 6.0s and 6.2s in Trucks now instead of the old 8.1L BBC.
I dont know what the difference is between the Iron BBC and the Aluminum BBC block is but whats the price difference? how much more money does that add up to on your BBC build, and its still heavier than an LS
Heads are totally different, again I think ETP , AFR and others would fight you on this.
Piston angle , was a mistake I was referring to the head angle as in my pervious post .
what do you want Quickin? YES a BBC can acheive more than an LS once you pass the limits of the CI limitations on the LS blocks. but not before.
Weight difference between an iron big block and all aluminum small block is HUGE.
But like said no replacement for displacement. Big blocks will always make more power.
I don't think we'll ever see an LS series engine taking the place of the sure 'nuff big-inch engines, but for the majority of bracket racers in the 9 second range, the big block's days as ruler of the roost are just about over.
There's still nothing like a big-inch big block tucked between the framerails of a muscle car. Put a huffer on it and it becomes pretty much unstreetable, though.
IMHO, they're both here to stay for the forseeable future. It's a matter of preference, both can make more reliable power than you can hope to hook up.
Hell, I'm gonna build one of each - the LS for my Corvette and a 565 for a shortwide street truck. They'll have completely different manners but both will serve the purpose they were built for quite well.
And its not me that wants the BBC, the thread started does, I'm waiting on a tall deck iron LSX to do my 481ci so it'll bolt right into my WS6. If a badass 1,000 hp PUMP GAS 632 BBC would fit without a crazy amount of fabbing, I would definitely do it!!!!!!
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Can you list some examples of LSX aluminum Block failures. just the block and not a part that broke and cracked the block. I know of one , which wasnt a failure so to speak. When W2W ( i think it was W2W, maybe it was Katech) tore down a motor that was in the 1400 FWHP range they noticed the mains started to walk and suggested putting a girld on to prevent that from happening.
Last edited by KHShapiro; Nov 6, 2007 at 07:28 PM.





